I think the wire from the fuse block to the pump getting hot was a clue. Either that wire is damaged somewhere between the pump and fuse block, or the pump is failing and drawing a ton of juice. If it were me, I'd run a known good wire straight from the battery to the connector at the tank and see if it stops acting up. But I'm sure by the time we're seeing this vid, Ray's already got it figured out.
Joe, may I inquire what type of juice is the wire from the fuse block supposed to use. My truck prefers Bilberry and Passion Fruit 😂🤣🤣. This question, as a young mechanic in a military unit, was asked of me by my Platoon Sgt. I was cornfused. He told ne to use proper terminology when speaking to the grunts and for PMCS purposes. We could use slang among the pkatoon but dealing with the operators use proper military terminology.
I was thinking about that too, long wire straight from the battery to the fuel pump and also check the ground side on the pump by example providing it a secondary ground.
Ray also had the negative cable off the battery when he had the Wife Unit try to crank the engine over. When you start doing dumb things, it is time to take a break... or burn it to the ground.
The things I'd do: 1.) Check the wires out at the relay to see if they're grounding out (other than the ground wire of course) 2.) Check for continuity on the wires by connecting one lead of the meter to one pin on the fuel pump plug and then testing all the ends at the relay location (repeat for each pin at the fuel pump ... this will help ensure that there is continuity only for the one wire) 3.) Run a temporary wire to replace the green with black tracer 4.) Do an amp load test on the fuel pump 5.) Find a way to test the fuel pressure near the pump 6.) Check the fuel lines for blockages (not just the filter) In my guesstimation, it's something electrical so I'd lean more on the 1 - 3 on my list. Reason for my guess is that the wire was hot, and I'm guessing that it got hot enough to melt the clamp that holds it in the fuse block. In my estimation, it could be that the wire is grounding out somewhere, the fuel pump is drawing more than it's supposed to or maybe even an intermittent short in the wire causing arcing inside the wire. Replacing the fuse block may have a similar issue with the wire falling out until the reason for it getting hot is corrected.
what i would do is feed the pump directly and see if it works properly, then if i get fuel pressure, i check the injectors, if that checks, i do a spark test on each plug in order, if that check, then it could a valve issue
The problem is a high resistance connection between the relay output and the pump itself. Not a pump problem it is a wiring to the pump problem. I thought I kept seeing while you were checking wiring voltages an initial near battery voltage and then an immediate low or no voltage reading. This will happen if you have a badly corroded wire that when put under any load the voltage will drop to nothing because the current demand increases. A number of times in your probing this seemed apparent. True the relay seat was messed up but might not bee the only problem - Green Crusties at work!
Might be right - especially with the hot (temperature not voltage) wire. But was watching another jeep fuel issue video and the voltage right at the pump seems to dance around quite a bit but doesn't drop to no voltage but might drop a couple volts. I'll have to go back and watch again I thought it dropped to about 9V?
Does it have a cigarette lighter...does that work...so if the phones dead also...which seems like that going to happen next,he should have a cigarette lighter phone plug adapter...
I learnt the hard way when I forgot my phone was on charge and left it behind. Luckily got it close to a gas station before it died and walked so i could use their phone to call the workshop for help lol.
Everybody gets frustrated troubleshooting at one time or another. I feel your pain brother! By now, I probably would've parked the jeep on the tracks and let Tropicana troubleshoot it! 🤣🤣🤣
What SMA Eric O do? Put a clamp on ammeter on the fuel pump power wire and watch the current draw when pump is running. It should be a fairly steady current draw of a few amps. If it is jumping around it could be bad wiring or probably the pump. To rule out the wiring, disconnect the fuel pump connector and connect a 4 amp test light( head light bulb) to pump feed pins with ignition in on position. This will give a constant load to the circuit. Measure the voltage at the light. Should be close to 12volts. If not , check for a voltage drop( more than 0.5 volts) from battery positive to the positive side at the connector and same for the battery negative to the negative side if the connector to narrow down which side is the problem . Wiggling wiring will show if there is a loose or bad connection. The ammeter current will fluctuate and the test lamp will fluctuate too. If all the wiring is solid then it a bad pump. Always check powers and grounds.
could be a wiring issue. with it cutting out with movement. after all, its a jeep and seen wetness and could have hidden green crusties. nothing is boring about diagnosing strange thing like this. definitely enjoy these vids where thinking outside the box is mandatory. thanks, ray.
Hey Ted. I think you are right on the money with the wiring. With that green wire getting hot, I am willing to bet either the wire has picked up resistance do to corrosion or it's getting hot because it is intermittently touching ground.
I watched these in reverse order and got to watch the diagnostic process knowing that the fuel tank was FUBAR. Your comments were spot on about it acting like it's running our of fuel and smelling fuel, knowing the tanks filter was clogged from debris in the fuel while poor quality previous repairs created the leaking fuel smell. Instead of it being some esoteric electrical issue, it was a much more basic cause. Occam's razor.
Ray, those spade lug terminals have a little spring tab that gets bent, and then lose their grip on the housing they can be pushed out. Should be able to bend it back out, unless it’s broken off, which can happen too. It didn’t look corroded, from the video, so it might be salvageable.
I like to use a dentist's pick. I pulled the PDU from a yj (I did feel bad for cutting the heart out of a poor smashed yj) and repinned the whole thing into a be a PDU for my second battery to power the rest of my 96 xj. Credit Bleeping jeep and very old video. Also did a switch panel with 5 factory xj fog lamp switches to control it. That took years to track down. 2 of the relays do my dual stock electric fan set up.
That relay terminal in the fuse block looked like the kind that's retained by a plastic tab in the socket; there may be no good repair short of getting a weatherproof external relay housing and moving the fuel pump relay into it. Chrysler made a good one for a warranty campaign on a bunch of vehicles about a decade back when they made the dumb move of soldering the fuel pump relay onto the PC board in the guts of the fuse panel. The part number for the relay kit is CSZDV621AA and there's a Mopar parts overstock outfit up in Lakeland that has a bunch of them left, at $16 per kit plus shipping.
Great video Ray! I purchased a car where someone had changed the fuel pump. They did not change the assembly only the pump. They did not properly connect the pump to the line on the assembly in the tank. The hose clamp they installed was below the barb. It could not build pressure because it was leaking inside the tank. Yes, I was getting misfires. Replaced the assembly and the car now runs great!
I had a 1976 Renegade with a similar problem of momentary stalling. I found a small hole in the fuel line, wrapped it with electrical tape and resolved the problem.
Suggestion, verify fuel condition good , then hook amp clamp on fuse loop to fuel pump. Amp draw and visual of pump motor contacts will give direction.Good luck!
As others have said the wire getting HOT is an indication. It could be either a Positive OR Ground issue. My quick diag would be to use an AC extension cord and run pos and neg directly from the battery to the pump. I love using AC extension cords for long run testing. Im not sure the backfiring is only fuel related. I would also hook a direct ground from the neg battery to the block and chassis. You mentioned the ground coming from the distributer so maybe thats a clue as well. I cant wait for the update. OH, take your phone next time too. :)
Good morning from me, nearly 3am and can't sleep.... Work in 4 hours...great. And don't worry Ray I've been there with a problem that took me and others 3 days to solve and we're on the clock. But when you find out what it is.... that's the best moment ever. For me it was two screened cables that had been repaired so bad the inner cores shorted to ground. Cables replaced, sorted.
I know ive said this before. You need to wrap the Intake fuel rails with Insulation. they get hot and cause the fuel to expand and not allow the injectors to get fuel into the motor. This is a Known common problem on the 4.0L Jeeps.
There’s a short on the wire from the fuse block to pump. Probably caused the connector to get hot enough to melt the fuse block itself which is why the connector won’t stay in its position anymore.
I am watching the jeep thing. My brother around 1980 bought a 74 Chevy originally from Florida. Would do what you are experiencing. Turned out there was over five gallons of sand in the gas tank. The filter sock in the tank would clog up and you let it sit and getting in and out of car caused the sand to drop down off the in tank sock filter and it would run fine.
@@captainchaos3174 After so many videos where Ray corrects the Oil Cap to make sure the writing is facing the correct way surprised he can be in the Jeep with the knob turned sideways! LOL
Had a similar problem on a 1970s car, which turned out to be the starter solenoid breaking down when hot. It didn't engage the starter but it did draw all the starting current taking power away from everything else. Never had it since and took days to find. Just a thought.
While growing up I had an ‘81 Monte Carlo that also had really weird gremlins. My thoughts are you have a rotted out wire down to the fuel pump, or ground. Upon putting electrons through the wire, it heats up the copper and causes it to move. Usually retracting and breaking the connection. Then it will cool and extend until it makes the connection again. Just to start the cycle again. So run an external wire to pump connector. Retest!
Had a similar issue on an old mercury. Fairly new vehicle at the time. Pickup filter sock in the tank would clog up with shavings when you drove it long distance and die. Would not restart. After it sat for a couple of hours Would work fine. Short trips where OK. Had it at the dealer several times until an old mechanic at the Ford dealer pulled the tank, cleaned it out and thru the sock away. Drove it for another 250k without issues.
A great video Ray! You made me realize "It is not just me" that the attempted fix of my jeep does similar things. Carry On Brother. I love my 3 Jeeps but they do drive me crazy sometimes.
I had a 79 Lincoln Continental that did the exact same thing. It turned out to be a part in the distributor cap that advanced or retarded the timing automatically. It was the electronic equivalent to vacuum advance, if I remember correctly. The car stared and ran absolutely fine when cold, but after about an hour and the part got hot enough, it would fail and cause timing issues. Very much like what your Jeep is doing.
I had a Pontiac ignition module to do the same thing. After it got hot would backfire and stall out. Took me 4 modules to finally find one that was good
An old test to check ignition module is to hook dwell meter to ignition lead . dwell should remain constant if you increase throttle and dwell changes.. module is bad...
my 84 nissan was exactly the opposite. Would stall when cold primarily, pour a little gas down the carb and started right back up and generally kept running. Very intermittent, I feel your pain Ray. I tried everything. Never did figure it out. Always drove with a gas can in the bed, just in case. Carb had a heater element in it. Suspected that was the issue, was planning to replace carb but sold it before I did.
i totally agree with @Steady Toker "YOU ALWAYS SAY" dont assume the job is done right when some one else have done.... if the tank not too full recheck the pump for proper install....
I enjoy watching you doing root tree analysis's on vehicles Ray. I have always like doing them on almost every problem because I'm a detailed oriented person myself.
If there is a screen at the fuel intake in the tank (usually on the in tank fuel pump) make sure it isn't so fine that it plugs easily. We had a big issue with that on the last year of the Ford Contour and Mercury Cougar. The only cure was to leave it off. Check the tank for contamination for such things as loose paper or a plastic bag that can get sucked to the screen then fall off when less flow is needed. Make sure the tank vents. See if the problem goes away with the cap off. Those are some things I encountered.
I know you watch Eric and Paul. I'm surprised you didn't test the circuit with a headlight bulb at the rear connector to load it. I'm leaning toward a tank full of rust dust destroying the new fuel pumps.
Another thing I came across in a Dodge van, the weak pump will overheat if there is not much fuel in the tank. How much fuel is in there. That low voltage from the bad relay might have damaged the pump.
These are the types of videos that I really like. Love watching Rays troubleshooting skills. Can't wait to see the finish. I had a relay for a fuel pump, that for 3 years, would randomly overheat and open. After a few minutes it would cool and work fine for months at a time, and then out of blue fail. It's was so mentally stressing. Especially after a fuel pump, two fuel filters, new fuel line, and new fuel rail.
wow, never thought id see this same issue, i had the same problem in my 93 cherokee Years ago, did it to me on the other side of town, ended up letting it cool and was able to get home. Turns out was a failing pump, only ever happened when i had around 1/4 or under of a tank of fuel. went through the issue 1 other time within a year of replacing it, just ordered a Quantum Fuel pump and been going strong for 3 years.
try to NEVER run a fuel tank down under a 1/4 ..... as the fuel pumps gets hot ( the fuel keeps it cool ... this lengthens the life of the fuel pump )..... this goes for all cars
I'm only 8:12 in, but wanted to comment, that this happened to me and it turned out to be the fuel pump, once it got hot it started doing exactly what was happening here.
I’d have started with a pump. I’d probably have also run a new power line from the box to the pump. You’ll have more time diagnosing and driving and rinsing and repeating than just throwing the parts cannon at it. Jeep parts are cheap and usually fairly easy to replace. I’d also remove the fuel line from the rail and blow air back through the line while you have everything disconnected. Of course, this is a project Jeep so I’d probably have already replaced the almost 30 year old fuel lines
Unless I'm very much mistaken that Jeep has sat for a while and likely has debris of some kind in the gas tank. I had a very similar problem, not in a Jeep, but in a Studebaker pickup. (1960 Champ). It had sat for quite a while and there was trash and rust in the gas tank. It would partly block the fuel pickup and the engine would starve for fuel. I drained the tank, put some chains in it along with a weak Draino solution, sealed up the openings and rolled and shook the thing. Enough of that got all the lose stuff free. A few good rinsings and never had any more trouble.
Ray in my humble opinion the problem lies in your catalytic converter. My sisters dodge had huge power loss after brief warmup turned out to be a catalytic converter.. Good luck brother!!
I keep thinking it's thermal related because it craps out once it's at op temp. I always look at the ignition, but since the fuel pressure is gooched, and the last minute of the video shows no improvement in pressure when fed direct, it has to be the motor in the pump taking a dive once it's heats up. That's just my guess but I'm sure you nailed it either way with that last discovery. Pump gets hot and fails.
Ray, with all the backfiring and popping out the exhaust, the problem is in the ignition. While there certainly were fuel issues, what you are experiencing is a bad control module. I ran into the exact same issue with a Chevy a few years ago. I chased fuel problems for about a year until it dawned on me that it was backfiring under a load. In my case, the ignition module...which has a variable dwell...was not functioning correctly and the dwell became "fixed" and was not adjusting as it should have been. Anyway, I would put in a new ignition module and see if that cures the problem.
Watching this reminds me of a horse my sister had when we were kids that would walk and run fine in the pasture. As soon as you put a saddle on him and start walking down the road he would start limping, but when you would turn him around to start heading home he would walk fine.
The last time I had this happen, it was the fuel pump. Pretty much identical symptoms. That one was on a late model Nissan van that didn't have a pressure test port. The telltale on it was that when the stumbles started, the O2 percentage went way high, indicating a super-lean mixture. But you already know the pump's part of the problem. What you need to check next is whether the tank is full of rustycrap from the time this Jeep has spent parked and not running. The inlet sock may be getting plugged up with sludge and particles, choking off the flow and taking out the pressure. Even with a plastic tank, dead fuel sludge and crusty flakes from the few metal parts of the pump and sending unit assembly can still add up to a dirty sock on the pump. By the way, if you can't get that relay terminal to snap back in, Mopar part CSZDV622AA is a kit with a relay, a short harness, and a weatherproof bracket; it was made for a warranty campaign to fix a goof on the fuseboxes of a bunch of 2008-2012 (or so) vehicles that had their fuel pump relays soldered to a PC board in the guts of the fuse panel. (Dumb idea.) There's a Mopar parts overstock place in Lakeland that has a bunch of them left at $16 each plus shipping. I grabbed a couple of extras. [Edit: Somebody at Chrysler apparently got hissy about those campaign parts being sold on the Net, but I still know of a source, just not as inexpensive.]
@@drrobert2120 I also had a Dodge van display similar symptoms when some damp fuel caused corrosion inside the fuel rails; the tiny flakes of rust would jam together in the injectors' inlet screens and choke off the flow, making it run progressively worse, but they'd loosen up enough when it was shut down to allow a lather-rinse-repeat cycle. The rails were out of production, so I ended up salvaging them via a soak in rust remover solution. It ran for another 100K before the windshield frame rotted out.
Just a thought on the fuel starvation. Some pre-2000 vintage cars had flexible hoses between the fuel pickup and the in-tank pump. With age, the soft hoses could fail. If the failure occurred above the fuel level in the tank, starvation could occur unless fuel was sloshing around in the tank; one test was to see if the starvation went away if the tank was full. At $5 a gallon it would be an expensive experiment to fill the tank to test that, but just offering that as a possible cause of the intermittent problem.
I've run I to this issue before Ray Ray. I made an extension for my fuel pressure tester so I could watch it while driving. Found the issue it was dropping to like 5psi when you floor it. Put another new fuel pump [it already had a new one] and problem solved
everytime from this day forward im saying "its a jeep thing" with anything anytime i work on a jeep. good diag and keepin up the humor. thanks rainmanray for the content
I think you may have solved the problem at the end of at least a way to solve it. Two things have occurred to me. Is there a floating membrane or piece of plastic in the tank that is wrapping itself around the fuel pickup . Or if there is a piece of hose that's not gas rated in the line it could be collapsing after a short time.
While of no help to you Ray, I agree with Ronald. It is great to see real mechanics fault find an issue and not a wizz kid plugging into a computer to tell him what is broken and what needs to be done to fix it.
Had a similar problem where the hose inside the fuel tank deteriorated to where it was sucking air if the fuel level got below where the hole in the hose was. Not sure what the fuel pump design is on the jeep but the symptom was exactly the same.
this was one of my favorite episodes yet and i have watched most of your uploads,, this reminds me of my father in his shop working on engines before those scan tools became a thing. troubleshooting and process of elimination fixing things. my father retired when computers became popular, he wasn't interested in fixing " rolling computers"
I had same warm start problems with my 93 same engine changed computer, all sensors $1300 later the problem was bad ground connection not sure which one, removed each of the grounds from the 5 studs on fire wall, cleaned paint from threads, replaced wires and made a redundant ground pigtail looping each stud on firewall to battery ground stud connection on engine block. I enjoy your channel Buddy Eubank Montgomery Alabama
You got 7 ish volts when you took a reading at the connector that connects to the fuel pump. You improved the connection at the fuse box but noticed that the ground side wire was getting hot. This means that the ground wire is likely corroded, nicked, or smashed (or all three) and needs to be replaced. Ohm the wire out to verify or run a temporary bypass wire with a long lead. I would ohm both wires out to verify that corrosion isn't becoming an issue on the power side as well. It is a jeep and those wires are on the bottom side of the jeep.... in Florida. All the bad things for wires.
So, when you were probing at the fuel pump connections at the rear, you were getting 7 volts, but at the panel 12.5. Wouldn't that indicate a potentially broken wire?
@Richard Craniumdefinitely a fair point and definitely needs to recheck at the rear. I've chased similar issues before, sometimes just walking away for a bit is the best course.
Ray, you could bypass the fuel system in the Jeep for a jerrycan with an external electrical fuelpump for a quick troubleshoot. Wires (positive side shunt) from the relay to the pump getting warm could also be indication of a dying/resistive coil from the fuel pump.
Hint: while fuse box apart, put (fuel pump) relay back in, then jam the connector thingy back on from the underside of the fuse box, making sure it has a tight connection. Then pack with 5-minute epoxy to keep the wire bit in there. Let set for at least an hour, then try continuing-of-Jeep-diagnostic procedure! 😊
@@pcspecialistpdx If tab is even there. Had something similar where corrosion assisted in the tab breaking off. I cut off the old connecter and added a new one.
You didn't check the ground coming back from the fuel pump. As a northerner... it's ALWAYS the ground. Make sure that you have good clean power connections to both sides of the fuel pump connector, and then re-test. Good luck!
You forgot to do the most important upgrade: setting it on fire🔥! Or in other words, make the internal combustion engine an external combustion engine! An extra “inspection port” in the engine block ought to help, plus a hot engine and a leaky fuel line. Also, don’t forget the “smoke screen” and “oil slick” mods; in no time, you’ll (sort of) be able to do stunts just like on Knight Rider! 😅
@@RainmanRaysRepairs , Ray, with all the backfiring and popping out the exhaust, the problem is in the ignition. While there certainly were fuel issues, what you are experiencing is a bad control module. I ran into the exact same issue with a Chevy a few years ago. I chased fuel problems for about a year until it dawned on me that it was backfiring under a load. In my case, the ignition module...which has a variable dwell...was not functioning correctly and the dwell became "fixed" and was not adjusting as it should have been. Anyway, I would put in a new ignition module and see if that cures the problem.
When you first looked at the relay block , you said the fuel pump relay was hot . Excessive heat on the relay suggest excessive current or intermittent/poor connection . The pump is new so it shouldn't be drawing excess current but the connections in the relay box are old , new does not necessarily mean good , but old does quite possibly mean bad .
I had the same problem with a customers jeep just like that one.n it turned out to be the pump pulling to many amps . N it burnt the wire off the same one ur on in the box..i put new end on n new pump .no more issues. Ur on the right track Ray.
I had a very similar problem to this years ago. Turned out to be the coil breaking down under load, it would be fine idling and running for 20 minutes or so then just start breaking down and start backfiring and stalling. Although there is definitely a problem with the relay, there is something else happening as well.
Yo Ray, you mentioned a heap of corrosion in the fuse box. Its possible for that corrosion to travel down the wire internally, both increasing the internal resistance of the wire, and reducing the amperage the wire can carry to the fuel pump. This could be the case and would explain why that wire was super hot when you touched it at one point. Less Amperage = fuel pump not operating at capacity = less volume of fuel being delivered. As resistance also increases with temperature, this would explain why the symptoms arent present when the car hasnt been operating for a while. The wire can carry enough amperage to adequately operate the fuel pump when cool, but doing so heats it up, and it kind of becomes a self feeding loop at that point. More resistance = more heat = more resistance etc etc until it cant even back out of a driveway. Try bypassing that wire completely and running another power source back to the pump for testing. If this is not the case, I would put money on the new pump being a dud from the factory, but the heat of that wire is a bit of a smoking gun for me.
I also agree with Harley, The wire getting hot and the lack of appropriate volts at the fuel pump and the fact that you eliminated the fuse box as the issue already all suggest to me that the wiring itself to the fuel pump is playing a part here. This is a 95 jeep so I assume the wiring is still original since the coloring appears to still match the diagram. If there is any damage to the wire it could be causing the internal resistance condition that Harley talks about. Try Harley's suggestion with replacing the wire? Maybe get it to the point where it is happening again before doing that for more easy A / B testing.
I had a 1983 Dodge Ram with a Slant-6 and an A-833 manual transmission. It had the infamous Chrysler Lean Burn computer mounted to the air cleaner. Forget OBD-1, this thing had NOTHING in the way of troubleshooting info. I did the parts cannon on the sensors and checked all vacuum lines for cracks or other leaks, and I gotta say the truck ran well after that. 25 MPG from a full-size pickup truck? Not bad. 1983? Wow. And yeah, the Slant-6 and A-833 four-speed overdrive.... man, I loved that truck. It did 75MPH all the way across Michigan many times, but acceleration was slow - I could have drag raced a garbage truck and the garbage truck would win. But it also had stump-pulling torque.
I LOVE that you showed the struggle! I teach math and break (I mean fix) things in my spare time. One of the best things you can do as a teacher is model the struggle! Thank you SO much for the way you verbalize your thought process and for posting a video that may seem like a failure to some, but was actually a HUGE success!
ray I know there are problems with this jeep that you are hammering away at with pretty good speed, but you definitely need to check out the 4wd actuation boot located on the axel and the PVC vacuum lines that come off of it, I would be surprised if its still in one piece, they leave just about every YJ stranded when you need the 4wd
With that Eaton he installed in the front I think he would be better to eliminate the disconnect completely as it is always seeing unequal input from each side.
Perhaps there's a short in the wire to the pump. Getting hot would be a pretty big clue. There's possibly an actual electrical issue in the pump's circuitry, but you DID see 7-9 volts at the tank side of the wire which again suggests a short or some sort of resistance issue between the fuse block and the tank. But that's just something I'd check if I were there to poke at it.
Had a similar situation but not on a Jeep. Mine was a stuck-open sluice gate in the MAF, fooling the electronics into thinking it was a hard press down on the gas pedal and delivering way too much fuel to the injectors, resulting in backfire, strong smell of fuel with a 'rollin coal' like exhaust cloud with the inability to recover speed when the gas pedal was subsequently floored. Only happened on a hot engine. The MAF gate was binding in its pivots due to thermal expansion and lack of lubrication. Cleaned of the pivots and crust off the gate perimeter, lubed the pivots and all was hunky-dory. Of course that's just my suggestion...I could be wrong.
I would replace the ignition module or the ditributor if the module id built into that. They will get hot and cut out or die then restart or restart after cooling down. Even if u hook them up to a tester they will pass because they arent hot. They are in the process of breaking down until they finally die. Seems like you've checked the fuel system unless the pump is doung the same thing
@@desotosky1372 some of the the old eletronic ignition systems had the ignition control sealed inside of the distributor coated in epoxy. If the module was bad you had to replace the whole thing thats why i saidcif it idnt seaked in the distributor. Nissan did that a lot not cant remember about jeep / chryster they could have if they used mitsubishi technology
One of the big advantages of experience. Different problems have different symptoms. I had an M880 (60's dodge 4x4) that died when you hit the throttle, idled just fine. Plugged fuel filter. While waiting for a new filter, flushed it by putting it in backwards. The liquid that came out looked like red mud.
Hilarious! I literally just went through the same exact issue. Brand new OEM fuel pump so I discounted that as the problem. Went through relay, pressure regulator, body grounds,.......it was the internal wiring of the new pump. Threw in an aftermarket and away we went. Lost a week of my life stuck in el Paso!!
A friend of mine bought an '84 Nissan 200SX used from a frustrated owner that decided to let it go at a dirt-cheap price because it wouldn't run right. I was following him home the day he bought it when suddenly the muffler exploded. The previous owner had tinkered with the air/fuel ratio, the car was running extremely rich, fumes and/or raw fuel built up on the muffler, and... KABLOOEY! He fixed it up, and it ran quite well. Digital dash worked, even the computerized voice announcements (BONG! Key is in the ignition.) Sometimes we'd trade cars for the day and I'd cruise around in it. Fun little car. Well, my friend was going to store it at his parents' house for the winter, and he asked me if I wanted to be the one to take it for its last drive of the year. HELL YEAH! So I'm carving up Connecticut backroads, sunroof open, good tune on the radio, tapping my foot on the driver's foot rest, and gradually the car begins to slow down until I had to pull over, and it was barely chugging at idle. My friend, when he caught up to me, asked me what happened. I told him, and that's when he revealed a weak connection to a computer module in the driver's footwell, wiggled that connector, the engine smoothed right out, and I brought it the remaining few miles to his mother's. (Not tapping my foot to the radio the rest of the way, that's for sure!)
I'm impressed with your diagnostic skills Ray. Too many techs would just start throwing parts at the problem instead of working through to find the real issue. Like others below, I think the hot wire is an important clue. Repairing Jeeps are a bit like whack-a-mole. Fix one problem and another pops up. Also, we should hear the Wife Unit call out "Got your phone?" now before every test drive. ;-)
on mine it was a bent shaft in the distributor, replaced the distributor and it solved the problem. It was crazy trying to figure it out. the shaft bent enough when the distributor got hot enough the shaft touched the metal plate inside and grounded itself out.
Australia here. When we usually see a jeep it's on fire. Seriously.. they have a big reputation for that here, and often it happens in peoples driveway. 🔥🔥🔥
I know the feeling. As a Jeep owner and a mechanic I feel ya. I would look more into the backfiring. Exhaust restriction? Don't know but good luck. I love these vids. Say hi to WifeUnit for me!
I had a similar issue with a GM Sierra. As soon as it warmed up, it would run rough and backfire. I accidently fixed it by replacing the Temp Sensor in order to fix my temp gauge. It ran great after the sensor replacement. However, It didn't fix the gauge problem. That turned out to be corroded circuit internally at the gauge. Replaced the gauge and good to go. I do own two Jeeps now so I am looking forward to the cause of your Jeep issue. By the way, Jeeps are famous for corroded ground wires and terminals as well as putting circuit junction boxes behind the wheel well.
Hey I know..I missed an upload...everyone needs time off sometimes :)
You're excused this time Ray,,,It IS the weekend after all
you do you pal
Aucorse you need time off or you think you are a robot 🤨🤔
No worries. Have one on us. 😊
You need a pressure transducer so you can log fuel pressure over time...
I think the wire from the fuse block to the pump getting hot was a clue. Either that wire is damaged somewhere between the pump and fuse block, or the pump is failing and drawing a ton of juice. If it were me, I'd run a known good wire straight from the battery to the connector at the tank and see if it stops acting up. But I'm sure by the time we're seeing this vid, Ray's already got it figured out.
My exact thinking when he said the wire was getting warm. Bypass it and check.
Joe, may I inquire what type of juice is the wire from the fuse block supposed to use. My truck prefers Bilberry and Passion Fruit 😂🤣🤣. This question, as a young mechanic in a military unit, was asked of me by my Platoon Sgt. I was cornfused. He told ne to use proper terminology when speaking to the grunts and for PMCS purposes. We could use slang among the pkatoon but dealing with the operators use proper military terminology.
I was thinking about that too, long wire straight from the battery to the fuel pump and also check the ground side on the pump by example providing it a secondary ground.
@@imfloridano5448 It's an older Wrangler, so it probably likes Prune. 😆
@JoeVK this is the way
I was thinking "you removed the starter relay!" a second before your guy said "you removed the starter relay". I love these videos.
I was thinking the same thing
Ray also had the negative cable off the battery when he had the Wife Unit try to crank the engine over. When you start doing dumb things, it is time to take a break... or burn it to the ground.
The things I'd do:
1.) Check the wires out at the relay to see if they're grounding out (other than the ground wire of course)
2.) Check for continuity on the wires by connecting one lead of the meter to one pin on the fuel pump plug and then testing all the ends at the relay location (repeat for each pin at the fuel pump ... this will help ensure that there is continuity only for the one wire)
3.) Run a temporary wire to replace the green with black tracer
4.) Do an amp load test on the fuel pump
5.) Find a way to test the fuel pressure near the pump
6.) Check the fuel lines for blockages (not just the filter)
In my guesstimation, it's something electrical so I'd lean more on the 1 - 3 on my list. Reason for my guess is that the wire was hot, and I'm guessing that it got hot enough to melt the clamp that holds it in the fuse block. In my estimation, it could be that the wire is grounding out somewhere, the fuel pump is drawing more than it's supposed to or maybe even an intermittent short in the wire causing arcing inside the wire.
Replacing the fuse block may have a similar issue with the wire falling out until the reason for it getting hot is corrected.
Estimation guesstimation used a lot there 😂
what i would do is feed the pump directly and see if it works properly, then if i get fuel pressure, i check the injectors, if that checks, i do a spark test on each plug in order, if that check, then it could a valve issue
“You piece of Jeep!” LOL. That pretty much sums it up. (I can relate) 😆
I enjoyed you telling him to start the Jeep while you had starter relay out. I was waiting for it to register.
Or the first crank with "The Wife Unit" after the negative terminal was disconnected?
Right was thinking is he testing him. But seemed more like he forgot. But new guy caught on quick lol
The problem is a high resistance connection between the relay output and the pump itself. Not a pump problem it is a wiring to the pump problem. I thought I kept seeing while you were checking wiring voltages an initial near battery voltage and then an immediate low or no voltage reading. This will happen if you have a badly corroded wire that when put under any load the voltage will drop to nothing because the current demand increases. A number of times in your probing this seemed apparent. True the relay seat was messed up but might not bee the only problem - Green Crusties at work!
Might be right - especially with the hot (temperature not voltage) wire. But was watching another jeep fuel issue video and the voltage right at the pump seems to dance around quite a bit but doesn't drop to no voltage but might drop a couple volts. I'll have to go back and watch again I thought it dropped to about 9V?
Definitely agree. After fixing the wiring then test the fuel pump which could have become victim to voltage issues.
It’s likely a straight run from the fuse block to the pump, so the wire itself may physically be bad.
Jeep wiring is a pain to diagnose. Best test bypass the relay to pump.
The FIRST words out of my mouth when I saw the opening were, "I hope he's brought a phone." RAY, ALWAYS ALWAYS bring a phone on a test drive.
Does it have a cigarette lighter...does that work...so if the phones dead also...which seems like that going to happen next,he should have a cigarette lighter phone plug adapter...
I learnt the hard way when I forgot my phone was on charge and left it behind. Luckily got it close to a gas station before it died and walked so i could use their phone to call the workshop for help lol.
Yup, found that one out !
Pre cell phone days...
Forget the phone... You should've just towed the rollback tow truck behind the jeep.
Everybody gets frustrated troubleshooting at one time or another. I feel your pain brother! By now, I probably would've parked the jeep on the tracks and let Tropicana troubleshoot it! 🤣🤣🤣
A new dance move cam, followed by mec cam
Jeeps unit and Tropicana train unit combine in the form of scrap metal
What SMA Eric O do? Put a clamp on ammeter on the fuel pump power wire and watch the current draw when pump is running. It should be a fairly steady current draw of a few amps. If it is jumping around it could be bad wiring or probably the pump. To rule out the wiring, disconnect the fuel pump connector and connect a 4 amp test light( head light bulb) to pump feed pins with ignition in on position. This will give a constant load to the circuit. Measure the voltage at the light. Should be close to 12volts. If not , check for a voltage drop( more than 0.5 volts) from battery positive to the positive side at the connector and same for the battery negative to the negative side if the connector to narrow down which side is the problem . Wiggling wiring will show if there is a loose or bad connection. The ammeter current will fluctuate and the test lamp will fluctuate too. If all the wiring is solid then it a bad pump. Always check powers and grounds.
could be a wiring issue. with it cutting out with movement. after all, its a jeep and seen wetness and could have hidden green crusties. nothing is boring about diagnosing strange thing like this. definitely enjoy these vids where thinking outside the box is mandatory.
thanks, ray.
Makes it that much sweeter when you do figure it out.
i think you got it right. if the wire is getting hot, then it will melt the plastic, and the the connecktor wil go down.
Hey Ted. I think you are right on the money with the wiring. With that green wire getting hot, I am willing to bet either the wire has picked up resistance do to corrosion or it's getting hot because it is intermittently touching ground.
It looks to me like you have lower voltage at the pump so maybe you have a wiring issue between the relay and the pump somewhere?
Could be crap in the tank sloshing around, periodically blocking the pickup?
Try a boat tank and pump, bypass the regular fuel supply.
I watched these in reverse order and got to watch the diagnostic process knowing that the fuel tank was FUBAR. Your comments were spot on about it acting like it's running our of fuel and smelling fuel, knowing the tanks filter was clogged from debris in the fuel while poor quality previous repairs created the leaking fuel smell. Instead of it being some esoteric electrical issue, it was a much more basic cause. Occam's razor.
Ray, those spade lug terminals have a little spring tab that gets bent, and then lose their grip on the housing they can be pushed out. Should be able to bend it back out, unless it’s broken off, which can happen too. It didn’t look corroded, from the video, so it might be salvageable.
Correct. The little sharp tab on connectors got push back. Take ultra tiny flat screwdriver and bend it back out
Unless FBx housing melted from heat & tab no longer engages.
I like to use a dentist's pick. I pulled the PDU from a yj (I did feel bad for cutting the heart out of a poor smashed yj) and repinned the whole thing into a be a PDU for my second battery to power the rest of my 96 xj. Credit Bleeping jeep and very old video. Also did a switch panel with 5 factory xj fog lamp switches to control it. That took years to track down. 2 of the relays do my dual stock electric fan set up.
That relay terminal in the fuse block looked like the kind that's retained by a plastic tab in the socket; there may be no good repair short of getting a weatherproof external relay housing and moving the fuel pump relay into it. Chrysler made a good one for a warranty campaign on a bunch of vehicles about a decade back when they made the dumb move of soldering the fuel pump relay onto the PC board in the guts of the fuse panel. The part number for the relay kit is CSZDV621AA and there's a Mopar parts overstock outfit up in Lakeland that has a bunch of them left, at $16 per kit plus shipping.
Great video Ray! I purchased a car where someone had changed the fuel pump. They did not change the assembly only the pump. They did not properly connect the pump to the line on the assembly in the tank. The hose clamp they installed was below the barb. It could not build pressure because it was leaking inside the tank. Yes, I was getting misfires. Replaced the assembly and the car now runs great!
Diagnostic episodes are my favorite episodes. I hope you have a part 2 of this. I got to know what it ends up being.
Same here. Enjoyed this one.
I had a 1976 Renegade with a similar problem of momentary stalling. I found a small hole in the fuel line, wrapped it with electrical tape and resolved the problem.
Suggestion, verify fuel condition good , then hook amp clamp on fuse loop to fuel pump. Amp draw and visual of pump motor contacts will give direction.Good luck!
As others have said the wire getting HOT is an indication. It could be either a Positive OR Ground issue. My quick diag would be to use an AC extension cord and run pos and neg directly from the battery to the pump. I love using AC extension cords for long run testing. Im not sure the backfiring is only fuel related. I would also hook a direct ground from the neg battery to the block and chassis. You mentioned the ground coming from the distributer so maybe thats a clue as well. I cant wait for the update. OH, take your phone next time too. :)
Love watching you diagnose things, Ray you are a wizard 🇨🇦
Glad you got additional help. Nice to have him handy to help you diagnose!
Good morning from me, nearly 3am and can't sleep.... Work in 4 hours...great. And don't worry Ray I've been there with a problem that took me and others 3 days to solve and we're on the clock. But when you find out what it is.... that's the best moment ever. For me it was two screened cables that had been repaired so bad the inner cores shorted to ground. Cables replaced, sorted.
I know ive said this before. You need to wrap the Intake fuel rails with Insulation. they get hot and cause the fuel to expand and not allow the injectors to get fuel into the motor. This is a Known common problem on the 4.0L Jeeps.
YES! I remember seeing this a while back!
Yes we still wave😊got to if you are a proud jeep owner. It's always exciting to see another jeep. It's a jeep thing!!!...
There’s a short on the wire from the fuse block to pump. Probably caused the connector to get hot enough to melt the fuse block itself which is why the connector won’t stay in its position anymore.
I am watching the jeep thing. My brother around 1980 bought a 74 Chevy originally from Florida. Would do what you are experiencing. Turned out there was over five gallons of sand in the gas tank. The filter sock in the tank would clog up and you let it sit and getting in and out of car caused the sand to drop down off the in tank sock filter and it would run fine.
I would check the fuel line and pump for dirt in it makes sense what you're saying have a great day
Attention Rainman!
The horn button needs immediate attention.
Thanks for all the great videos!
OH THE HUGE MANATEE I didn't even notice and now it can't be unseen.
And the gear lever knob as well... 😮
I'm glad someone else noticed that.
@@captainchaos3174 After so many videos where Ray corrects the Oil Cap to make sure the writing is facing the correct way surprised he can be in the Jeep with the knob turned sideways! LOL
Had a similar problem on a 1970s car, which turned out to be the starter solenoid breaking down when hot.
It didn't engage the starter but it did draw all the starting current taking power away from everything else.
Never had it since and took days to find.
Just a thought.
While growing up I had an ‘81 Monte Carlo that also had really weird gremlins. My thoughts are you have a rotted out wire down to the fuel pump, or ground. Upon putting electrons through the wire, it heats up the copper and causes it to move. Usually retracting and breaking the connection. Then it will cool and extend until it makes the connection again. Just to start the cycle again.
So run an external wire to pump connector. Retest!
Had a similar issue on an old mercury. Fairly new vehicle at the time. Pickup filter sock in the tank would clog up with shavings when you drove it long distance and die. Would not restart. After it sat for a couple of hours Would work fine. Short trips where OK. Had it at the dealer several times until an old mechanic at the Ford dealer pulled the tank, cleaned it out and thru the sock away. Drove it for another 250k without issues.
Yep this is what i thought as well
A great video Ray! You made me realize "It is not just me" that the attempted fix of my jeep does similar things. Carry On Brother. I love my 3 Jeeps but they do drive me crazy sometimes.
I had a 79 Lincoln Continental that did the exact same thing. It turned out to be a part in the distributor cap that advanced or retarded the timing automatically. It was the electronic equivalent to vacuum advance, if I remember correctly. The car stared and ran absolutely fine when cold, but after about an hour and the part got hot enough, it would fail and cause timing issues. Very much like what your Jeep is doing.
I had a Pontiac ignition module to do the same thing. After it got hot would backfire and stall out. Took me 4 modules to finally find one that was good
An old test to check ignition module is to hook dwell meter to ignition lead . dwell should remain constant if you increase throttle and dwell changes.. module is bad...
@Dr Robert Ray doesn't have the old school ignition testing stuff.
I know..but back then it was a surefire way of pass or fail diagnostic.
my 84 nissan was exactly the opposite. Would stall when cold primarily, pour a little gas down the carb and started right back up and generally kept running. Very intermittent, I feel your pain Ray. I tried everything. Never did figure it out. Always drove with a gas can in the bed, just in case. Carb had a heater element in it. Suspected that was the issue, was planning to replace carb but sold it before I did.
Run your own wires straight from the battery to the pump. I wouldn't trust that jeeps loom. Love your work!
i totally agree with @Steady Toker "YOU ALWAYS SAY" dont assume the job is done right when some one else have done.... if the tank not too full recheck the pump for proper install....
An absolute master class in diagnosis. Outstanding!!!!!!
I enjoy watching you doing root tree analysis's on vehicles Ray. I have always like doing them on almost every problem because I'm a detailed oriented person myself.
If there is a screen at the fuel intake in the tank (usually on the in tank fuel pump) make sure it isn't so fine that it plugs easily. We had a big issue with that on the last year of the Ford Contour and Mercury Cougar. The only cure was to leave it off.
Check the tank for contamination for such things as loose paper or a plastic bag that can get sucked to the screen then fall off when less flow is needed.
Make sure the tank vents. See if the problem goes away with the cap off.
Those are some things I encountered.
Ray is following a tried and true method as he always does. That's fix what you find and go from there.
I know you watch Eric and Paul. I'm surprised you didn't test the circuit with a headlight bulb at the rear connector to load it. I'm leaning toward a tank full of rust dust destroying the new fuel pumps.
Another thing I came across in a Dodge van, the weak pump will overheat if there is not much fuel in the tank.
How much fuel is in there. That low voltage from the bad relay might have damaged the pump.
These are the types of videos that I really like. Love watching Rays troubleshooting skills. Can't wait to see the finish. I had a relay for a fuel pump, that for 3 years, would randomly overheat and open. After a few minutes it would cool and work fine for months at a time, and then out of blue fail. It's was so mentally stressing. Especially after a fuel pump, two fuel filters, new fuel line, and new fuel rail.
Ouch That's a lot of Cannon parts!
wow, never thought id see this same issue, i had the same problem in my 93 cherokee Years ago, did it to me on the other side of town, ended up letting it cool and was able to get home. Turns out was a failing pump, only ever happened when i had around 1/4 or under of a tank of fuel. went through the issue 1 other time within a year of replacing it, just ordered a Quantum Fuel pump and been going strong for 3 years.
try to NEVER run a fuel tank down under a 1/4 ..... as the fuel pumps gets hot ( the fuel keeps it cool ... this lengthens the life of the fuel pump )..... this goes for all cars
I'm only 8:12 in, but wanted to comment, that this happened to me and it turned out to be the fuel pump, once it got hot it started doing exactly what was happening here.
I’d have started with a pump. I’d probably have also run a new power line from the box to the pump. You’ll have more time diagnosing and driving and rinsing and repeating than just throwing the parts cannon at it. Jeep parts are cheap and usually fairly easy to replace. I’d also remove the fuel line from the rail and blow air back through the line while you have everything disconnected. Of course, this is a project Jeep so I’d probably have already replaced the almost 30 year old fuel lines
Unless I'm very much mistaken that Jeep has sat for a while and likely has debris of some kind in the gas tank.
I had a very similar problem, not in a Jeep, but in a Studebaker pickup. (1960 Champ). It had sat for quite a while and there was trash and rust in the gas tank. It would partly block the fuel pickup and the engine would starve for fuel.
I drained the tank, put some chains in it along with a weak Draino solution, sealed up the openings and rolled and shook the thing. Enough of that got all the lose stuff free. A few good rinsings and never had any more trouble.
Ray in my humble opinion the problem lies in your catalytic converter. My sisters dodge had huge power loss after brief warmup turned out to be a catalytic converter.. Good luck brother!!
I keep thinking it's thermal related because it craps out once it's at op temp. I always look at the ignition, but since the fuel pressure is gooched, and the last minute of the video shows no improvement in pressure when fed direct, it has to be the motor in the pump taking a dive once it's heats up. That's just my guess but I'm sure you nailed it either way with that last discovery. Pump gets hot and fails.
Ray, with all the backfiring and popping out the exhaust, the problem is in the ignition. While there certainly were fuel issues, what you are experiencing is a bad control module. I ran into the exact same issue with a Chevy a few years ago. I chased fuel problems for about a year until it dawned on me that it was backfiring under a load. In my case, the ignition module...which has a variable dwell...was not functioning correctly and the dwell became "fixed" and was not adjusting as it should have been. Anyway, I would put in a new ignition module and see if that cures the problem.
Keep your parts delivery guys happy✌️
I still do the wave on my 395000 mile 97 jeep Wrangler sport
On my 89 I had a similar problem fixed by replacing the TPS and crank sensors, and the map as well since it was like 15 bucks at the time.
Watching this reminds me of a horse my sister had when we were kids that would walk and run fine in the pasture. As soon as you put a saddle on him and start walking down the road he would start limping, but when you would turn him around to start heading home he would walk fine.
What an actor lol!
Happy Sunday Ray. Half way onto a million subscribers. 🚀👨🏻⚕️
The last time I had this happen, it was the fuel pump. Pretty much identical symptoms. That one was on a late model Nissan van that didn't have a pressure test port. The telltale on it was that when the stumbles started, the O2 percentage went way high, indicating a super-lean mixture. But you already know the pump's part of the problem. What you need to check next is whether the tank is full of rustycrap from the time this Jeep has spent parked and not running. The inlet sock may be getting plugged up with sludge and particles, choking off the flow and taking out the pressure. Even with a plastic tank, dead fuel sludge and crusty flakes from the few metal parts of the pump and sending unit assembly can still add up to a dirty sock on the pump. By the way, if you can't get that relay terminal to snap back in, Mopar part CSZDV622AA is a kit with a relay, a short harness, and a weatherproof bracket; it was made for a warranty campaign to fix a goof on the fuseboxes of a bunch of 2008-2012 (or so) vehicles that had their fuel pump relays soldered to a PC board in the guts of the fuse panel. (Dumb idea.) There's a Mopar parts overstock place in Lakeland that has a bunch of them left at $16 each plus shipping. I grabbed a couple of extras. [Edit: Somebody at Chrysler apparently got hissy about those campaign parts being sold on the Net, but I still know of a source, just not as inexpensive.]
Good possibility!
Excellent! I thought the same about gas tank .If you find crud there may have contaminated filter and the line it self
@@drrobert2120 I also had a Dodge van display similar symptoms when some damp fuel caused corrosion inside the fuel rails; the tiny flakes of rust would jam together in the injectors' inlet screens and choke off the flow, making it run progressively worse, but they'd loosen up enough when it was shut down to allow a lather-rinse-repeat cycle. The rails were out of production, so I ended up salvaging them via a soak in rust remover solution. It ran for another 100K before the windshield frame rotted out.
Just a thought on the fuel starvation. Some pre-2000 vintage cars had flexible hoses between the fuel pickup and the in-tank pump. With age, the soft hoses could fail. If the failure occurred above the fuel level in the tank, starvation could occur unless fuel was sloshing around in the tank; one test was to see if the starvation went away if the tank was full. At $5 a gallon it would be an expensive experiment to fill the tank to test that, but just offering that as a possible cause of the intermittent problem.
I've run I to this issue before Ray Ray. I made an extension for my fuel pressure tester so I could watch it while driving. Found the issue it was dropping to like 5psi when you floor it. Put another new fuel pump [it already had a new one] and problem solved
everytime from this day forward im saying "its a jeep thing" with anything anytime i work on a jeep. good diag and keepin up the humor. thanks rainmanray for the content
I think you may have solved the problem at the end of at least a way to solve it. Two things have occurred to me. Is there a floating membrane or piece of plastic in the tank that is wrapping itself around the fuel pickup . Or if there is a piece of hose that's not gas rated in the line it could be collapsing after a short time.
While of no help to you Ray, I agree with Ronald. It is great to see real mechanics fault find an issue and not a wizz kid plugging into a computer to tell him what is broken and what needs to be done to fix it.
Had a similar problem where the hose inside the fuel tank deteriorated to where it was sucking air if the fuel level got below where the hole in the hose was. Not sure what the fuel pump design is on the jeep but the symptom was exactly the same.
Check for debris in tank clogging screen. Falls away when not running.
this was one of my favorite episodes yet and i have watched most of your uploads,, this reminds me of my father in his shop working on engines before those scan tools became a thing. troubleshooting and process of elimination fixing things. my father retired when computers became popular, he wasn't interested in fixing " rolling computers"
I had same warm start problems with my 93 same engine changed computer, all sensors $1300 later the problem was bad ground connection not sure which one, removed each of the grounds from the 5 studs on fire wall, cleaned paint from threads, replaced wires and made a redundant ground pigtail looping each stud on firewall to battery ground stud connection on engine block.
I enjoy your channel
Buddy Eubank
Montgomery Alabama
You got 7 ish volts when you took a reading at the connector that connects to the fuel pump. You improved the connection at the fuse box but noticed that the ground side wire was getting hot. This means that the ground wire is likely corroded, nicked, or smashed (or all three) and needs to be replaced. Ohm the wire out to verify or run a temporary bypass wire with a long lead. I would ohm both wires out to verify that corrosion isn't becoming an issue on the power side as well.
It is a jeep and those wires are on the bottom side of the jeep.... in Florida. All the bad things for wires.
So, when you were probing at the fuel pump connections at the rear, you were getting 7 volts, but at the panel 12.5. Wouldn't that indicate a potentially broken wire?
Or intermittent grounding was my thinking. My clue was when he grabbed the wire to the fuel pump and commented that it was hot to the touch.
@Richard Craniumdefinitely a fair point and definitely needs to recheck at the rear.
I've chased similar issues before, sometimes just walking away for a bit is the best course.
Ray, you could bypass the fuel system in the Jeep for a jerrycan with an external electrical fuelpump for a quick troubleshoot. Wires (positive side shunt) from the relay to the pump getting warm could also be indication of a dying/resistive coil from the fuel pump.
Hint: while fuse box apart, put (fuel pump) relay back in, then jam the connector thingy back on from the underside of the fuse box, making sure it has a tight connection. Then pack with 5-minute epoxy to keep the wire bit in there. Let set for at least an hour, then try continuing-of-Jeep-diagnostic procedure! 😊
Great advice! Hopefully he sees this
probably not necessary, he just needs to bend the tab that engages the housing. If that doesn't work, then proceed to your suggestion.
@@pcspecialistpdx If tab is even there. Had something similar where corrosion assisted in the tab breaking off. I cut off the old connecter and added a new one.
Heavens to Snidley Whiplash- nearly stuck on the train tracks!
You didn't check the ground coming back from the fuel pump.
As a northerner... it's ALWAYS the ground. Make sure that you have good clean power connections to both sides of the fuel pump connector, and then re-test.
Good luck!
I have complete confidence that Ray will figure it out.
You forgot to do the most important upgrade: setting it on fire🔥! Or in other words, make the internal combustion engine an external combustion engine! An extra “inspection port” in the engine block ought to help, plus a hot engine and a leaky fuel line. Also, don’t forget the “smoke screen” and “oil slick” mods; in no time, you’ll (sort of) be able to do stunts just like on Knight Rider! 😅
Jeeps suck ass
Why not? Paul Danner set his on fire at the convenience store. Remember Eric's closing line at the end of each video.
I see you have the money briefcase with you. Awesome.
It’s my stuff, ws headed home
@@RainmanRaysRepairs , Ray, with all the backfiring and popping out the exhaust, the problem is in the ignition. While there certainly were fuel issues, what you are experiencing is a bad control module. I ran into the exact same issue with a Chevy a few years ago. I chased fuel problems for about a year until it dawned on me that it was backfiring under a load. In my case, the ignition module...which has a variable dwell...was not functioning correctly and the dwell became "fixed" and was not adjusting as it should have been. Anyway, I would put in a new ignition module and see if that cures the problem.
When you first looked at the relay block , you said the fuel pump relay was hot . Excessive heat on the relay suggest excessive current or intermittent/poor connection . The pump is new so it shouldn't be drawing excess current but the connections in the relay box are old , new does not necessarily mean good , but old does quite possibly mean bad .
I had the same problem with a customers jeep just like that one.n it turned out to be the pump pulling to many amps . N it burnt the wire off the same one ur on in the box..i put new end on n new pump .no more issues. Ur on the right track Ray.
I had a very similar problem to this years ago. Turned out to be the coil breaking down under load, it would be fine idling and running for 20 minutes or so then just start breaking down and start backfiring and stalling.
Although there is definitely a problem with the relay, there is something else happening as well.
Seems like a coil failing to me as well.
Yo Ray, you mentioned a heap of corrosion in the fuse box. Its possible for that corrosion to travel down the wire internally, both increasing the internal resistance of the wire, and reducing the amperage the wire can carry to the fuel pump. This could be the case and would explain why that wire was super hot when you touched it at one point. Less Amperage = fuel pump not operating at capacity = less volume of fuel being delivered. As resistance also increases with temperature, this would explain why the symptoms arent present when the car hasnt been operating for a while. The wire can carry enough amperage to adequately operate the fuel pump when cool, but doing so heats it up, and it kind of becomes a self feeding loop at that point. More resistance = more heat = more resistance etc etc until it cant even back out of a driveway.
Try bypassing that wire completely and running another power source back to the pump for testing.
If this is not the case, I would put money on the new pump being a dud from the factory, but the heat of that wire is a bit of a smoking gun for me.
I agree with Harley. And try the lead to the fuel tank?
I also agree with Harley, The wire getting hot and the lack of appropriate volts at the fuel pump and the fact that you eliminated the fuse box as the issue already all suggest to me that the wiring itself to the fuel pump is playing a part here.
This is a 95 jeep so I assume the wiring is still original since the coloring appears to still match the diagram. If there is any damage to the wire it could be causing the internal resistance condition that Harley talks about. Try Harley's suggestion with replacing the wire? Maybe get it to the point where it is happening again before doing that for more easy A / B testing.
Maybe a bad ground at the pump?
Love the investigation into this jeep ,keep up the great content ray!
I had a 1983 Dodge Ram with a Slant-6 and an A-833 manual transmission. It had the infamous Chrysler Lean Burn computer mounted to the air cleaner. Forget OBD-1, this thing had NOTHING in the way of troubleshooting info. I did the parts cannon on the sensors and checked all vacuum lines for cracks or other leaks, and I gotta say the truck ran well after that. 25 MPG from a full-size pickup truck? Not bad. 1983? Wow. And yeah, the Slant-6 and A-833 four-speed overdrive.... man, I loved that truck. It did 75MPH all the way across Michigan many times, but acceleration was slow - I could have drag raced a garbage truck and the garbage truck would win. But it also had stump-pulling torque.
I LOVE that you showed the struggle! I teach math and break (I mean fix) things in my spare time. One of the best things you can do as a teacher is model the struggle! Thank you SO much for the way you verbalize your thought process and for posting a video that may seem like a failure to some, but was actually a HUGE success!
Not my first video from this channel but definitely the one that earned my subscription!
ray I know there are problems with this jeep that you are hammering away at with pretty good speed, but you definitely need to check out the 4wd actuation boot located on the axel and the PVC vacuum lines that come off of it, I would be surprised if its still in one piece, they leave just about every YJ stranded when you need the 4wd
With that Eaton he installed in the front I think he would be better to eliminate the disconnect completely as it is always seeing unequal input from each side.
Perhaps there's a short in the wire to the pump. Getting hot would be a pretty big clue. There's possibly an actual electrical issue in the pump's circuitry, but you DID see 7-9 volts at the tank side of the wire which again suggests a short or some sort of resistance issue between the fuse block and the tank. But that's just something I'd check if I were there to poke at it.
Voltage drop the circuit, this will show if you have a green wire
Had a similar situation but not on a Jeep. Mine was a stuck-open sluice gate in the MAF, fooling the electronics into thinking it was a hard press down on the gas pedal and delivering way too much fuel to the injectors, resulting in backfire, strong smell of fuel with a 'rollin coal' like exhaust cloud with the inability to recover speed when the gas pedal was subsequently floored.
Only happened on a hot engine. The MAF gate was binding in its pivots due to thermal expansion and lack of lubrication. Cleaned of the pivots and crust off the gate perimeter, lubed the pivots and all was hunky-dory. Of course that's just my suggestion...I could be wrong.
Sounds like a carb problem. My old Thunderbird did that. I rebuilt the carburetor. Then my TBI Lincoln did that and I replaced the coil. Fixed.
I would replace the ignition module or the ditributor if the module id built into that. They will get hot and cut out or die then restart or restart after cooling down. Even if u hook them up to a tester they will pass because they arent hot. They are in the process of breaking down until they finally die. Seems like you've checked the fuel system unless the pump is doung the same thing
A new distributor was installed in one of the earlier videos. I know, "just because it's new doesn't mean it's good".
@@desotosky1372 some of the the old eletronic ignition systems had the ignition control sealed inside of the distributor coated in epoxy. If the module was bad you had to replace the whole thing thats why i saidcif it idnt seaked in the distributor. Nissan did that a lot not cant remember about jeep / chryster they could have if they used mitsubishi technology
My wife has a JL Wrangler, and she still does the “Jeep salute.” She also gets annoyed when Jeep folks don’t return the wave!😅😂
Let me guess its a 4 door too? 4 Wheel drive Minivans.
Do the wave, not many back, duck but never been ducked, seems ta be a wrangler or cj thing, I've only got a old zj
Hers is a 2 door, who actually uses the thing to have some fun. She is not carting around any kids. Guessed wrong!
Maybe they don't return it because she's driving a Fiat??? Idk? 😂😂
@@CoolHandFlyer good. 4 door wrangler owners who never take the top or doors off are the worst.
Congratulations on 500,000 subscribers !
Also backfiring always sucks....
One of the big advantages of experience. Different problems have different symptoms. I had an M880 (60's dodge 4x4) that died when you hit the throttle, idled just fine. Plugged fuel filter. While waiting for a new filter, flushed it by putting it in backwards. The liquid that came out looked like red mud.
Hilarious! I literally just went through the same exact issue. Brand new OEM fuel pump so I discounted that as the problem. Went through relay, pressure regulator, body grounds,.......it was the internal wiring of the new pump. Threw in an aftermarket and away we went. Lost a week of my life stuck in el Paso!!
I was wondering how it was going to start without the starter relay plugged in.
Project Jeep is back. This going to be a good video.
Ray: "Lets roll the window down."
Jeep: Unzip plastic window. It's a Jeep thing.
Also Ray: I hate this Jeep. 😄
As painful as it was to watch this video it was still good educational content. Rainman becoming a great RUclips Influencer 🔧🔧🔧🔧🔧🔧🔧
Great work Ray old-school macanic work no computer all macanic.
I was a founding member of the Atlanta four wheel drive club in 1971. I miss those days.
Now you know why the muffler was blown out before
A friend of mine bought an '84 Nissan 200SX used from a frustrated owner that decided to let it go at a dirt-cheap price because it wouldn't run right. I was following him home the day he bought it when suddenly the muffler exploded. The previous owner had tinkered with the air/fuel ratio, the car was running extremely rich, fumes and/or raw fuel built up on the muffler, and... KABLOOEY!
He fixed it up, and it ran quite well. Digital dash worked, even the computerized voice announcements (BONG! Key is in the ignition.) Sometimes we'd trade cars for the day and I'd cruise around in it. Fun little car. Well, my friend was going to store it at his parents' house for the winter, and he asked me if I wanted to be the one to take it for its last drive of the year. HELL YEAH! So I'm carving up Connecticut backroads, sunroof open, good tune on the radio, tapping my foot on the driver's foot rest, and gradually the car begins to slow down until I had to pull over, and it was barely chugging at idle. My friend, when he caught up to me, asked me what happened. I told him, and that's when he revealed a weak connection to a computer module in the driver's footwell, wiggled that connector, the engine smoothed right out, and I brought it the remaining few miles to his mother's. (Not tapping my foot to the radio the rest of the way, that's for sure!)
I'm impressed with your diagnostic skills Ray. Too many techs would just start throwing parts at the problem instead of working through to find the real issue. Like others below, I think the hot wire is an important clue. Repairing Jeeps are a bit like whack-a-mole. Fix one problem and another pops up. Also, we should hear the Wife Unit call out "Got your phone?" now before every test drive. ;-)
That Jeep badge being sideways on steering wheel made the Jeep God's angry!😅
on mine it was a bent shaft in the distributor, replaced the distributor and it solved the problem. It was crazy trying to figure it out. the shaft bent enough when the distributor got hot enough the shaft touched the metal plate inside and grounded itself out.
Australia here. When we usually see a jeep it's on fire. Seriously.. they have a big reputation for that here, and often it happens in peoples driveway. 🔥🔥🔥
I know the feeling. As a Jeep owner and a mechanic I feel ya. I would look more into the backfiring. Exhaust restriction? Don't know but good luck. I love these vids. Say hi to WifeUnit for me!
Yup. Sometimes you just have to step away and clear your head. So glad you didn't end up on those tracks again though.
Nothing boring about it - learning something
This is not boring, Ray. The diags are the best
I had a similar issue with a GM Sierra. As soon as it warmed up, it would run rough and backfire. I accidently fixed it by replacing the Temp Sensor in order to fix my temp gauge. It ran great after the sensor replacement. However, It didn't fix the gauge problem. That turned out to be corroded circuit internally at the gauge. Replaced the gauge and good to go. I do own two Jeeps now so I am looking forward to the cause of your Jeep issue.
By the way, Jeeps are famous for corroded ground wires and terminals as well as putting circuit junction boxes behind the wheel well.