It is really cool that 21 years later, I get to teach along side my mentor. I love to see when my students respond like I did so many years ago. It feels like watching that car leave the shop, purring like a kitten that no-one could fix and you did. When I see that light in my students faces, it feels just like that. What a rewarding career this has been.
a lot of people is questioning and not absorbing good info and tkz for effort, come on you are getting this for free I have been in automotive school and believe me you are paying a lot of money and getting poor info and not enough hand on vehicles . thank you Paul
Wow thank you! Most of my formal training came from the school I now teach at, Rosedale Tech. My instructor (who is still with us) was Dan Svitko. To this day I am still thankful for what he did for me and the knowledge he shared. For taking this long haired over partied teenager with no direction in life under his wing and showing me how to make a life for myself. Of course I absolutely loved electrical and electronic systems from the get go. I am still fascinated by it!
Last comment for the rest of you guys. If you have low or no fuel psi and you bypass a relay (like i did in this video) and now have good fuel pressure, you have a relay circuit problem. If your fuel psi is the same as when cranking or running then feel free to finish your power and ground tests with the relay bypassed. This will save your battery and starter motor in the case of a no start. Plus your friend doesn't need to crank the engine over & get pissed cause ur taking too long:-)
This is a great demo, thank you. Checking any pump by measuring pressures is an imperfect gauge of how well the pump works. Just like a voltage drop test, the best way to decide if a pump is bad is to see what volume it can put out (analogous to current rather than voltage). It would be nice to have a volume output test to help decide if any pump (water, or fuel, etc) is up to spec.... Older methods would have you put the fuel line in a safe bucket and measure output over 10 seconds, ha ha.
Joel thanks for the comment. I don't mind the questioning though. I think it is a good way to expand on the topic. As long as we all stay polite and be respectful to each other, I say the more the questioning the better the learning
Sure wished I'd found your video earlier. My 350 is doing everything you are showing. I just purchased a fuel pressure guage and I'm getting same readings as you.
Pinch the return line and check max psi. It is stays at 50, it's the pump, but check power and ground before dropping the tank. Also be sure to change the in-line fuel filter too!
A neat tip I learned was to use fingernail polish to cover up the holes in wire insulation caused by direct piercing the wire. Some RTV's emit ammonia when curing. Thanks for the cool videos.
my 2000 chevy s10 that I seldom drive, does the same thing, I thought it had a bad fuel pump but after putting it on the battery charger over night it started right up. This vid explains why perfectly.
thanks man, you don't know how much grief I get over doing that. the alternative here would be to replace the pump and cross your fingers that you don't have a wiring problem. and that is on acceptable in my eyes.
I have a 97 GMC K1500 and you duplicated my exact issue. Swapped out the fuel pump, put on a new fuel filter and it fixed the problem. Thanks for posting these helpful videos.
That makes sense, it probably would be unlikely that all injectors are clogged at once (unless it's been 20+ years and none were ever cleaned), and so the clogged/faulty ones would show up on that transducer test.
well as a rule of thumb a fuel pump will have an in-rush current of around 12-17A to get it spinning from static, so if you got yourself a little library of current captures from static you would get a quick idea of the in-rush current of a good working circuit & spot quickly one that has a volt drop.
If all the injectors are clogged, you are going to have some major running issues and severe lean misfiring which is easily identified using a scope and watching the secondary ignition waveforms. other than that, the timer tool is very reliable. you could also use a transducer in the fuel rail to ID
thank you for your help brother . i checked fuel pressure and only had 30 cranking so i put the pump in and its good to go. thank you for your help brother
Depending on the vehicle, it might be more work to cut a hole in the floor than to drop the tank anyway. It all depends on the tools you have available, such as a tall transmission jack and a helper. A full tank of gas is usually the only thing that makes it difficult short of stubborn tank straps.
The jumper wire is hooked to bat.neg and ran all the way to the back as close to the tank. It provides a known good ground for the multimeter to the two voltage tests, power and ground (while cranking).
i checked the video out. very helpful. if i am correct my fuel pressure is different but i am sure they all varry but i will recheck it tomorrow or friday and get back to you. but yea it starts on starting fluid and does the exact same thing as the 4.3 in your video. ill keep you updated on my progress. i remember saying when i was younger ill never mess with the newer cars and all that computer and diagnostic stuff but after working in repair shops i still find so many things that i learn every day . thanks for your help
OK thanks brother. I owe you for your help. What it is, I bought a 98 express 3500 work van for 400.00 last week and I am good at finding deals like that but I get the headache of figuring out the problem. Same with my 90 f150 and 2000 Durango. 500.00 each 2 years ago that I fixed and run strong today thank you
OK thanks brother. I owe you for your help. What it is, I bought a 98 express 3500 work van for 400.00 last week and I am good at finding deals like that but I get the headache of figuring out the problem. Same with my 90 f150 and 2000 Durango. 500.00 each 2 years ago that I fixed and run strong today thank you
You're allowed to question me, I make mistakes too. And you would not have been wrong in your approach. I chose this method because it allowed me to measure pump current from under the hood. If pump current measured good with low psi I would have skipped the power and ground test. That was the main point. Also when checking power and ground here in the rust belt by the time you ID the correct wires to test and find a good ground you overheated the starter and killed the battery
Paul where did you get your training in electrical theory ? I was trained as a industrial elect/instrumentation tech so I have a deep understanding on power and electronics . You are in the upper one tenth of one percent of techs! You are a natural instructor!!! Best videos on the tube!
I'm not questioning your methods, neither that the relay was at fault. When you activate the fuel pump and read battery voltage at the pump that only tells u that that wire is intact.Leaves out the rest of the relay circuit at question.I understand what u did, you saved yourself time with that test, I personally would have cranked it.
Very informative video! I've got a cranky Suburban that has rough running after warmup. Had to replace the fuel pump and the fuel pressure regulator last year. Was supecting maybe timing issues since when i'm in driving and RPMs are between 1000 and 2000 I get an occasional motor shake. Will tak another look at the fuel pressure readings. Have been seeing 50 lbs of pressure. 5.7L Vortec 1999 Suburban.
The ground scenario was only a suggestion, by the way what is the "low side and high voltage side"? I believe it is called "control" and "load" side of a relay.
As usual your videos are unmatched down to the minute details, which is everything. As you know what might be obvious to one person may be a complete mystery to another, thanks for recognizing that. One question though, what size fuse do you suggest for jumping the fuel pump?
hey brother , i didnt forget to get back to you we just had rain here so today was clear so i checked the fuel pressure and was only 30 cranking but i ordered a fuel pump and i put it in today and im good to go and thank you for your help i have another car that bugs me so ill explain in my next comment
Is high current draw from a fuel pump ,when you have low pressure at the rail,a good sign of a restricted fuel filter . P.S . Paul I just have to say I have learned more from your videos than I did in the school I attended.Not that the school was bad ,just overcrowded.This delivery method you use to teach (video) gives us the ability to absorb the information much more efficiently.
Can't count how many hundreds of these injectors I have replaced before they came out with the bulletin upgrade to multec injectors. Make them run much better.
You're jumping the fuel pump directly to battery voltage, bypassing the fuel pump relay. The computer controls the fuel pump relay control side and it is obvious that the relay is working because there is pressure,but you could have corrosion inside the relay affecting the load side(gray wire). I think the best test would be cranking the engine (load the circuit and let the relay do its job). I learned this from you. Also a faulty relay ground would affect load side voltage, wouldn't it.
I wish you would have had a video called "Accessing the fuel pump: How to lift, support, and NOT crack a fiberglass GM short box quarter panel that is made entirely of bodyfill that you didn't notice".....tomorrow is going to be an interesting day
Hi ....I purchased a used 1999 Chevrolet Astro van 4.3L V6 Vortex Motor I replaced the fuel pump fuel filter all relays coil distributor cap and rotor but my issue remains crank no start ....I'll be replacing all spark plugs wires pick up coil soon....as well as ignition module....but was wondering if you can suggest something I am over looking because I'm not getting any spark to the pump in order to get pressure....55psi.....also had an issue with passive key needed to do a key reprogram 10 minute intervals total of 3 = 30 minutes including 5 second off intervals total of 3 = 15 second intervals it cranked and ran for a solid 4 minutes then shut off ....keep having a weak battery issue....
that wouldn't have answered that question. pinching off the return line and checking max psi would have but this wasn't necessary either. IF the regulator was opening too soon causing the low psi, psi would NOT have increased with the engine running, in fact the engine would have never ran. Remember the psi at times was under 40 psi, then with a higher voltage applied (engine running) psi was almost normal (52 at idle, 58 on a snap).
also you mentioned a faulty relay ground. This would not effect load side voltage but would effect control side amperage and depending on the amount of resistance could cause the control side magnetic field to be too weak to latch the relay. So at that point there is NO fuel psi. So again this is not the problem as I had pressure......
sorry man. I'm a professional mechanic and instructor for the past 17 years. Don't get scared off by the fancy tools. A lot of what I do can be done using less expensive equipment.
ahh ok. any one of the four voltage channels. an amp probe reports a voltage signal as current flow. you can even use an amp clamp on a regular DVOM set in the DC volt mode.
Great info,I would have gone a little bit further before dropping the petrol tank on a older car with a corroded tank ,Why not cut a hole in the floor pan to access the connections on the fuel pump, which could be corroded, which your test poss. would not show
I a d issues with my 2000 Sonoma no start. issues.testd fuel relay was good, checked my ecm fuses all good, checked all fuses just for giggle all good, checked hot wire to pump , good, but the ground was shot, regrounded pump and started right away.
funny...a few days after I comment on this we have two vortec powered trucks in our shop with bad pumps. One will start and run with fluid and another has a completely dead pump
Mr danner in my area we have no good trainers teachers so, diagnostic techniques I have learn are from your book, video lecture and your you tube videos. how ever I have 00 chevy express 5.7 8 cyl, misfire cylinder 5 only under load ,I did fuel pressure test and current to pump dual channel on verus and pressure tranducer, but I am confused on all current to fp I have checked before I have seen amperage above 8 amps but on this while priming is about 7 amps ,cranking about 4 and running 0amp
Ok i see where your coming from but you're not thinking this all the way through. I agree that checking it with the relay involved is the most accurate, however if the relay was the problem I would have had normal pressure and amperage with the relay bypassed. I did not. Fuel psi never got any better (i should have shown that). But with the amperage being 3-5 amps lower than normal this was enough to say this is not a relay problem......
ScannerDanner going to brothers and check it out got the stuff in his shop pressure fuel gauge and computer go ahead and do the rest I saw on the video I no I didnt do all of it also had intake air leak that wasn't seen on air tun in the intake on bottom it has not yet not wonted to start sometimes runs little Rick if I just jump in start up so I jump in turn key on wait then start
These FPs will carry 8-10 amps. Running at 0 amps? That can't be. Where are you measuring the current flow from? IF it is from the FP test terminal, you can only use that with the engine off for an accurate measurement.
to places where I am wondering fuel pump, but I will check it close to the pump as well I will do voltage drop thaks for your advise , other is i do not like ignition pattern firing line on snap other cylinders about 20kv firing line and spark line less than 3kv , misfiring cylinder firing line 40kv and firing line at 12kv with normal burn time in your experience will this mean rich i am thinking as the injector poppet does not close and keep spraying, Thank you for your knowledge and your tim
Yeah i have a 90 Probe with the fuel sender unit/pump plate under the rear seat, and I have a 94 where they were too cheap to do the same. I would *never* trust myself to cut out the inspection hole exactly where it needs to be though the first time, I'd have to sacrifice one at the junkyard first for a trial. I don't see how you can accurately get it right the first time.
Okay but you're still in the same boat if current is too low.It could still be a bad electric motor (poor brush contact etc.) or low supply voltage or a poor ground. so you still need to check voltage to be sure.
How often do you do a volume test for a fuel pump? Would u consider it a most when checking the fuel pressure because I know pressure may be good but volume might show otherwise. Thanks love your videos
Im having the same issue on a 99 tahoe 5.7 csi. Exact same situation. Only thing is that in the last 3 years this woukd be the 3rd pump being replaced counting the initial pump replaced. Replaced filters both times. Replaced connector once. Pressure holds for atleast 20 minutes at 50 n it will start with fluid after that it will start all day till next morning relay doesn't show signs of overheating burning. My question is what could cause pump to keep going out so frquently? Its a common issue as ive seen on the net. Customer was initially advised to not let tank go below 1/4. But still
I had the same thing on a 1 ton cpi motor. . Heres a tip . when you start it your battery voltage goes to 14.5. if you let it sit a couple days static battery voltage drops to 12.5 or so. when this happens car wont start. fyi when you put a battery charger on it itll start to. oh an I had 60 psi at the valve . so check your battery 1 st
Hi Paul, never seen this before, great video, i have had a Bosch K Jetonic car that done simlar, but they have virtually no electrics on the fuel system, the injectors or purely opened by fuel pressure, i think they run around 50 or 70 pounds psi, i cant remember quite what it was but lot higher than electronic type...from Fred in England.
![New Fuel Pump - Still No Fuel Pressure - Now What? [2012 Ford E350]](http://i.ytimg.com/vi/GJ9O8pTkK4w/mqdefault.jpg)
![New Fuel Pump - Still No Fuel Pressure - Now What? [2012 Ford E350]](/img/tr.png)
It is really cool that 21 years later, I get to teach along side my mentor. I love to see when my students respond like I did so many years ago. It feels like watching that car leave the shop, purring like a kitten that no-one could fix and you did. When I see that light in my students faces, it feels just like that. What a rewarding career this has been.
Spot on sir. I had 45psi cold crank and no fire on one of these. New fuel pump and it starts perfectly.
Nice Video! The 95-up 4.3L (VIN code "W") (RPO L-35) motor needs 60 PSI minimum to start cold ,and the pump should "Dead Head" @ 72+ PSI
a lot of people is questioning and not absorbing good info and tkz for effort, come on you are getting this for free I have been in automotive school and believe me you are paying a lot of money and getting poor info and not enough hand on vehicles . thank you Paul
Wow thank you! Most of my formal training came from the school I now teach at, Rosedale Tech. My instructor (who is still with us) was Dan Svitko. To this day I am still thankful for what he did for me and the knowledge he shared. For taking this long haired over partied teenager with no direction in life under his wing and showing me how to make a life for myself. Of course I absolutely loved electrical and electronic systems from the get go. I am still fascinated by it!
Last comment for the rest of you guys. If you have low or no fuel psi and you bypass a relay (like i did in this video) and now have good fuel pressure, you have a relay circuit problem. If your fuel psi is the same as when cranking or running then feel free to finish your power and ground tests with the relay bypassed. This will save your battery and starter motor in the case of a no start. Plus your friend doesn't need to crank the engine over & get pissed cause ur taking too long:-)
This is a great demo, thank you.
Checking any pump by measuring pressures is an imperfect gauge of how well the pump works. Just like a voltage drop test, the best way to decide if a pump is bad is to see what volume it can put out (analogous to current rather than voltage). It would be nice to have a volume output test to help decide if any pump (water, or fuel, etc) is up to spec.... Older methods would have you put the fuel line in a safe bucket and measure output over 10 seconds, ha ha.
Joel thanks for the comment. I don't mind the questioning though. I think it is a good way to expand on the topic. As long as we all stay polite and be respectful to each other, I say the more the questioning the better the learning
Sure wished I'd found your video earlier. My 350 is doing everything you are showing. I just purchased a fuel pressure guage and I'm getting same readings as you.
Pinch the return line and check max psi. It is stays at 50, it's the pump, but check power and ground before dropping the tank. Also be sure to change the in-line fuel filter too!
A neat tip I learned was to use fingernail polish to cover up the holes in wire insulation caused by direct piercing the wire. Some RTV's emit ammonia when curing. Thanks for the cool videos.
my 2000 chevy s10 that I seldom drive, does the same thing, I thought it had a bad fuel pump but after putting it on the battery charger over night it started right up. This vid explains why perfectly.
@@Junk_fishing101 just boost it 1 or 2 volts
thanks man, you don't know how much grief I get over doing that. the alternative here would be to replace the pump and cross your fingers that you don't have a wiring problem. and that is on acceptable in my eyes.
I have a 97 GMC K1500 and you duplicated my exact issue. Swapped out the fuel pump, put on a new fuel filter and it fixed the problem. Thanks for posting these helpful videos.
awesome! Thanks for watching!
Paul is just so inspiring it's sick. I am really thinking of moving to Pittsburgh to attend his school.
Just posted on similar situation on other video. It brought me here.
Going through this as I write, going for ground tests next as pump is brand new.
That makes sense, it probably would be unlikely that all injectors are clogged at once (unless it's been 20+ years and none were ever cleaned), and so the clogged/faulty ones would show up on that transducer test.
Thank you for solving my problem because everything you showed was what I was doing.
Then what was the problem?
well as a rule of thumb a fuel pump will have an in-rush current of around 12-17A to get it spinning from static, so if you got yourself a little library of current captures from static you would get a quick idea of the in-rush current of a good working circuit & spot quickly one that has a volt drop.
If all the injectors are clogged, you are going to have some major running issues and severe lean misfiring which is easily identified using a scope and watching the secondary ignition waveforms. other than that, the timer tool is very reliable. you could also use a transducer in the fuel rail to ID
thank you for your help brother . i checked fuel pressure and only had 30 cranking so i put the pump in and its good to go. thank you for your help brother
just GM for over 15 years. fortunately they killed it.
Depending on the vehicle, it might be more work to cut a hole in the floor than to drop the tank anyway. It all depends on the tools you have available, such as a tall transmission jack and a helper. A full tank of gas is usually the only thing that makes it difficult short of stubborn tank straps.
yes, as well as with the timer tool. I have found it to be very accurate. I'll have to do a video on the transducer in the rail.
Man I love dan... so much knowledge, so humble.. great guy. True gear head.. 👨🔧
Nothing wrong with a man loving another man especially a mechanic
Paul, thank you. Best fuel pump testing video I've seen so far.
i wish all tech teachers were this smart an had the pasion he has. i would be a tech vs hvacr tech.
Very good, nice and detailed description of the fuel system.
The jumper wire is hooked to bat.neg and ran all the way to the back as close to the tank. It provides a known good ground for the multimeter to the two voltage tests, power and ground (while cranking).
i checked the video out. very helpful. if i am correct my fuel pressure is different but i am sure they all varry but i will recheck it tomorrow or friday and get back to you. but yea it starts on starting fluid and does the exact same thing as the 4.3 in your video. ill keep you updated on my progress. i remember saying when i was younger ill never mess with the newer cars and all that computer and diagnostic stuff but after working in repair shops i still find so many things that i learn every day . thanks for your help
Same system bro. I'm sure of it. It's only different in the injector designs. Same exact pressure specs
OK thanks brother. I owe you for your help. What it is, I bought a 98 express 3500 work van for 400.00 last week and I am good at finding deals like that but I get the headache of figuring out the problem. Same with my 90 f150 and 2000 Durango. 500.00 each 2 years ago that I fixed and run strong today thank you
OK thanks brother. I owe you for your help. What it is, I bought a 98 express 3500 work van for 400.00 last week and I am good at finding deals like that but I get the headache of figuring out the problem. Same with my 90 f150 and 2000 Durango. 500.00 each 2 years ago that I fixed and run strong today thank you
You're allowed to question me, I make mistakes too. And you would not have been wrong in your approach. I chose this method because it allowed me to measure pump current from under the hood. If pump current measured good with low psi I would have skipped the power and ground test. That was the main point. Also when checking power and ground here in the rust belt by the time you ID the correct wires to test and find a good ground you overheated the starter and killed the battery
Paul where did you get your training in electrical theory ? I was trained as a industrial elect/instrumentation tech so I have a deep understanding on power and electronics . You are in the upper one tenth of one percent of techs! You are a natural instructor!!! Best videos on the tube!
I'm not questioning your methods, neither that the relay was at fault. When you activate the fuel pump and read battery voltage at the pump that only tells u that that wire is intact.Leaves out the rest of the relay circuit at question.I understand what u did, you saved yourself time with that test, I personally would have cranked it.
ok cool , ill check it again tomorrow or friday and go from ther and get a fuel pump. thanks for all the help. i owe you for your help.
It is and in that case would be worth replacing the filter and retesting psi.
Thanks for the compliment!
Very informative video! I've got a cranky Suburban that has rough running after warmup. Had to replace the fuel pump and the fuel pressure regulator last year. Was supecting maybe timing issues since when i'm in driving and RPMs are between 1000 and 2000 I get an occasional motor shake. Will tak another look at the fuel pressure readings. Have been seeing 50 lbs of pressure. 5.7L Vortec 1999 Suburban.
Fantastic Paul.Thanks!!
Thank you my 01 blazer has a fuel issue cranks and after a bit it kicks like it will start then dies. This was very helpful.
yes indeed, i've seen a 1lb pressure below the min cause a no start on the old 4.3 with poppet valves,but they redesigned the replacements
thanks man. i was feeling a little crappy until now :-)
dannner is awsome if i had more money i would fly in an go to danner school. guy is great man if i was a teen again
That is exactly correct my friend.
ahh, I see. That is a great tip! Thank you very much. I will add it to my "tool box"
The ground scenario was only a suggestion, by the way what is the "low side and high voltage side"? I believe it is called "control" and "load" side of a relay.
Great video Danner. Very good detail.
it is not necessary my friend. whatever your preference. i like a graphing multimeter myself
As usual your videos are unmatched down to the minute details, which is everything. As you know what might be obvious to one person may be a complete mystery to another, thanks for recognizing that. One question though, what size fuse do you suggest for jumping the fuel pump?
a 20 amp fuse will be fine my friend. Thank you!
4.3 l on this engine is from low to high 55psi /60/to 62 in perfect start up and running conditions thanks Mr.DS
Love your video! One of the best channels on RUclips period
hey brother , i didnt forget to get back to you we just had rain here so today was clear so i checked the fuel pressure and was only 30 cranking but i ordered a fuel pump and i put it in today and im good to go and thank you for your help i have another car that bugs me so ill explain in my next comment
Oo is my by
wow , what a quick response Thank you I was measuring on the fuse and on wiring diagram shows only one leg is share from same fuse to vcm only
Mainly because this was a no start complaint. I made it run with propane. So you want to match the conditionS of the car when you're doing teSting
I keep in mind, thanks scanner danner...
These have a vacuum fuel regulator that raises psi when vacuum decreases. Maybe that's why it stayed running also?
that's right, but if the in-rush currents good you know the circuits good & it's more likely the pump, it can be a good preliminary observation point.
How are you going to use that jumper wire in this case? You cannot get to the pump connector without lowering the gas tank?
Is high current draw from a fuel pump ,when you have low pressure at the rail,a good sign of a restricted fuel filter . P.S . Paul I just have to say I have learned more from your videos than I did in the school I attended.Not that the school was bad ,just overcrowded.This delivery method you use to teach (video) gives us the ability to absorb the information much more efficiently.
couldn't have said it better myself
you got it my friend
Good idea adding an external battery charger to keep the cranking VDC up...
Very professional.
By scoping the jumper wire while running you may have seen the amperage come within spec and could have ruled out bad power and ground to the pump.
Can't count how many hundreds of these injectors I have replaced before they came out with the bulletin upgrade to multec injectors. Make them run much better.
You're jumping the fuel pump directly to battery voltage, bypassing the fuel pump relay. The computer controls the fuel pump relay control side and it is obvious that the relay is working because there is pressure,but you could have corrosion inside the relay affecting the load side(gray wire). I think the best test would be cranking the engine (load the circuit and let the relay do its job). I learned this from you. Also a faulty relay ground would affect load side voltage, wouldn't it.
best videos ever show how to 1video
I wish you would have had a video called "Accessing the fuel pump: How to lift, support, and NOT crack a fiberglass GM short box quarter panel that is made entirely of bodyfill that you didn't notice".....tomorrow is going to be an interesting day
Hi ....I purchased a used 1999 Chevrolet Astro van 4.3L V6 Vortex Motor I replaced the fuel pump fuel filter all relays coil distributor cap and rotor but my issue remains crank no start ....I'll be replacing all spark plugs wires pick up coil soon....as well as ignition module....but was wondering if you can suggest something I am over looking because I'm not getting any spark to the pump in order to get pressure....55psi.....also had an issue with passive key needed to do a key reprogram 10 minute intervals total of 3 = 30 minutes including 5 second off intervals total of 3 = 15 second intervals it cranked and ran for a solid 4 minutes then shut off ....keep having a weak battery issue....
Thanks man.
that wouldn't have answered that question. pinching off the return line and checking max psi would have but this wasn't necessary either. IF the regulator was opening too soon causing the low psi, psi would NOT have increased with the engine running, in fact the engine would have never ran. Remember the psi at times was under 40 psi, then with a higher voltage applied (engine running) psi was almost normal (52 at idle, 58 on a snap).
Thanks again for another great video, I appreciate it a lot.
A ruptured fuel pressure regulator diaphragm or a fuel pressure problem would be my guess
your "fused jumper wire" LOL , thankfully that wire is gonna melt off real quick anyways .
Great thank a lot. Im a auto tech but wasn’t sure if 45 psi was enough.
also you mentioned a faulty relay ground. This would not effect load side voltage but would effect control side amperage and depending on the amount of resistance could cause the control side magnetic field to be too weak to latch the relay. So at that point there is NO fuel psi. So again this is not the problem as I had pressure......
thank you so much i have the exact same symptoms on a car at work
never. I do WOT psi testing and O2 signal voltage tests at WOT to ID a weak pump.
nice video. but started to glaze over when you broke out the fancy scan tool hahahaha
sorry man. I'm a professional mechanic and instructor for the past 17 years. Don't get scared off by the fancy tools. A lot of what I do can be done using less expensive equipment.
ahh ok. any one of the four voltage channels. an amp probe reports a voltage signal as current flow. you can even use an amp clamp on a regular DVOM set in the DC volt mode.
But if the oil pressure circuit is bad and the relay is good with it still start and run??? 03 monte carlo ss 3.8.
Great info,I would have gone a little bit further before dropping the petrol tank on a older car with a corroded tank ,Why not cut a hole in the floor pan to access the connections on the fuel pump, which could be corroded, which your test poss. would not show
I a d issues with my 2000 Sonoma no start. issues.testd fuel relay was good, checked my ecm fuses all good, checked all fuses just for giggle all good, checked hot wire to pump , good, but the ground was shot, regrounded pump and started right away.
funny...a few days after I comment on this we have two vortec powered trucks in our shop with bad pumps. One will start and run with fluid and another has a completely dead pump
CSFI system used in that 4.3L 96+ Vortec
Thanks for the video was helpful
Personal preference I guess. I have a long jumper wire I made (10 ft.) for these kind of testing, hooked up to battery neg. reducing my cranking time.
This is cool. Very intresting
TKS FOR YOU HELP
Great video, as always. Thank you Paul! And Happy New Year!
Mr danner in my area we have no good trainers teachers so, diagnostic techniques I have learn are from your book, video lecture and your you tube videos. how ever I have 00 chevy express 5.7 8 cyl, misfire cylinder 5 only under load ,I did fuel pressure test and current to pump dual channel on verus and pressure tranducer, but I am confused on all current to fp I have checked before I have seen amperage above 8 amps but on this while priming is about 7 amps ,cranking about 4 and running 0amp
Ok i see where your coming from but you're not thinking this all the way through. I agree that checking it with the relay involved is the most accurate, however if the relay was the problem I would have had normal pressure and amperage with the relay bypassed. I did not. Fuel psi never got any better (i should have shown that). But with the amperage being 3-5 amps lower than normal this was enough to say this is not a relay problem......
ScannerDanner going to brothers and check it out got the stuff in his shop pressure fuel gauge and computer go ahead and do the rest I saw on the video I no I didnt do all of it also had intake air leak that wasn't seen on air tun in the intake on bottom it has not yet not wonted to start sometimes runs little Rick if I just jump in start up so I jump in turn key on wait then start
ScannerDanner I got you
These FPs will carry 8-10 amps. Running at 0 amps? That can't be. Where are you measuring the current flow from? IF it is from the FP test terminal, you can only use that with the engine off for an accurate measurement.
to places where I am wondering fuel pump, but I will check it close to the pump as well I will do voltage drop thaks for your advise , other is i do not like ignition pattern firing line on snap other cylinders about 20kv firing line and spark line less than 3kv , misfiring cylinder firing line 40kv and firing line at 12kv with normal burn time in your experience will this mean rich i am thinking as the injector poppet does not close and keep spraying, Thank you for your knowledge and your tim
Yeah i have a 90 Probe with the fuel sender unit/pump plate under the rear seat, and I have a 94 where they were too cheap to do the same. I would *never* trust myself to cut out the inspection hole exactly where it needs to be though the first time, I'd have to sacrifice one at the junkyard first for a trial. I don't see how you can accurately get it right the first time.
If your lousy at body work, or its a beater just put a bed liner over the ugly
Okay but you're still in the same boat if current is too low.It could still be a bad electric motor (poor brush contact etc.) or low supply voltage or a poor ground. so you still need to check voltage to be sure.
yep
i guess i would but i need some type of baseline. what should i look for?
how accurate would it be and what are the variables?
thanks!
How often do you do a volume test for a fuel pump? Would u consider it a most when checking the fuel pressure because I know pressure may be good but volume might show otherwise. Thanks love your videos
Im having the same issue on a 99 tahoe 5.7 csi. Exact same situation. Only thing is that in the last 3 years this woukd be the 3rd pump being replaced counting the initial pump replaced. Replaced filters both times. Replaced connector once. Pressure holds for atleast 20 minutes at 50 n it will start with fluid after that it will start all day till next morning relay doesn't show signs of overheating burning. My question is what could cause pump to keep going out so frquently? Its a common issue as ive seen on the net. Customer was initially advised to not let tank go below 1/4. But still
I had the same thing on a 1 ton cpi motor. . Heres a tip . when you start it your battery voltage goes to 14.5. if you let it sit a couple days static battery voltage drops to 12.5 or so. when this happens car wont start. fyi when you put a battery charger on it itll start to. oh an I had 60 psi at the valve . so check your battery 1 st
Hi Paul, never seen this before, great video, i have had a Bosch K Jetonic car that done simlar, but they have virtually no electrics on the fuel system, the injectors or purely opened by fuel pressure, i think they run around 50 or 70 pounds psi, i cant remember quite what it was but lot higher than electronic type...from Fred in England.
I've had problems where the fuel pressure regulator inside the intake bleeding off pressure and produce the same symptoms.
yes im waiting too. why are you gonna dislike this one?
that may not be a bad number. you need to check the psi next