Good video; I am (was) having the same issue. My Jeep is the 4.2 with the Mopar EFI system. Longer story shortened; after getting it back from the shop because of the other 4.0l head (part of the long story) replaced back to the 4.2 head; I was heading back to the shop with a brake light and pedal issue (different story). My Jeep started to do the same thing, but worse. I got to the shop (barely) so they worked on the brake light and pedal issue then on the hesitation issue. They replaced the TPS and my ECM (with one that I had as a backup), I did not drive it home, I put it on my trailer and towed it home with my F-250. So on a test run around my neighborhood it started again. It would happen at around 174 degrees. It felt so much like vapor lock, so I when that route. I re-wrapped my fuel rail at the engine. I also replaced fuel filter and fuel pressure regulator and re-wrapped those fuel lines. That did not solve it. The fuel pump is fine, when the engine is cool up to that point the pressure is consistent at 40/45 psi. So then I replace the idle control motor, MAP & MAT sensors. Still same issue, one thing I noticed was when they got rid of the header (no one makes a smog legal one in CA anymore for that head) so we went to a manifold. So there was this big stainless steel pipe that could be putting out lot more heat causing vapor locking. So I wrapped that with my header cloth wrap. I also found that the connecting bolts were loose and the two plugs that are for the EGR and something else were loose, So I put high temp thread sealant on them. As I was looking at the exhaust I thought what about the O2 sensor. So I Googled O2 sensor issues. One of the symptoms is the hesitation and stalling. So I replaced the O2 sensor and it is running great. I got to and past the temperature and no issues. I drove it just up and down my street. I need to replace the thermostat because the engine will run too rich which is not good for the O2 sensor. If this did not fix it, I would follow the coil route. Well thanks for letting me post a book.
I had similar on my CJ7. It turned out to be a corroded connection on the line preceding the ignition coil. I disconnected the connection, cleaned it with electric cleaner and wire brush. Used a small file to lightly file the connector metal prongs. Put a light dielectric grease around the inside of connector - NOT on the metal surfaces. Plugged the connectors back together. Runs good now.
Take a look at your distributor pickup coil (camshaft position sensor sort of thing). Its the magnetic plate under the rotor in your distributor. Its the timing for the ignition rather than the crank shaft sensor once engine is running. I've got a 94 2.5l (225k miles) and have running issues that has grown more continuous and greater impact. Before was rough idle in colder weather. Then hard starting in colder weather, easier in warmer weather. Then long time to start, once started with rough idle, high (1600) then low (400) rpms, back and forth, some back firing through intake at idle and slight acceleration. Once running at engine temps, it was fine for months into spring/summer. Then recently, it cut out on the highway. Fuel pressure was checked (liked your vid on doing that) and its functioning fine. No issue with cutting out or low output. Replaced several 'sensors' since they are original: crank position sensor, air idle bypass valve, throttle position sensor, air intake temperature sensor. Haven't done the MAP, though tested (like in your video on that). Have new spark plugs, rotor and cap installed. Wires didn't appear physically an issue. I've down to timing. Could be slack in timing chain, could be slack in distributor teeth (to camshaft), could be the distributor pickup coil. Haven't gotten my timer out to see if the timing is consistent.
Two thing come to mind (I've dealt with the same issue on my 95 XJ). I ended up swapping out all the sensors (Except the CPS) I would recommend the coil (mine was cracked) and the fuel pressure regulator on the fuel rail. As it's an intermittent problem, pressure testing might not pick it up. At least yours isn't in the tank. (FPR) God bless and stay well.
It's worth a shot I would disconnect the negative cable and hold it in the positive cable post but leave the positive connected do that for 30 seconds it resets the ecu. It might think it's still the old crank position. I so it on my remix motor any time I put new sensors
I've seen a bad ground strap to the motor do this. sure seems like an electrical gremlin to me. I'd start by making sure I have a good ground to everything. including the fuel pump.
replace the distributor cap and rotor also the sensor inside the distributor. My 94 jeep 2.5l had the same issue. After replacing this items no more hesitation.
I have the same issue cuz my wire fraded. I took cap off took the rotor off and took the two bolts off on top and now I can’t seem to get tht metal thing off. Any ideas how? I can see the sensor too just need to take that last thing off
Dude this was exactly my problem on my 2015 Wrangler, and no one could figure it out until the check engine light came on and it gave the error code for bad crank sensor. I thought my clutch was going bad!
My 93 had a similar issue and it got worse and worse until I could hardly drive it. I put in a cheap TPS bought online and it fixed it for a few months then went out again. Then I bought a better one from a reputable auto parts store and it hasn’t done that in over a year now. My guess it’s that same thing with yours.
I have the exact same issue. After extensive research, it really looked like the culprit was the crankshaft position sensor. Also replaced with a cheap part and it also didn't change a thing. Put the original one back. I will stop trying to find the solution and just wait for your next video(s) 😅
Do them Jeep’s have a EGR valve? I’m not real familiar with those but I love a good diagnostic video. Hope you solve the issue , God bless you and your family?
Like to know where you got a crankshaft position sensor for it Jeep Cherokee for 10 bucks? I just paid $76 at AutoZone? The crankshaft position fixed the issue of my Jeep suddenly while driving but it did nothing for acceleration hesitation which is still an issue that I'm still having. Maybe it will fix this Jeep but does not fix hesitation in my Jeep it just fixed a different problem
Keep at it man . I love my YJ but she has something wrong and I still can't figure it out . She runs like a champ tell you start going up hills then it starts loosing power really bad . And backfires from somewhere in the engine bay any input on this would be great
@@JeepSolid I'll start looking into that in the morning. Thank you so much for what you do you have helped me so much with my jeep already if your right I'll buy you a cup of coffee sometime maybe at that YJ meet up you've talked about .
@@newcaloutdoors505that sounds like somethings getting clogged. I’m new to jeeps but my 00wj has 250k. Skips twice when cool then it’s fine. I think it’s tranny tho cause it sounds like high gear clutch is disengaged intermittently until I let off gas. If I don’t let off gas it will eventually shift with a loud bang from the torque converter (I think) no grinding or metal on metal sound for now. Funds and tools are an issue. Hope your jeeps runnin good 🦆
Well to me sounds like a tps problem or cam shaft sensor low fuel pressure while accelerating also could be the reason its just one of those tricky things
Did you end up figuring this out? Having same exact issue, put new injectors, fuel filter from mopar. Want to see if you fixed it some other way before I order a new fuel filter.
@@JeepSolid I think these things just get air bubbles in the gas line or something. My 97 XJ has occasionally done this since it was new (yes, I'm the only owner). I just call it a Jeep thing.
Almost sounds and looks like the distributor advance ( probably mechanical) is ground out or getting stuck as rpm is coming up...could be on the vacuum side if under load...Or the idle air solenoid is malfunctioning.. but the fast Drop in the Tach says to me to check the distributor..
@@JeepSolid yes to the coil, but in my 50yrs, never seen a coil go half bad, either they work or they don't.. and usually it's the primary side that has an open in the winding..
I was wondering if you know how to change the pick up call you in the distributor on a 1987 YJ 4.2 L I can’t seem to figure out how to take out that little pin without damaging anything
I’m having this issue to but it only starts hesitating after driving it for awhile. If anyone has any suggestions on what the problem could be please let me know
Sounds like something is getting HOT then acts up. Could be the coil ? It's not VAPOR LOCKING is it ? When the fuel rail gets hot & boils the fuel in it.
On my 96 XJ, I’ve added aluminum/fiberglass manifold insulation, pipe insulation on the fuel rail, and a thermostat control to the aux fan to alleviate hot start hesitation. It has almost eliminated the problem. Using ethanol-free gas also helps.
@@JeepSolid if you do get one skip the software and go straight to an app called HScope if you have an Android. You can run the hantek with your phone and the app design is brilliant.
I had a similar issue that turned out to be crank sensor. Couldn't see it using a multimeter. Would see the 5volt reference go to ground so thought it was good. With the oscilloscope you could see the signal drop out. You can use it to diagnose your TPS which could also cause similar issues. Good luck!
Dale, consider having a temperature or pressure drop performed between the inlet and the outlet of the catalytic converters. They may be starting to get obstructed or maybe a sensor. No diagnostic error reported?
the. places I would check. first. look inside. the cap. if it is. sooty. good Chance of a bad. coil. coils do go bad. in strange ways. if there is any question. replace. OT. there are cheep. I would check the. cam. posistion. pickup. those are pricey. and the sender you just. I just do not trust. cheep. that price. was too low. you need to get a better one. the cheep ones just don't live long. have fun. and thank you. C
Good video; I am (was) having the same issue. My Jeep is the 4.2 with the Mopar EFI system. Longer story shortened; after getting it back from the shop because of the other 4.0l head (part of the long story) replaced back to the 4.2 head; I was heading back to the shop with a brake light and pedal issue (different story). My Jeep started to do the same thing, but worse. I got to the shop (barely) so they worked on the brake light and pedal issue then on the hesitation issue. They replaced the TPS and my ECM (with one that I had as a backup), I did not drive it home, I put it on my trailer and towed it home with my F-250. So on a test run around my neighborhood it started again. It would happen at around 174 degrees. It felt so much like vapor lock, so I when that route. I re-wrapped my fuel rail at the engine. I also replaced fuel filter and fuel pressure regulator and re-wrapped those fuel lines. That did not solve it. The fuel pump is fine, when the engine is cool up to that point the pressure is consistent at 40/45 psi. So then I replace the idle control motor, MAP & MAT sensors. Still same issue, one thing I noticed was when they got rid of the header (no one makes a smog legal one in CA anymore for that head) so we went to a manifold. So there was this big stainless steel pipe that could be putting out lot more heat causing vapor locking. So I wrapped that with my header cloth wrap. I also found that the connecting bolts were loose and the two plugs that are for the EGR and something else were loose, So I put high temp thread sealant on them. As I was looking at the exhaust I thought what about the O2 sensor. So I Googled O2 sensor issues. One of the symptoms is the hesitation and stalling. So I replaced the O2 sensor and it is running great. I got to and past the temperature and no issues. I drove it just up and down my street. I need to replace the thermostat because the engine will run too rich which is not good for the O2 sensor. If this did not fix it, I would follow the coil route. Well thanks for letting me post a book.
I had similar on my CJ7. It turned out to be a corroded connection on the line preceding the ignition coil. I disconnected the connection, cleaned it with electric cleaner and wire brush. Used a small file to lightly file the connector metal prongs. Put a light dielectric grease around the inside of connector - NOT on the metal surfaces. Plugged the connectors back together. Runs good now.
Take a look at your distributor pickup coil (camshaft position sensor sort of thing). Its the magnetic plate under the rotor in your distributor. Its the timing for the ignition rather than the crank shaft sensor once engine is running.
I've got a 94 2.5l (225k miles) and have running issues that has grown more continuous and greater impact. Before was rough idle in colder weather. Then hard starting in colder weather, easier in warmer weather. Then long time to start, once started with rough idle, high (1600) then low (400) rpms, back and forth, some back firing through intake at idle and slight acceleration. Once running at engine temps, it was fine for months into spring/summer. Then recently, it cut out on the highway. Fuel pressure was checked (liked your vid on doing that) and its functioning fine. No issue with cutting out or low output. Replaced several 'sensors' since they are original: crank position sensor, air idle bypass valve, throttle position sensor, air intake temperature sensor. Haven't done the MAP, though tested (like in your video on that). Have new spark plugs, rotor and cap installed. Wires didn't appear physically an issue.
I've down to timing. Could be slack in timing chain, could be slack in distributor teeth (to camshaft), could be the distributor pickup coil. Haven't gotten my timer out to see if the timing is consistent.
Man you're the best! thanks for all the help.
In the past, high speed miss was linked to coil problems. Also, camshaft position sensor.
Two thing come to mind (I've dealt with the same issue on my 95 XJ). I ended up swapping out all the sensors (Except the CPS) I would recommend the coil (mine was cracked) and the fuel pressure regulator on the fuel rail. As it's an intermittent problem, pressure testing might not pick it up. At least yours isn't in the tank. (FPR) God bless and stay well.
Yeah. I’m going to investigate the coil further 👍🏼
@@JeepSolid if it ends up being the problem could you do a video on it?
It's worth a shot I would disconnect the negative cable and hold it in the positive cable post but leave the positive connected do that for 30 seconds it resets the ecu. It might think it's still the old crank position. I so it on my remix motor any time I put new sensors
Worth a try 👍🏼
I've seen a bad ground strap to the motor do this. sure seems like an electrical gremlin to me. I'd start by making sure I have a good ground to everything. including the fuel pump.
replace the distributor cap and rotor also the sensor inside the distributor. My 94 jeep 2.5l had the same issue. After replacing this items no more hesitation.
I have the same issue cuz my wire fraded. I took cap off took the rotor off and took the two bolts off on top and now I can’t seem to get tht metal thing off. Any ideas how? I can see the sensor too just need to take that last thing off
Dude this was exactly my problem on my 2015 Wrangler, and no one could figure it out until the check engine light came on and it gave the error code for bad crank sensor. I thought my clutch was going bad!
My 93 had a similar issue and it got worse and worse until I could hardly drive it. I put in a cheap TPS bought online and it fixed it for a few months then went out again. Then I bought a better one from a reputable auto parts store and it hasn’t done that in over a year now.
My guess it’s that same thing with yours.
Could be. Thank you
I have the exact same issue. After extensive research, it really looked like the culprit was the crankshaft position sensor. Also replaced with a cheap part and it also didn't change a thing. Put the original one back.
I will stop trying to find the solution and just wait for your next video(s) 😅
Yes. We’ll get it
Hey Dale, did you find what was the issue?
I love tf outta this man’s channel! Your videos helped me get my 93’ project yj up and running, after being dead for 3 months! Thank you! 🥲🙌
my jeep did that just at a lower rpm and it was the throttle position sensor
Good idea
Gonna grab me some of that super clean. 👍🏻
Also Dale, this could be a dreaded ECM issue. Could you reset the ECU and see if the problem still exists? Discharge the capacitors?
Oh man. Hope it’s not 😬
Only 10 bucks? Oh boy 🤦♂️u gotta use a mopar one ! $120 bucks = reliability🙋🏻♂️
The symptoms are uncannily similar to what my older caddy did when the pcv valve went...
I need to check vacuum 👍🏼
Do them Jeep’s have a EGR valve? I’m not real familiar with those but I love a good diagnostic video. Hope you solve the issue , God bless you and your family?
Like to know where you got a crankshaft position sensor for it Jeep Cherokee for 10 bucks? I just paid $76 at AutoZone? The crankshaft position fixed the issue of my Jeep suddenly while driving but it did nothing for acceleration hesitation which is still an issue that I'm still having. Maybe it will fix this Jeep but does not fix hesitation in my Jeep it just fixed a different problem
Keep at it man . I love my YJ but she has something wrong and I still can't figure it out . She runs like a champ tell you start going up hills then it starts loosing power really bad . And backfires from somewhere in the engine bay any input on this would be great
Sounds like fuel mixture
@@JeepSolid I'll start looking into that in the morning. Thank you so much for what you do you have helped me so much with my jeep already if your right I'll buy you a cup of coffee sometime maybe at that YJ meet up you've talked about .
@@newcaloutdoors505that sounds like somethings getting clogged. I’m new to jeeps but my 00wj has 250k. Skips twice when cool then it’s fine. I think it’s tranny tho cause it sounds like high gear clutch is disengaged intermittently until I let off gas. If I don’t let off gas it will eventually shift with a loud bang from the torque converter (I think) no grinding or metal on metal sound for now. Funds and tools are an issue. Hope your jeeps runnin good 🦆
Well to me sounds like a tps problem or cam shaft sensor low fuel pressure while accelerating also could be the reason its just one of those tricky things
I’m going to look at tps and coil next 👍🏼
I've replaced it on my dad's XJ... hard to reach..lol
Yeah. On the yj, it’s not that bad
Did you end up figuring this out? Having same exact issue, put new injectors, fuel filter from mopar. Want to see if you fixed it some other way before I order a new fuel filter.
Fuel pump**
I've got a 91 autom yj 6 cyl... my crank sensor is attached with only one bolt, and I lost that bolt !!! any idea about that specific bolt ?!
CPS on a 4.0 is one of those things you only ever use MOPAR.
Yeah. It’s aftermarket one made no difference. I think old one was fine
@@JeepSolid I think these things just get air bubbles in the gas line or something.
My 97 XJ has occasionally done this since it was new (yes, I'm the only owner).
I just call it a Jeep thing.
Almost sounds and looks like the distributor advance ( probably mechanical) is ground out or getting stuck as rpm is coming up...could be on the vacuum side if under load...Or the idle air solenoid is malfunctioning.. but the fast Drop in the Tach says to me to check the distributor..
Yes. And I need to check coil
@@JeepSolid yes to the coil, but in my 50yrs, never seen a coil go half bad, either they work or they don't.. and usually it's the primary side that has an open in the winding..
When is the last time you changed the fuel filter ..... could be the start of it failing.
I was wondering if you know how to change the pick up call you in the distributor on a 1987 YJ 4.2 L I can’t seem to figure out how to take out that little pin without damaging anything
TPS sensor or idle air control valve
YES, I would take the Throttle body off & CLEAN EVERYTHING VERY WELL, install new gaskets & O-ring if needed.
Yes. That’s good idea, but already did that..
Mine hesitates sometimes when i first start and drive it. Then it goes away after i drive it for awhile. Could it be the cps?
I have a 92 DJ that has a similar problem new motor still has a problem
Not adj a xj
So, did you get it working and what was the problem?
Is there a CPS relearn procedure for the 4.0?
Would a mass air sensor work?
That year has a Air Charge Temp. Sensor that screws into the intake manifold. Maybe take it out & see how dirty it is.
I’ll check
Mines a rock crawler how can I just bye pass the sensor
I’m having this issue to but it only starts hesitating after driving it for awhile. If anyone has any suggestions on what the problem could be please let me know
Sounds like something is getting HOT then acts up. Could be the coil ? It's not VAPOR LOCKING is it ? When the fuel rail gets hot & boils the fuel in it.
On my 96 XJ, I’ve added aluminum/fiberglass manifold insulation, pipe insulation on the fuel rail, and a thermostat control to the aux fan to alleviate hot start hesitation. It has almost eliminated the problem. Using ethanol-free gas also helps.
A cheap oscilloscope like a hantek will make diagnosing sensors easy.
Oh man! Yes. Been looking at them. Just haven’t pulled the trigger on an order
@@JeepSolid if you do get one skip the software and go straight to an app called HScope if you have an Android. You can run the hantek with your phone and the app design is brilliant.
I had a similar issue that turned out to be crank sensor. Couldn't see it using a multimeter. Would see the 5volt reference go to ground so thought it was good. With the oscilloscope you could see the signal drop out. You can use it to diagnose your TPS which could also cause similar issues. Good luck!
Dale, consider having a temperature or pressure drop performed between the inlet and the outlet of the catalytic converters. They may be starting to get obstructed or maybe a sensor. No diagnostic error reported?
Thanks. I need to look at that
I’m getting to a point where I just want to replace every gahdamn sensor on my jk.
Espanor
the. places I would check. first. look inside. the cap. if it is. sooty. good Chance of a bad. coil. coils do go bad. in strange ways. if there is any question. replace. OT. there are cheep. I would check the. cam. posistion. pickup. those are pricey. and the sender you just. I just do not trust. cheep. that price. was too low. you need to get a better one. the cheep ones just don't live long. have fun. and thank you. C
I think I’ll look at coil next
$110 not $10
China injectors maybe. Put old ones in.
Did the same with the old ones
Need help with 94 jeep yj 2.5 if you could message me
$110 not $10