91 Cherokee Laredo dies when warm

[gr8owl69]

Hi I am new to this forum and would greatly appreciate any help or advice with this problem as I am about to push my Jeep into a lake, reluctantly.

I have a '91 Jeep Cherokee Laredo 4wd 6cyl 4.0L. When I drive my Jeep it will start great, idle fine, and act perfectly. However after about 15-20 minutes of driving, or at least when the engine warms up the car will start to sputter as if I am on a rodeo bull. Then the engine will just die, as if I have turned the key off. Sometimes I can let the car roll for a few seconds and the car will start back up, but I need to keep constant on the accelerator or it will die again. Then when I go to restart the pain in the *** it will only crank. I usually can wait a few mins and it will start again but will only drive momentarily. Also some times before the engine warms up and does the dying thing, if I hit like a big pothole or speed bump, it will start to jerk again and sometimes will die.

I have so far replaced the spark plugs(I broke one off in the engine wall and had lots of fun paying a mechanic to fix that one), wires, distributor cap & rotor, CPS (Pain in the butt to change I might add), Fuel filter, checked fuses under the steering column, and I have read all threads with no luck to finding my problem. I even tried a suggestion to keep my cruise control on the "off" position. I have had a nightmare with my baby and it only has 90,000 miles on her, and her body is mint so I can't give up.

Again any suggestions would be great. Thanks in advance for any help anyone can offer.

[gr8owl69]

I forgot to mention that I have to wait several hours until the car is cold. Then I can drive again for about 15-20 mins.

[JDPascal]

one thing to check might be the suction screen in the fuel tank or the vent in the fuel cap. both will starve the engine for fuel.

when it stalls, do you still have spark??

If you do, then it is likely a fuel problem......

JD

[Saudade]

As JD suggests, you need to determine if it's a fuel or electrical problem.

Will it die if you let it idle for the 15-20 minutes or must you drive it around?

If electrical, there is also the Throttle Position Sensor. You can check it using this: http://tinyurl.com/4z936

Check it cold, the run the engine until it dies and check again. If it checks OK, then rule it out.

You can also remove the gas cap after it dies to see if it's a fuel vent problem.

[gr8owl69]

Thanks all for your replys, I will check to see if there is spark and get back.

[rotorfloat]

owl, just solved similar problem, performance seriously diminished when engine warmed....check EGR system...that was my problem. Good luck.

[Dale Aeppli]

Originally Posted by gr8owl69

Hi I am new to this forum and would greatly appreciate any help or advice with this problem as I am about to push my Jeep into a lake, reluctantly.

I have a '91 Jeep Cherokee Laredo 4wd 6cyl 4.0L. When I drive my Jeep it will start great, idle fine, and act perfectly. However after about 15-20 minutes of driving, or at least when the engine warms up the car will start to sputter as if I am on a rodeo bull. Then the engine will just die, as if I have turned the key off. Sometimes I can let the car roll for a few seconds and the car will start back up, but I need to keep constant on the accelerator or it will die again. Then when I go to restart the pain in the *** it will only crank. I usually can wait a few mins and it will start again but will only drive momentarily. Also some times before the engine warms up and does the dying thing, if I hit like a big pothole or speed bump, it will start to jerk again and sometimes will die.

I have so far replaced the spark plugs(I broke one off in the engine wall and had lots of fun paying a mechanic to fix that one), wires, distributor cap & rotor, CPS (Pain in the butt to change I might add), Fuel filter, checked fuses under the steering column, and I have read all threads with no luck to finding my problem. I even tried a suggestion to keep my cruise control on the "off" position. I have had a nightmare with my baby and it only has 90,000 miles on her, and her body is mint so I can't give up.

Again any suggestions would be great. Thanks in advance for any help anyone can offer.

HI, IF IT STARTS ACTING UP AFTER IT GETS WARMED UP COULD BE THE OXYGEN SENSOR, SINCE IT ACTS UP THEN TAKES THAT LONG FOR OXYGEN SENSOR TO REACT. EGR WOULD ACT UP RIGHT AWAY AT IDLE ALSO CHECK WIRES DOWN AT SENSOR , THAT THEY'RE AWAY FROM HEAT HOPE THIS HELPS DALE [email protected]

[cherokee_guy82]

have '92 laredo same prob, ended up being the coil... casing had crack in it and heat caused it to open farther and short out until cooled again