Sensor question

[da9r00d]

i have a 1988 Jeep 4.0L. it shuts off when its hot (driving for a long time), when i start it back up it fires right up but them turns off. when i start it up i can rev it for about a 1 sec, then it just dies out. i seems like the fuel or spark just stops. i have already changed the Distributor (with a used one) and changed the sensor inside the transmission bell housing (New one). could it be the TPS sensor or the sensor next to the TPS? or has anyone had this problem?

Also sometimes the Jeep misfires, it still runs but it runs like crap. sometimes it runs great, dont know whats going on.

[Mudderoy]

i have a 1988 Jeep 4.0L. it shuts off when its hot (driving for a long time), when i start it back up it fires right up but them turns off. when i start it up i can rev it for about a 1 sec, then it just dies out. i seems like the fuel or spark just stops. i have already changed the Distributor (with a used one) and changed the sensor inside the transmission bell housing (New one). could it be the TPS sensor or the sensor next to the TPS? or has anyone had this problem?

Also sometimes the Jeep misfires, it still runs but it runs like crap. sometimes it runs great, dont know whats going on.

We had a response to your post from our Facebook page...


Chris Ball - Its the sensor in inside the dist.. ive seen it on grands with the 4.0! take a look under the dis cap

[4.3LXJ]

I would also check the fuel pressure while running. It might not be getting enough fuel passing the filter on the frame rail. Since it will start, but not run long I am guessing it is running out of fuel at the proper pressure for the injectors. A fuel filter might end up being a cheap fix.

[xj4life2]

Sounds like the IAC to me its the one next to the TPS sounds stuck open. I had the same issue a few weeks back

[da9r00d]

im getting a misfire when i have the gas pressed only a little bit, does not matter what RPM, but if i hold the gas down it revs fine. i have everything new on the ignition and new injectors. new CKS and CPS sensors. gonna try and change the 02 sensor. and the intake/exhaust gasket.

[prerunner1982]

We had a response to your post from our Facebook page...

That's good stuff right there.

[default83]

coil could be getting hot and cutting out. might be worth checking out.

used to happen all the time on my old camaro, the coil would get hot and it would just cut off.

[da9r00d]

its a new coil, i switched it out to an MSD box/Coil

[Punisher]

It sounds that your having the same problem I had a while ago and come to find out it was a crack flywheel that was giving the wrong timing for the plugs to fire and I had it replaced then it ran great and after about a year it did it again but this time it wouldnt start and so I pulled the motor just to do a re-ring kit cause of no compresstion on #3 and discovered the reason it wasnt starting is cause the flrwheel cracked again like the old one did... So if nothing else work try looking for a cracked flywheel on your jeep..

[da9r00d]

Still need help...... New knock sensor and new coolant sensor, NO CHANGE still misfires.

I think im gonna drive it off a cliff... but it would prob still be drivable after that.

im gonna take it into a shop and let them deal with it, ive already spend $1000 in sensors and ignition parts with no change

[Thomass]

i have a 1988 Jeep 4.0L. it shuts off when its hot (driving for a long time), when i start it back up it fires right up but them turns off. when i start it up i can rev it for about a 1 sec, then it just dies out.

So i do understand that when the engine is cold the error doesn't occur, just only when it is hot....

in this case you should check the vacuum line from the map censor to the side of the throttle body, a special the rubber part where the line goes in the throttle body.
this rubber part will sometimes just get destroyed by fuel fumes and heat and causes by an hot engine a place where vacuum might leak.
also check this tubing for cracks or nicks.
and do check your map censor on functioning.
because what you describe, (after replacing so many censors) it might be just a vacuum error.
without this connection to the map censor, the engine will just stop, misfire,
and it seems that it want to start but wont.

[pvt.tadpolxj]

Try cranking a few time's and then put into nuetral and wiggle shifter around. if that work's try rebuilding your NSS. switch. there is a real good write in here from Melissa....