Ive been having an occasional very slight misfire lately but the jeep has still been running well for the most part. went wheeling yesterday and out of nowhere my rpms drop to like 200, and it started misfiring BAD, and then just died. cranked it up again and it didnt wanna start til i gave it a ton of gas, revving it way up seemed to stop the issue.

I thought maybe it as heat soak so shut it off, came back 10 mins later and then same story, wanted to die until i was able to rev it hard. But i don't think it was heat soak bc it happened on the way home, this time going 70 on the highway with the heater on. it seems to wanna die if i let it sit at idle as well. any ideas?

I'm confused because it didn't wanna start after shutting it off and letting it cool off that one time, but after that letting it sit for a while actually seemed to fix it, I thought it was due to heat while on the trails, but then it happened on the highway at low temp... very random....

 

anybody? ....crickets....

 

Year, motor, trans etc?

Ignition coil/coil pack?
Cap and rotor
Spark plug wires in good shape?
Spark plugs gapped and in good shape?
Wrap the fuel rail and injectors in insulation wrap to help with heat soak

 

Heat soak usually needs more than 10 mins in my experience. It's happened to me after long road trips and then letting the car sit for 20-30 minutes. I would say check your battery connections too. I had a recent experience where my car was sputtering and dying out of nowhere unless I really gave it some gas, and it turned out it was simply a loose battery terminal.

 

96 4.0 HO, AW4. everything else you just asked about has been recently replaced. but if this was heat soak i don't think it would happen on the highway with my motor at 180 degress

 

ECU connections?

 

Any CEL?

Check the grounds.

 

i replaced the cps today and now it doesnt randomly die anymore. but is still throwing a check engine light for a misfire in cylinder 1.