Radi

The Idle Air Control valve. It's a small air valve operated by a stepper motor that bypasses air around the throttle butterfly. It allows the ECU to control engine idle.

1eatbunn1es

It is a 1992 so no renix system. If there is a guide to all of the grounds though I will definitely do that, as it cannot hurt at this point. There doesn't seem to be any issues with the map sensor vacuum lines, I replaced a lot of the vacuum lines present on the jeep. I checked fuel pressure when I bought it last year, but I will check it again.

No arching on the plugs or wires. They are actually new with less than 1000 miles on them.

I don't know of anybody close to me that has a coil I can swap in to test it. I hate throwing money at guesses too...

I cleaned out the IAC valve and throttle body. With no change in the jeeps behaviour.

1eatbunn1es

Today I replaced a ground wire and cleaned up all the others that showed good resistance.

Still jerking violently, but not very often. Probably a couple times during a 5 minute driving period. Sometimes several in a row, other times I can go several miles before it jerks.

1eatbunn1es

I tested my fuel pressure today and it was 30 psi with key on engine off, once the jeep was started it was 35 psi. A bit low according to my repair manual which says it should be 39-41. What should I do now? It has a new fuel filter.

ZINGGG

Would you happen to know what brand fuel pump it has on it?

Drewjharper1900

Looks like fuel pump needs replacing. Stay away from airtex

1eatbunn1es

I do not know the brand of the fuel pump. I just found out that I am supposed to take that vacuum line off of the regulator before testing pressure. If so, I have to test again to get accurate results correct?

memasmuffn

$500 1998 Cherokee Sport. Had the same problem. Some times ran real good. other times it bogged out, lost rpm's and didn't want to go. After it was done taking its fit it would run like a champ. tried distributor, no change..Tried TPS. No change. Next a New complete exhaust, catalytic convertor, cat back,upstream and downstream o2 sensors. Thought that did it...but NOOOO!..Started getting worse. I took it to work one day and barely made it up the hill... the guys told me to pull it into the warehouse garage..they opened the hood and with it running sprayed gummout in front of the manifold gasket and low and behold it stalled right out! BAD MANIFOLD GASKETS...took it home & my son and I tackled the job...Replaced manifold and valve cover gaskets...took as about a whole day. Also replaced the power steering lines while we were in there...Not a one problem since. Dont know if this will help you.But that gummout trick is worth a try.

memasmuffn

If you have fuel at the fuel rail your pump is most likely not the problem

1eatbunn1es

I don't think it is the manifold gasket, as it is a brand new gasket seated properly. I just replaced the exhaust manifold.