Cobradwight

He guys im still messing around with this 90 limited xj I bought a few months ago. Its got me a bit boggled since it runs really good but will occasionally hickup on a dead stop take off(wanna stall). I was messing around with it near my house in 4x4 and she stalls alot...maybe 10 times in 15 min. I took out the iac and cleaned it..it actually look pretty new ,possible other owner might of replaced it. Noticed the intake/exhaust bolts were loose so I tightened them up and my high park idle has seemed to be a good range now. Anything else I can do?

Thanks

Cobradwight

I checked the plugs and they look very new. Also checked fuel pressure at idle with it running, Got a steady 39 psi. Is that to low? I remember looking a while back and thought someone said it should be 49 psi? If so possible weak fuel pump?

cruiser54

Fuel pressure is fine. How are the wires, cap, and rotor?

Also, it's a good idea to clean the throttle body bore and both sides of the butterfly with an oxygen sensor safe carb cleaner or throttle body cleaner. Normal maintenance here.

A gummed up throttle body can cause TPS signals to be off and result in stalling.

Cobradwight

Wires and cap are also new....the rotor looks a little old. Ill clean the tb as u mentioned.

CPTslackass

Have you checked the vacuum lines too the grit diff? Does the front diff lock into 4x4 when you shift the lever? Do what cruiser said, then check that out :-)

Cobradwight

What is the grit diff? It goes into 4x4 no prob and works. If u are in 4low crawing speed it stalls alot. If your doing a decent mph its fine. I noticed a hose going into the front differental and it was worn through from front drivshaft rubbing it.

Cobradwight

U think I could also have a possible bad cps?or one on its way out?

Thanks for the help thus far.

cruiser54

No. If I thought it was that, I woulda suggested that first. CPSs are "crank no start", "long crank times", "die no start" kind of things.

Clean the throttle body etc as suggested before going off on rabbit trails with "could it be this"?

You're not gonna find a "silver bullet" cure here. This is gonna require you, as owner of the Jeep, to catch up on maintenance and eliminate known issues wwith the Jeep, to get to a solution, as provided by people with alot of experience with these Jeeps.

weebur

Just make sure that you use Throttle Body Cleaner, not carb cleaner like Gummout, it could damage the finish on the throttle body bore. I clean mine with a soft toothbrush making sure that the inside of the throttle plate is clean too. Wipe the bore down with a clean soft rag until it shines like new. I do this at least once a year.

cruiser54

Actually, there is no finish on the bore of a Renix throttle body. Just good old metal. The important thing is to use an oxygen sensor safe cleaner which I believe all throttle body cleaner is. It will say on the can.

Cobradwight

Ok I will for sure do as u mentioned..got busy with the family yesterday. Ill report back as soon as I get a little free time to mess with it.

weebur

Thanks, I didn't know that, but I wonder if the throttle plate is brass if it has a protective finish to keep it from tarnishing.

cruiser54

Nothing special about the butterfly either. Scour away with reckless abandon.