I have a 1990 IL6 4.0 cherokee auto trans.

From a cold start there is no problem with it starting but after driving somewhere like a gas station getting a drink and then trying to start it up again sometimes the throttle will stay wide open and shoot up to 3000rpm.

other times it will start up shutter and shake and then stall out unless i keep my foot on the pedal and keep the rpms up.

I replaced the cps and i'm wondering if the throttle body needs cleaned out, the spark plugs need to be replaced or maybe the gapping is wrong, or the tps sensor needs replaced.

Thanks in advance.

 

bump

 

i would clean the throttle body check and the plugs if real dirty replace them if you gonna replace plugs go ahead and replace wires cap and button but sounds like you need a tune up and the computer is advancing th timing to let it run

 

If you are going to check your plugs just go ahead and change them. They are not expensive. I would check the Throttle body and the injectors.

 

Clean your idle air controller, be careful. it's located on the throttle body by the tps if i remember correctly.

 

x2, Mine likes to do the same thing. Sometimes it starts fine other times it will jump up to 3000 RPM and sit there for a couple seconds.

I took the IAC out and cleaned it up real good using some throttle body cleaner. It didnt fix it completely but it doesn't seem to have weird start ups as much as it used to.

If i had the money id buy a new IAC but if i recall autozone wanted somewhere around 40-60$

):

 

alright i'm going to clean the TB and then double check the plugs to make sure everything is in order there and report back

 

I replaced the spark plugs, wires, distributer cap and rotor and cleaned the TB and IAC there was a lot of carbon build up on both. So far I havent had a rpm spike but i did get a really rough start still.

Started on a cold start drove about 15 minutes went into home depot for about 15 minutes came back out and it started but it shook and shuttered like it was about to stall but continue to run.

Looks like something else still needs to be done.

 

any ideas?