Ck9887

I have a 98 GT with 112k on the clock. Only mods are PI intake and dumped exhaust with X pipe.

Well lately its been giving me some problems. When I first start it the rpms's will jump up and down and then stall. If i give it some gas its fine but as soon as i let off the gas it will drop below 500rpms and then jump back up and down, stalling occasionaly.

The first time this happened about a week ago, I didnt think anything of it becuase I just tapped the throttle and it went to normal. It seems its after the car has been sitting for 6-7 hrs is when it gives me the problem.

Whats weird though is it doesnt happen in the morning when I start it up to go to school. But when I start it up after school it does it. It will continue to have the problem as soon as I let off the gas and when I clutch it to shift, the Rpms fall suddenly, until i get it in gear and let out the clutch.

After a good 15 minutes of driving, the problem goes away and is fine


Do you guys have any idea what it could be? I do need new spark plugs and wires, they are in pretty rough shape??? Im sure my job as a pizza delivery driver isnt helping the condition. [sm=badidea.gif]

Any help would be good. Thanks

Dan04COBRA

It could be a couple things, your IAC (idle air controller) valve is on it's way out or your Mass air Meter is collecting moisture somehow. I had this problem with my GM car, everytime I let her sit for a couple hours moisture would build up in the plug and idle & drive funny until it dried out.

Also, bad fuel pumps on the way out give cold starting problems and sometimes no other symptoms. But I'd look at the first 2 things I mentioned before you even worry about your fuel pump.