Very Low Idle and Stalling

[Kprime911]

hello
i recently started having really low idle with idle surge like around 400 rpm to 600 rpm and the car will stall. When i start the car when its cold it idles at high at like 2k rpm then now goes down to about 500rpm after the car warms up. Also now when i stall and i try to start it up again right away it will just stall the second the car starts up again and the only way to keep it from stalling right away is to just give it gas the second the car starts again. the car drives fine other than the stalling.

thanks

 

[ddavisaf]

Check for Boost Leaks.
Also test your ISC.

 

[JCMDSM]

Make sure your BISS is still there as well.--Jon

 

[Kprime911]

ok i checked my isc and it was bad so i replaced it but now the second i start the car cold the rpms shoot to 2.5k - 3k for like 6 seconds then drop to 2k then after about 3-4 mins drop to 750rpm like normal. also happens when i start the car warm except after it shoots up to 2.5k-3k for like 6 seconds it just drops straight down to 750rpm. Oh and BISS screw is still in the there.

 

[Kloopofadown]

That is your Fast Idle Air Valve. The wax pellet inside it will melt and cause the RPMs to drop down to normal.

 

[femmeDSM]

^^ What he said.
To rephrase: what you're describing is normal on a cold startup.

 

[Kprime911]

it never shot the rpms that high very quickly before on a cold startup...but if you guys say its alright then im not worried.

thanks

 

[femmeDSM]

it never shot the rpms that high very quickly before on a cold startup...but if you guys say its alright then im not worried.

thanks

Yeah, that's what the FIAV is for.

Obviously, though, if anything on your car seems different than what you're used to, you should check it out. Things that could cause a high/unstable idle are discussed at length here:
http://www.dsm.org/how-tos/tttt/tttt3.html

But what you're describing does seem pretty normal to me, especially since you're up in Michigan.

 

[kraka]

My car has basically the exact same symptons...Starts up very cold and shoots straight to 2.5k+ but then quickly down to 2k....Altho, after a minute or 2 of 2k idle, it will decide to stall and kill the engine, and keep wanting to do this until you have your foor pegged on the pedal trying to keep it alive...

The car has been sitting in the garage for 3 weeks, starting up only every few days or more...Like I said, the car runs pretty crappy with the 2k idle, and I haven't been able to drive it yet b/c it's not registered or insured yet...

I can't really leave the car by itself at idle for about 2minutes, and then it will situate it's self at 1.5k-2k steady....I also haven't had the chance to leave the car to warm up, b/c I have to keep it inside the garage, and the gases build up pretty quick and it's hard to breathe, of course with the garage door open....

----This does sound like a normal cold start up right?? I really don't feel like replacing an expensive part right now, I just got cheated $200 and spent a shitload on mods in the last month...

 

[femmeDSM]

Haha, your car sounds like mine a few months ago (what with the "only being able to start it in the garage" business )

What you're describing seems SEMI-normal. I assume you have an aftermarket boost/vac gauge? Are your vacuum readings normal? You might have a small vacuum leak.

Have you disconnected your battery recently by chance? Every time I need to do this, and reset the ECU, the car is confused for a few days and acts like this. It eventually settles down, though.