Thread: Cold idle fine..when warm, it's high?

Yo,

Having a strange idle issue I've yet to figure out, but my situation is a little unique so it may help narrow the issue down.

When I start the car cold, the idle will be 'normal' like it should around 1500 RPM. It will slowly drop like normal until operating temperature. It will drop to 1000-1100 RPM when operating temp. The odd thing is, as soon as the car warms up the idle will slowly start to creep back up. Idle will be around 1200-1400 RPM when warm.

If I turn the car off hot and start it let's say 15 minutes later, the car will idle fine(around 1k RPM) UNTIL I give it some gas and then idle will be around 1200 and then as I drive it and stop to idle, it will stay at 1200-1400.

My idle screw on the IACV-AAC is all the way down. I have tried resetting base idle quite a few times in Consult without success. I recently cleaned the IACV-AAC. I can see through Consult that the IACV seems to be working correctly. I can see it slowly decrease voltage(or whatever) as the car gets warmer and it stays low even when warm and when I'm having these issues.

Any ideas what is causing my idle issues? Anyone experience similar problems?

-G

I have something kind of like that, my car warms up fine but sometimes after driving it on the highway I get off the ramp and the idle stays at 1500, I used to be able to turn the car off and it would go back to normal but now no matter how many times I shut it off it stays at 1500. Other times the cold idle never drops and then after starting to drive it goes to 1500 and stays there. My engine is also a ve if that matters, I have 3 iacv that I have used on this engine but the same problem is still there. I have also noticed it uses more fuel while driving when it is stuck at 1500 idle, and while accelerating heavy it blows black smoke out the tailpipe.

Mike22487, I think I have the same issue, but on my OBD1 VE. Do this, turn off the car, but don't take the key out (radio listening mode), listen to the relay click, then start the car. This returns my idle to normal every time.

What happens for me is, ECU forgets the closed throttle TPS V, and thinks the throttle is open thus idles higher. Doing that dance makes it remember the TPS voltage again and all goes well.

There are a couple other things you can check, make sure your throttle body is clear of nastiness (i.e. carbon ring around the inlet) the aac valve (i think thats what is called.) behind the intake manifold. check for vacuum leaks. if everything checks out, run some GM top engine cleaner!

TB is clean. There's a small vacuum leak at the IM gasket which will be fixed soon. Regarding the AICV(behind IM), that could be the issue but it's strange that it seems to be working on cold start but kinda reverses itself upon warming up if that is the problem.

-G

Sounds like that vacuum leak, let us know what happens after its fixed

lol...mine is complete opp..i recently grounded the maf and hooked up 1 fan to directly so it comes on as soon as the key is turned on...now when i start it..it stays at like 1500 rpm and once i drive it for like 15 min or so it goes to 900-1000...and its been burning ALOT of gas too...i also got the temp sending unit and temp sensor also...still no guage movement...no idea!!! help would be nice...thanx

i did a det swap in mine and i dont have the temp guage working but someone told me that it has to be from a usdm sr20 cus the usdm wont read the japanese ones. but if you have changed it before and no reading from your guage then i would check your cluster.

I'm curious if you find/fix your issue Lucas. Working with some local guys on a Chump Car, and I've got a similar issue. Idle screw all of the way in, and idle is still ~200 rpm to high when using Conzult. They/we have a very slight vacuum leak that will get addressed also, so I'm hoping that is the issue.

Good luck

Josh

I have a new symptom..

When the A/C is on and i declutch, the car will a lot of times drop RPMs so low that the car will just turn off. This is pretty annoying as I am having to tap the gas each time I declutch to keep the car from stalling. Once I tap the gas once, the car will idle fine. It's only after the initial declutch that the RPMs will drop a lot.

Any ideas?

Thanks!
-G