Car idles fine on cold start, but once warmed up idles high?

[97GSeX]

So like the title states, when i start my car up on cold starts it idles just fine at about 1100-1200 RPMs. But once it starts warming up the RPMs slowly begin to climb, and once its up to opperating temp. the RPMs are all the way up to 1500RPMs. Car runs and drives fine, so I'm not too sure what it is thats going on. Any idea's of what this might be?

 

[gtbread77]

2G BISS Adjustment Try this see if it helps

 

[2GFWDbeast]

Sounds like your iac is little out of wack. Does it idle surge at all? I would take it out and clean it. Sometimes have carbon build up on them.

 

[chuckstsi]

Any CEL's?

 

[97GSeX]

2G BISS Adjustment Try this see if it helps

This helped a little bit, but still idles around 1400RPMs, and no there are no CELs. And there isn't any surges or anything. But I might try cleaning the IAC

 

[chuckstsi]

Just my 2 cents here. I dont believe the IAC is affected by engine temp as far as I understand. Possibly a sensor telling the ecm that the engine is at a different temperature than it is?

 

[2GFWDbeast]

also try coolant temp sensor forgot all about that haha

 

[Alan11]

Any vacuum leaks...or Tps... that's all i can think of right now..

 

[Absit]

Check your throttle cable adjustment. When the car gets hot the sleeve shrinks, tightening the cable.
DSM engineering yo.

 

[97ebaygst]

Have you done a boost leak test?

 

[97GSeX]

Have you done a boost leak test?

No boost leak test yet, I need to get my hands on a compressor. But as for the vaccum leak, on the intake manifold it has the letters PEA across and the one labeled P was making a whistle sound and sucking in air so I plugged it with another vaccum line plug like the others. Is that how its supposed to be? Or does it need to be open? And another thing I noticed, my A/F ratio went down to about 11.0 from 14.5-15.0 (on my A/F gauge) at idle..not sure if any of this helps at all but thought I'd give it a try.
Thanks

 

[Absit]

Were you in closed loop when the AFR dropped? Did you check your throttle cable?

 

[97GSeX]

Were you in closed loop when the AFR dropped? Did you check your throttle cable?

I was messing around with my filter/piping when it happened, I took it off to see if a newer one would fit but it didn't so I put the old one back on and started it back up and thats when the RPMs went up and the A/F went down. But no I havn't checked the throttle cable yet.

 

[blkgst97]

I would also suggest the throttle cable.

 

[beantown_dsm]

I had this same problem and tried a bunch of things that all helped a little bit. IAC, tightened the cable, took apart the throttle body and cleaned it, checked for vacuum leaks, changed coolant temp sensor, thermostat, but the thing that made the biggest difference was my upstream o2 sensor. Whoever had the car before me put a universal o2 sensor (which never work by the way) and after replacing it my idle has been fine. maybe you dont have a universal o2 but its just something to think about.

 

[97GSeX]

Got it! I messed around with the MAF sensor a little bit and turned on my car and it idles just fine. Must have just been a loose connection, thank god it was nothing worse! Thanks for the effort from you guys, I appriciate it.

 

[92AWDHX40]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)
Try this site.

 

[bigdoug3022]

I had a problem like this ended up being a bad pcv valve just a thought

 

[90tsiawdturbo]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)
Try this site.

that is GREAT info....your a hero for posting that