99 camaro ss high idle...Please help!

[flynlow32]

I purchased a 99 ss camaro and noticed it having a slightly high idle. When its cold it runs 1500 rpms. Once warmed up, it runs 1200 rpms. This is what i have tried:
Tried playing with the set screw on the throttle body. It made no change in idle but cause the throttle to stick everytime i let off the gas. I then returned the settings.

I pulled the IAC sensor off and cleaned it really well. When i unplugged it, the rpms jumped to 2000.

I pulled off the tps and made sure it was clean and the seal was good.

Re installed everything and idle was still high. I tried to spray around and on the vacuum hoses with the car running to see if i could get a surge meaning i had a vacuum leak but had no luck.

Is there any other reason my rpm are so high? It really worries/bothers me.
Thanks in advance for any help.
JEFF

[foff667]

when you played with the set screw on the TB did you ever reset the tps to know what throttle position it should be at?

[flynlow32]

No. How can i do that?
Thanks
Jeff

[bww3588]

No. How can i do that?
Thanks
Jeff

get the idle ajustment where you want it then unhook your neg batt cable and let it sit for a few minutes. make sure it isint touching anything. then hook it back up.

[IRACE2]

Check the pvc hose that goes into the manifold. Mine was leaking and causing high idle.

[dexcool]

I dont think your supposed to touch that set screw man, if you take it to the shop, make sure your mechanic knows you did that so he doesnt chase his own tail around trying to figure out his scan tool reading issues.

[dexcool]

Idle Learn Procedure

Anytime the powertrain control module (PCM) or the battery is disconnected, the PCM loses power, or the PCM is reprogrammed, the PCMs learned idle position is lost. The engine idle is unstable when the learned idle position is lost.

Perform the following procedure in order to return the learned idle to the correct position:

Automatic Transmission

1. Turn OFF the ignition.
2. Restore the PCM battery feed.
3. Turn OFF the A/C controls.
4. Set the parking brake and block the drive wheels.
5. Start the engine.
6. Ensure that the engine coolant temperature is more than 80°C (176°F).
7. Shift the transmission into Drive.
8. Allow the engine to idle for 5 minutes.
9. Shift the transmission into Park.
10. Allow the engine to idle for 5 minutes.
11. Turn OFF the engine for 30 seconds.

Manual Transmission

1. Turn OFF the ignition.
2. Restore the PCM battery feed.
3. Turn OFF the A/C controls.
4. Set the parking brake and block the drive wheels.
5. Place the transmission in Neutral.
6. Start the engine.
7. Ensure that the engine coolant temperature is more than 80°C (176°F).
8. Allow the engine to idle for 5 minutes.
9. Turn OFF the engine for 30 seconds.

[TwistedSS]

I'd check to make sure the EGR hose leading into the top of the manifold isn't in there incorrectly. There is an o-ring on the EGR hose that can get cut or incorrectly seated and would cause the engine to idle higher than normal