Resolved Help! Idle Problem

[JR2G]

So my car started to idle the rpms keep going up and down around to 0-2000rpm but when i turn on the a/c it stops the idling and when i unplug the iac it stays at 1000rpm, i already replace iac sensor but it still does it and i also replace the throttle sensor. This started ever since my car over heated, i did not notice it was over heating because it was at night and i didn't see the smoke until i saw the speedometer basically the thermostat didn't work so i replace it and the radiator because it was leaking. when i fixed it every thing work fine after couple of days the idling started, so now i can't figure what's wrong with it. also whenever i turn on the car it sounds rough.

 

[Supra Mario]

Have you performed a boost leak test?

 

[JR2G]

Have you performed a boost leak test?

At the moment is not turbo

 

[GSXgreen]

A compression test will help determine if the engine is sick or healthy. That's a good place to start IMO.

 

[Dsmkauai]

So what kind of car and engine? Any oil in coolant or vise versa? Also agree a compression test since it over heated. Can't really say much more till we know what motor

 

[GSXgreen]

Your cylinder pressers should be higher in a n/t compared to a stock turbo engine. The four cylinders should also be close to the same, within 5 or 10psi. Let us know what they are. Anything above 120 should still run at least.

 

[94laserawd]

Check for vacuum leaks and compression test.

 

[JR2G]

Thanks for the help everyone but i found the problem the coolant temperature sensor and the connector did not work. i already replace them and now it's running fine.

 

[GSXgreen]

Glad you found the problem and thanks for letting us know.