I have had a problem with my engine not returning to idle when I let off the gas. I've been told to clean the throttle body and did and had no effect. Next I was told to clean the IACV and I did and still the problem exists. What's next?

Thanks.

 

Adjust your default idle stop screw.

1)Have the engine up to operating temp.
2)While the car is off, disconnect the TPS.
3) Start the car and adjust the idle stop screw on the throttle body until the idle is around 700 RPM's.
4)Turn the car off and reconnect the TPS sensor
5)Start the car and see where your idle is at. If it's to high, adjust the idle speed by turning the IACV bypass screw located in the hose the connect the IACV to your intake. It's usually a larger phillips head covered with a plastic cap.

 

Are you sure? I did neglect to mention that it will return to idle if I hit the gas pedal. I've checked the cable and it appears to be free. This is a periodic problem that seems to be more common when the engine is warmed up. What I mean by periodic is that it occurs every other time or less. Sometimes it does return to idle with no problem.

 

Just verify that it does idle at the right speed with the TPS disconnected. If it doesn't, adjust it.

 

If hitting the gas fixes the problem, your throttle cable may be sticking. You can spray some lubricant (WD40) down into the cable if you need to.