Is it normal that my rpm would be around 1600-1800 at startup while warming up in park. Then I drop into gear and it goes to 1000 or below? It has done this for some time. I did just replace valve cover gasket and spark plug wires, but I don't think that is the cause of this. I also think it did this before the extreme cold temps we have here in GA, below freezing, which is cold for us!

TIA

 

Depends on what year. For some it is normal when the engine is cold.

Idle speed when warm should be around 800ish.

If the engine is warm at startup the idle speed should not rev up as when cold.

 

Thanks for the info. The car is a 98 camry LE, 4 cylinder. This has been going on for at least the last 6 months, primarily always on a cold start, not when I have been running around and hop back in the car. I will start the ignition, then it is instantly at 1000 rpm, 10 sec later 1200, 10 sec later 1400, 10 sec later 1600 and then it tapers off at about 1800 and will stay there about 2 minutes and will slowly come down and finally idle at 1000 after about 3-5 minutes. Any thoughts on where to start?

 

There is no manual idle speed adjustment.

The Intake Air Control (IAC) valve controls idle by adjusting the amount of air bypassed around the throttle valve. It is attached to the throttle body and plumbed into the coolant system. The valve has an electric motor that responds to signals from the computer.

The valve can become dirty with grime. The internet should have posts on how to clean the valve.

Sometimes the engine coolant temperature sensor for the computer can go bad. The coolant system also has sensors for the dash gauge and to control the radiator fans thus you need to find the right one. You can check the sensor using a VOM to check ohm resistance.

Might also check to make sure the throttle plate anti-stick dash pot is fully retracting. This is a vacuum controlled dash pot. When the engine is off it pushes the throttle pulley (and throttle plate) slightly preventing the plate from sticking in the throttle bore.

The dash pot has nothing to do with engine idle and should be "disengaged" when the engine is running.

The Autozone website should have technical data on this car and checking the various parts and sensors.