Problem at idle

[91_towel_on_awd]

ok, first off when i start the car and the engine is cold it idles between 2500 - 3000. Then when it is moving and i take it out of gear it surges at around 2500. As the engine warms up it goes back to normal. But when the engine is warm it idles at 800 and all the lights dim- dash, head lights, dome light, the whipers move slow, and the vent motor slows down. when i press the gas and the rpms go up it returns to normal around 1100. Could it be throtle positioning censor?

 

[mitsugsx95]

The first part sounds like either a messed FIAV or a bad ISC.

As for the second part, check the grounds and the alternator. Is there a CEL on or does the batt. light, coolant, and brake light stay on?

 

[91_towel_on_awd]

what is the FIAV, ISC, and CEL? sorry to sound like a newbie.

 

[mitsugsx95]

FIAV (fast idle air valve)= helps raises rpms when the car is cold

ISC (idle stepper motor)= controls the idle

CEL= check engine light

 

[91_towel_on_awd]

The CEL or any other light have never come on and i have checked all the battery cables. How can i check the FIAV and ISC?

 

[mitsugsx95]

http://www.myzero.com/engine/surge.html

Check that out. Its a good place to start. For the FIAV, i really dont know if theres a way to check it. I just swtiched mine after the surging started at start-up, guessing that the newer FIAV on my 2g sould work better.

 

[91_towel_on_awd]

thanks, thats jsut what i needed.