adjust idle speed

[turbobrick]

Ford Escort LX '95, 1.9L engine: The engine idle speed is quite high when the engine is cold (about 1500 rpm). Is that normal and if not how do i adjust the engine idle speed during the warm up phase? Once the engine is warm, the idle speed dops to 800 rpm.

[denisond3]

You cant adjust the idle speed. The computer tells the idle air control valve to move "more open or more closed" to control it. Its possible you have a sticking idle air control valve; or something else wrong. It could be a throttle position sensor that is not indicating 'shut throttle'. Perhaps a bad coolant temp sensor could cause this problem, I dont know. Our 92 seems to idle at 1200-1400 when it is not warmed up, so running at 1500 isnt tooo bad. Also check for leaking hoses at the PCV valve connection to the intake manifold.
I would start by squirting some TBI cleaner into the idle air control vavle inlet. On our Escort you would have to remove the large rubber air inlet to do this, and the engine wont run until that is replaced. On some other cars you can reach the inlet aperture for the i.a.c.v with the engine running, and repeatedly squirt the cleaner/solvent into it as the engine warms up. Not so easy on an Escort though.