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Idle Question.... Please Read 700 1990

Ummm, I think you've got an LH 2.4 system, but you guys are talking like it's LH 2.2. Unlike earlier designs, the IAC is spring loaded to stay closed, has only two contacts (one is ground) and is pulsed to open to the governed rpm based on input from the crank position (rpm) sensor, the block temp sensor and the A/C compressor, but only when the throttle position sensor switch says your foot is off the gas and the throttle plate is closed. There is no base idle adjustment on the LH 2.4 system other than making sure the throttle body is properly adjusted (especially the throttle plate stop screw and the throttle position sensor switch rotational setting). If there is any chance these have been touched or any of the throttle linkage has been tinkered with then recheck the settings (see the FAQ and/or search for articles)

Now you said you had a leak at the flame trap. That's a vacuum leak of unmetered air intake and you need to deal with that before getting too excited about a bad IAC. No need to spend money on something that ain't broke.

You should remove and thoroughly clean the throttle body (see the FAQ) -this is a normal maintenance item that is often ignored and is the source of many idle related problems. You should flush the IAC valve clean, twist it rapidly to work it in, dry it before re-installing. Finish off by running the LH 2.4 diagnostic tests described in the FAQ (OBD section) to check that the throttle position sensor is working properly plus do the one that exercises the solenoids including the injectors and the IAC valve. If the engien has problems maintaining idle when the A/C is switched on then there are diagnostics for that too.
--
Dave -own 940's, prev 740/240/140/120's & quasi-expert only on a good day






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