Guest Brad Gales Posted July 31, 2000 Share Posted July 31, 2000 My 88 has recently developed an intermittent high idle condition (1400 RPM in Park) when restarted after reaching normal operating temperature. In diagnotic mode, the temperature and throttle Position sensors register within tollerance and I just replaced the ECM, thinking it may have an intermittent problem. Any suggestions for possible cause would be appreciated. Link to comment Share on other sites More sharing options...
Guest Posted August 1, 2000 Share Posted August 1, 2000 What does your IAC read at idle? It's reading ED22 on my '90. When you start the car, the engine should idle up for a few seconds and slowly drop back. It's possible the IAC is sticking partially open.<P>------------------<BR>Hal, btk@vbe.com Link to comment Share on other sites More sharing options...
Guest Brad Gales Posted August 2, 2000 Share Posted August 2, 2000 2seater,<P>I think you found the problem. In park at 1200 rpm, IAC reads 52. When at 750 IAC reads 39. I removed the IAC, cleaned and adjusted it, and now the reading at 650 rpms in park is about 10. Thanks for your help! <P>Brad Link to comment Share on other sites More sharing options...
Guest Brad Gales Posted October 5, 2000 Share Posted October 5, 2000 I cleaned and then replaced the IAC, which initially appeared to resolve the problem. However, my problem has returned. The engine goes to high idle (1300 rpm neutral, 1000 drive) if restarted once reaching operating temperature. The IAC is not in the correct position, but there must be some other sensor causing the IAC to go high. Any suggestions would be welcome. Link to comment Share on other sites More sharing options...
Guest Posted October 6, 2000 Share Posted October 6, 2000 Check to be sure the throttle blade is closing all the way. The stop screw is located where the lever for the transmission kick down cable is attached. If it doesn't touch the end of the screw, something (carbon maybe) is holding it open slightly. If I remember correctly, it is normal for the IAC to back out slightly when the engine is stopped to give enough air for a restart. It should idle down very shortly thereafter if the engine is warm. You might try cycling the IAC manually a few times by using the overides in the diagnostic mode. You can force it open and closed with the overide mode. It may still be sticky or defective. I am not sure if there is any particular sensor that controls idle speed except the ECM uses inputs based on load, temperature etc... to command the IAC.<P>------------------<BR>Hal, btk@vbe.com Link to comment Share on other sites More sharing options...
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