Engine "motorboating" at idle

1991 ACURA INTEGRA
265,000 MILES • 4 CYL • FWD • MANUAL
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RIKMIC
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The cold start idle is around 1400 RPM. With warmup the idle steadily "motorboats" between about 1050-1600/1700 RPM. Driving perfomance is excellent-the problem is just at idle. I have located the idle adjustment screw and it is screwed all the way in. As I adjust it out, the RPMs become higher by a factor of 400-500 RPMS at both ends of the range. A possibly related problem-in hotter weather the engine will not start after short stops, i.e. to run into a convenience store, etc. It seems to need to cool down a bit first. Maybe related, maybe not
Dec 15, 2010 at 7:43 PM
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MHPAUTOS
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There are a few things to be checking here, make sure that there are no vacuum leaks, clean the IAC and the throttle plate, check ignition timing, check for any unresolved fault codes with a scan, start here.

mark (mhpautos)
Jan 24, 2017 at 7:07 PM
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