My 1991 accord 2.2 ltr auto starts fine but after it gets up to temp it surges between 800-1600 rpm in park.I have removed and cleaned the IACV and the problem persists.The car has 119000 miles and all else seems to work well.The only other problem is the temp gauge shows full hot even on cold startup.When I unplug the sending unit it goes down to cold.I suspect the sending unit is bad.Coolant level is normal.The surging problem is also compounded when any other electrical accessories are turned on.especially the heater fan.Any Ideas would be appreciated.

 

Cleaning and tightening the FITV may fix your problem.

See the FITV thread in the DIY section.

 

FITV post in the DIY secton - not inside the manuals thread.

 

Thanks for the correction. Couldn't find it in the manuals thread.