My 89 carburated Accord will intermittently remain in fast idle (1500 rpm) even though the enging has reached operating temperature. It only does this in the winter and more consistently when the starting car temperature is right around or a little below freezing. It doesn't matter how many times I try to 'kick' down the throttle, it just won't slow down. Then, at some point into the trip, it will slow down to regular idle by itself. If the starting temperature is really cold or warm (summertime) the fast idle will kick down properly. Does anyone know what might be the most likely solution to this?? The rest of the car is in great shape but the fast idle makes me want to take a sledge hammer to it

Thanks for any help...

Barry

 

The choke or choke linkage is “hanging up.” Also, check the thermatic spring in the choke housing.

It may well be time for a carb rebuild kit.

fs

 

On the front top left of the carb you will find the choke pull off diaphram, it will have 2 vacum hoses going to it . When the car is started and you pinch off those 2 vacum lines , the choke should pull off.
The vacum lines come from the temp vacum 'switches' in the intake manifold, so be sure your coolant is full and block burped thru the 12mm bleed screw at the T-stat housing.
While you are underhood it's a good idea to check the dist vacum advances and the hot air door diaphram in the breather housing.