82 honda prelude engine surge while shifting


#1

Hi all,



Hoping someone can help me understand the problem I am having with my car.



I have a 1982 Honda Prelude, 5-speed. Of late, it has been having an intermittent problem which has been bothering me.



The car will warm up and idle at about 1000 rpm as expected. But when I have driven the car around a little, when I accelerate, something triggers within and the the RPM just shoots up to 2000 and stays there even if I put the car back in neutral. Thereafter, every time I press the clutch to change gears, the engine surges and the RPM goes up to 3000. When the gear is engaged it comes back down a little.



The strange thing is that this doesnt happen all the time. Sometimes the problem will go away and the car will run just fineā€¦and then suddenly it happens again. The problem is more pronounced after I have driven the car for a while. If I dont drive the car for a few days and then drive it the problem usually corrects itself.



I took the car to a mechanic and he said the car was too old and must have the carburetor going bad. But I am getting about 34mpg and no smell of fuel or no funny exhaust smoke etc to indicate that I have a fuel combustion problem.



I dont imagine it is a vacuum leak because the problem does correct itself and could remain corrected for a few hours before it happens again.



From all the information I have read, I have come up with the following possibilities:



- Carburetor



- Fuel Filter (this car has 2 fuel filters)



- Fuel pump



- EGR valve not opening and closing properly



- Tune-up (spark plugs, distributor). Engine may need degreasing



- vacuum leak



Can anyone help rationalize the problem.



Thanks very much for any responses!



Sunny


#2

Most likely, carb
Second most likely, carb
Third most likely, carb
Fourth most likely, vacuum leak associated with the carb

You probably have a sticky linkage. Does it do this when you rev it up in neutral on the highway or in the driveway? Take off the air cleaner and move the throttle around with the engine running. Does it rev up and slow down the way it should? You may need to find and old-fashioned carb expert.


#3

BeadsandBeads,
Thanks for your response. I havent tried reving it in neutral. I can give it a try. This is usually triggered when I start the car from a dead stop (say at a traffic light). When I shift to third gear the engine will suddenly rev for no apparent reason. Thereafter, every time I depress the clutch the engine seems to surge.

If it has to do with the linkage, would I need a new carb or can it be fixed without a carb overhaul. Thanks again!