Questions and Answers
The Honda Prelude Si From Hell
Q. Hi there! I have a 1988 Honda Prelude Si from hell. Among its many problems, when it is stopped and idling at a stoplight or anywhere, it surges between 1000 and 2000 rpms. It is very annoying and the mechanic doesn't know what's wrong with it.
He says that the fuel injector is fine and says it may be a problem with something that sits way under the engine and needs to be cleaned, but he would pretty much have to take the car apart to get to it and he isn't even sure that will fix it. Do you have any suggestions for me? I would rather not pay for hours of labor only to find that it doesn't fix the problem. It is a 1988 Honda Prelude SI, 4 cylinder engine, manual, 176,000 kilometers, fuel injected, no ABS brakes, no A/C, power steering. Thank you!!
Sincerely,
MaryA. With that amount of milage on it, I would suspect the throttle chamber is pretty well gummed up. I would have your mechanic take it apart and give it a good cleaning. There are a couple of idle air bypass channels that can get restricted or closed up over time by gum build up.
If it still fluctuates after that, then I would suggest he look at the Idle Speed Control Valve. There are some basic tests in the shop manual he can do to confirm that is the problem.
