Honda Prelude Forum - PreludeDriver.com

I bought my 92 honda prelude s off my friend because he didn't have the time to work on it and didn't know what was wrong, so i need help identifying a problem. When i start the car it will run rich and switch to lean and keep going back and forth and it causes the car to not run for to long, we think its an ecu problem but were not sure because we know it can be other problems also.

help would be greatly apreciated, thank you

Is the check engine light flashing?

If so, you can get the error code using the following instructions:

viewtopic.php?f=3&t=14

The check engine light isnt lit up, and that isnt the only problem i believe im also having problems with the throttle body, because when i have it idling it will rev up to 3000 rpms and drop back down and keep doing that over and over again.

A fluctuating idle is most often caused by the Fast Idle Valve malfunctioning. The fast idle valve is about 4 inches long, and mounted vertically on the back of the intake plenum, next to the throttle body. The top of it has a cap that is fastened with (two?) screws. If you remove the cap, there is a (typically white) plunger inside. The plunger has a slot in the top of it. You can use a large screwdriver to turn the plunger and screw it down onto a shaft it is connected to. Oftentimes, this is all that needs to be done to fix the idle.

Also, make sure that the coolant in the engine has been properly bled. Bubbles in the coolant can cause idle problems if they get stuck in the fast idle valve.

This issue is discussed here: viewtopic.php?f=3&t=12

The Idle Air Control (IAC) valve spoken of is the same valve.

thank you so much, ill work on it this morning and let you know if im still having problems

i notice a hole on the under side on the hose leading from the fuel injectors to the engine, its sucking in air and that might be what the fluctuating throttle is coming from

Daluz wrote:i notice a hole on the under side on the hose leading from the fuel injectors to the engine, its sucking in air and that might be what the fluctuating throttle is coming from

Better fix that first. That might be your problem.

yeah, thats what i am thinking, im going to change that out but im also thinking of doing an engine swap for the h22a vtec engine, which comes with all the parts i need to change out. and i read how it runs on my tranny