When I hit the throttle it keeps climbing after I let off the throttle. The throttle cable is not sticking. What could this be?

The car is a 1991 Honda Accord LX Coupe 5-Speed. When Im driving the car will sometimes accelerate by itself after I release the gas, but when I press the clutch the rpms rise, then drop back to idle.

 

Have you cleaned the IAC?

 

yes i have I also have cleaned tyhe FITV, and TB.

 

Have you done anything with the air boost valve?

This is the same one that "sticks" when throttle goes "too far closed"? So please check the linkage for full and free movement.

 

Yes the thottle used to stick closed, but I fixed that by adding a little cap on the stop screw, it does not cause the rpms to raise at all.

Today I checked the throttle cable and it does move freely I though maybe it didn't, but it did.

This issue has been going on for a while but now I want to fix it.

Right now I have the line from the air boost valve that goes to the intake capped because it used to cause a lumpy idle. Is it still doing something?

 

Very well could be. If the throttle "plate" is closing and the rpm's are going up, you are getting air into the engine from another source.

Time to spend some time uder the hood, work the throttle by hand until you can reproduce the issue, check to be sure the "plate"/cable are going closed. Then find the leak......

Why have you not cleaned or replaced the air boost? I hate by-passing OE set ups and then try to chase "other issues".

 

Curtie - you need to hook that back up and fix the root cause.

You are not going to be able to redesign the Honda setup so you need to just get it to work the way it was designed to.

Hook up the air boost and lets see if the throttle sticking goes away.

Then we can work on the lumpy idle.

 

Ok I hooked that line back up and would you know it no more sticky throttle. It also didn't have a lumpy idle YET. Last time it did the same thing. I think it would only do it when warm if I can recall.

 

If it come back, try cleaning the air boost.....

 

how would I clean it? I tried to remove the 2 screws before, but they wouldn't budge.