tom50

Ok so i read all the posts about hanging idle and went through all the steps. Cleaned EGR,TB,MAF, IAC, new TPS. I still have a hanging idle around 1300 and then will drop to 900rpm. I disconnected the tps and the car runs great. No hanging idle probs or anything but a check engine light. Am I hurting anything by disconnecting the tps or do you guys have any ideas? I am sooo sick of messing with this idle!!! Please help.

dman302

sounds like a vac leak to me. Check TPS setting for correct voltage, check for vac leaks...then check for vac leaks and finally see if you can find any vac leaks.

tom50

Lol so you think it could be a vac leak huh......how do i check that.. If I had a vac leak wouldnt my car run ****ty even with the tps plugged in?

dman302

no vac leaks can cause different issues..as can a bad tps sensor or setting....you basically need to follow each vac line from start to finish...when I have done it in the past I always liked to dab checked lines with liquid paper to keep the process easier.

tom50

Isnt there a way with carb cleaner?? or something

90GTRagtop

You can use carb cleaner or startign fluid (Ether) and spray it a little at a time near various vacuum components (don't forget the intake gasket areas) while the engine is running. If the engine speeds up, there's a leak near where you sprayed. Take your time to make sure each spray has had time to be picked up by a leak nearby. Do use an abundance of caution. Remember, these sprays are flammable. You don't want to light a flame thrower under the hood. Oh, and did Dman mention you should check for vacuum leaks?

Also, cleaning the IAC may or may not work. I have had them to clean and work, and I have had to replace them because they would stick and not clean up. However, mine have always stuck so the idle would be too low and shut the engine off at idle.

Good luck with it.

tom50

Well I tryed my buddys IAC also and did the same thing. His car runs perfect. Does the EGR valve have anything to do with idle or is it just for emissions? Should I spray the whole hose or ends or what. Im just trying to figure this out so im not spinnin my wheels. Do I need to soak the hoses or quick spray? Thanks for the replys.

tom50

Hello

90GTRagtop

Just spray lightly (see previous note regarding flammability). The spray will get caught up in the air being sucked into a vacuum leak and act like extra fuel. That will change the idle speed when you get near the leak. After it does it once, try again to confirm the area. This will help you to narrow down your search.

musclemustang94

hey a WAY better way to find a vaccum leak is to use propane. You can spend like 5 bucks for a special valve with a long thin rubber hose to put on the bottle and you just move it around near your vaccum lines till the idle picks up, thats where its leakin vaccum. Propane is a fuel so it will make your idle pick up.