97Z-M6

car idels high when i decellerate, like if i coast to a stop the car will idle down about 3 or 4 seconds after i stop, and it idles at about 1500 rpms. and it drives me nuts how can i fix it.

94Zpower

I was wondering the same thing because my A4 does it to

fbird95

Every F-body i've ever driven has done that, It makes sense for rolling stops especailly for the manuals. However it cant be helping the clutch or clutches in manual or auto cars longevity, especially during rolling starts.

OBE1 95Z28

Lubricate your TB blades (where the rod enters the TB). I had this problem after I cleaned my TB...lubed it and it went away.

Rodrigues

It sounds like you loaded an automatic pcm tune in your car... This is probably a longshot.

scoobysnax83

eeeeekkkk , there are like 6 million posts on this board about the same issue. Its completely normal. It keeps your vacuum pressure up for brakes as you stop. The same feature also keeps your rpm's up between shifts.

By the way, I love the few new icon faces we got.....Good Job!!!

Silver

It's normal to a certain extent. The IAC does get carbon buildup and the motor does get weak and several things can cause the idle to be higher than it should be. I have cut my idle follower about in half with editing and it's sooo sweet now.

Anyway, first thing to do is reset the IAC. Hold down the gas a bit while you crank the car. Let off the gas and let it idle for a minute or so. Shut car off, wait a minute or so then see how it runs.

If it's still high, take it off and clean it out with TB cleaner, not carb cleaner. You'll see the carbon buildup if your car's past 20k miles or so.

madwolf

No, he doesn't. Trust me on that.

I remember my car doing the same thing when I went to a 52mm TB but the problem was with the TB. (the blades were sticking)

smokindastangs

My car does the exact opposite; it idles low if I push in the clutch and hold it to a stop.

madwolf

That's the effect of the cam. Adding some timing at lower rpm/closed throttle will fix it.