SuperFishstick

Well first off, No CEL. Haven't had time to check for ghost codes. Will do today after work. Also. my fuel economy sucks. But what i just noticed is that if i shift to neutral the rpms fall down, sometimes they go below 500k and then like half a second later they jump back up to like 650k or what ever is the proper idle engine speed. What do u guys think it is. Also.. my idle is not as smooth. When the car is running, with the hood open, the hood vibrates and shakes. Againm i don't think thats normal!

Scruit

Try cleaning your TB first. Buildup will cause bad idle.

sweetdaddy

Clean the TB inlet and butterfly like scruit says, as well as the IACV. IACV is more likely the culprit, as it's job is to meter idle air when the butterfly is closed.

SuperFishstick

thanks guys. I cleaned the TB, but not the IACV. CAN U tell me where it is?

sweetdaddy

It's on the firewall side of the TB. Theres a short set of instructions for removing and cleaning it in 4th Gen FAQ's. There are 3 components on a metering block. Two FICV valves for AC idle and an IACV motor. Clean 'everything up with carb or throttle body cleaner. As much, or more crud, is in these components compared to the throttle body inlet and butterfly.

sweetdaddy

Might wanna replace or at least inspect & clean your PCV valve too.

SuperFishstick

Thanks man. I'll get right on it.

ben99sel

iTrader: (10)

If his IACV was bad, would it give a cel or a ghost code?

MaximusMax

It's definately your IACV. I had the same exact problem. I replaced that, along with my knock sensor and HOLY SHYTE!! The car pulls harder than the day I bought the dam thing. Replace those, your fuel economy will go up AND you will feel a helluva lot more power.

njmaxseltd

iTrader: (19)

What spark plugs are you running and how long since they have been changed?

SXN

i agree... try cleaning your tb click here if u dont know how

sweetdaddy

Only if the IACV or solenoids on the metering block was malfunctioning electronically. No way for the computer to know of crud build up on these.

Jatan

iTrader: (3)

SXN he cleaned his TB already

It's not that hard. It has 3 connector things connected to it. They are purple, pink, and gray connectors. I think it also has an intake hose connected to it or something. If you can't find it, I can email you a picture of it

Mine was dirty! When I was cleaning it, people walking by looked at me funny... I'm like the only one on the block that works on a car... I get a wierd feeling when I open my hood to do something

SXN

yea *cough* i read the whole forum... anyway. A question though, is it possible dirty connectors in general can cause this? i know the knock sensor wires need a good scraping every once and a while, and the battery terminals should be shiney... any application to this problem?

zealotnyc

how much does a replacement IACV cost?