Synthbent715

Hey guys, been having this problem for a while now. When im sitting at idle, in gear, with the AC on (and sometimes even with it off) the RPM's will jump between 800 and 450 rpm's and my car will shake and feel like its about to die. I just got it back from the dealer for this problem, and a CEL. They replaced my Idle Air Control Valve, and installed a new Charcoal Canister (to clear the CEL) Well, no more CEL as of yet, but the idle problem has not been fixed. I have even tried to turn the idle screw up, and it then idles higher, but when it does drop...it still drops to about 450.

I have read alot about Idle Control Solenoids and things like this, or solenoids on the AC that tell the Ecu when the clutch is engaged so it can tell the IACV to idle up. Is there anything like this on our car?

This is driving me crazy, and I had a pretty crappy time at the dealer, it took about 3 weeks before they even took any time to help me, then they just guessed what the problem might be.

Any help guys?

MrBurrito

iTrader: (2)

well if it happens often then u should take it back to the dealer. if they don't want to fix it you should file a complaint and maybe go through corporate.

msriotdoll1

i had/have the same issue as well. It still happens every once in a while. I also had the idle control sensor/valve . I also had the MAF sensor cleaned out.I came in and complained so much about the sporadic idle that they had a regional senior tech come out. He hooked it up to his laptop for 30 minutes and said that it was all within specs. He was very impressed with the numbers actually. Mine will do the hard idle sometimes when i've been driving in lots of stop and go traffic or if i haven't turned on the car in a few days the car does all kinds of strange stuff. Feels like the engine is about to bog down and shut itself off.
I have no idea what else to do. I just live with it. my car btw has 29K odo

enerlevel

i also have the same problem with my 04 ist.
on ac the rpm keeps jumping..... i still havnt fixed the problem but hope to fix it soon. do try one thing , turn ur steering all the way and see if ur rpm adjusts itsself or not.
also check ur trottle for dirt deposits... , check ur plug wires....

i have also heard a clogged or dirty catalytic converter can also cause ideal problems....

STEELBREEZE

When we installed a hand made ground wire kit under the hood, it leveled out the idle as well a a few other bonuses. The idle dropped slightly and steadied right up. Easy enough to give a try anyway.

Synthbent715

Hey guys, I figured it out.

After 3 trips to the dealer, my warranty company paid $800 for them to put a charcoal canister, iacv, and fuel sending unit on my car...only for all three codes to trip the next day, and the idle problem still remained.

I started looking around under my hood and noticed that the Vacuum Switching Valve, located on the side of the air box, had electrical tape all over the wires. I unraveled the electrical tape and saw this:


It looks like when they (whoever did it, NOT ME) were crimping the black wire, they pinched the red wire and broke it on the inside. I cut it, soldered it back, and plugged it up. Reset the light, I am 300 miles into this tank now and the idle has been PERFECT. It has not faltered once, and my CEL has not come back on again. Crazy to believe that such a small thing caused so many problems but I believe that it did.