Dareng

Hey everyone,

I must be having an absolute tard moment here. This is my problem...

Whenever I'm driving, and come to a complete stop where the engine drops to idle speed, all of a sudden it starts to drop rpm, and then return to normal, sometimes low enough to almost stall out. I have replaced the IAC valve 3 times. Reason being the second time this idle thing happened, the CE light was on and gave a code of P0505, IAC valve failure.

But this is where the "of course" moment happens in my story...it doesn't do it all the time...regardless of weather, time of day or driving conditions.

I'm absolutely stumped...i don't understand it...what could be causing this problem.

P.S, engine was replaced with a rebuild with about 50K about 6 mos ago. All gaskets, seals, belts, plugs, wires...etc were replaced prior to install.

Thx,
Daren

jdm_416

i had the same issue i changed all spark plugs and bought used dizzy from a jdm store and it fixed my problem

D.T.P

If the cel is not on anymore, it may not be your issue. As mentioned above, a tune up is a good idea. Check your plugs, make sure they are gapped properly, because i've seen plugs out of a box that were way way way way off . Last time, bought 2 packs [2 in each] and not a single one was to spec, and they were pre-gapped.

rick10

I had a somewhat similar problem. As it turned out my alternator was about to go. Ever since i replaced the alternator amd change my battery my car idles perfectly

I had this problem for a few months until my alternator went one day . I also cleaned my tb and it did help.But it wasnt until i changed the alternator and baterry that my problem was gone

F8i

iTrader: (10)

There is an idle screw you could adjust by your IAC.
Spark Plugs always a good idea.
Possibly watch your voltage... Could be a shady alternator. Maybe there's something having too much draw. Try driving it hard'ish with all your Defrosters on, Fans blowing, Lights on, then come to an idle. See if that stalls it out.
-B

l.d.forget

another thing could be a vaccume leak.

Persia

Check all grounds, U would be surprised how important those little wires are.

Dareng

Thanks for all the info guys. But oddly enough, when it was at my mechanic, we were pulling it out of the bay and went to start it. It wouldn't start. Long story short...ignition coil. So we changed that and (knock on wood) it hasn't done its little fit again. Hopefully that fixed it. Thanks again for all of the info

rick10

my jetta had the same problem !!! I had to change the damn thing like every year .

D.T.P

Lol you mean the coil pack? I had a stack for my buddy back in the day. Vr6 especially, go through them easily.