Ok, car starts up and idles fine through datamaster at 800 rpm. But if I go into say second, and let off the clutch at 3000 rpm, the idle will stay at 3000 rpm for a couple seconds and slowly fall to 1100 if the car is still moving, as soon as I come to a complete stop it idles back at 800, but only at a complete stop. Im thinking maybe the IAC is gunked because the hose that comes off the valve cover into my throttle body has a lot of oil build up but any other items to look at? Checked all vacuum lines and they are good.

Also, how the hell can I stop that line from the valve cover from spilling oil into my throttle body? Can't I just buy one of those valve cover cone filters and plug the hole in the throttle body? Thanks.

 

I'm having the same problem...so far

-it's not the TPS

I'm getting a computer tune this coming week....maybe that will take car of something.

Also, I am using a non-delco O2 sensor in one of my headers...maybe that has something to do with it...what sensors are you running??

 

I have one delco and one bosch because they ran out of delcos. My TPS is perfect, checked it through datamaster, its at .57 at idle and when I let my foot off the gas. Im thinking my IAC is gunked.

 

yes, IAC is next on my list...i've heard that the IAT sensor can also cause some issues, and it's only $8...might be worth a shot...let me know how cleaning you IAC goes

I'm trying to remember when the probelm started for me, but I think it was about the time i changed out my O2 sensor...who knows...

good luck

 

IAT is brand new, its also functioning properly, helps to have a laptop. But my IAC also seems to be running fine, it just may be a little slow. I suppose i'll try it.

Anyone have a trick to stop that fricken oil gunk from getting into the throttle body from the valve covers?

 

No if its idling fine when stopped then its the tune, you have to alter the IAC follow vs. MPH table, it dictates how open the IAC has to be at a certain MPH and closed throttle, then when you come to a stop (full stop) the computer now looks to make sure the idle is at the preset level while cruising its just got a set parameter of where the IAC position should be, you want to decrease it you just decrease the stop table I belive its set pretty high at 20 on an M6, set it to 15 or so and you'll have harder decel and lower idle.

 

I got a madz28 tune, i've been trying to get a hold of ION for the last 3 days and no reply, longest its ever taken him. Is yours tuned Dave?

 

I ordered it like 2 days ago, asked him to lower my idle to about 700rpms....as soon as i get it and put it in i will let you know what happens

 

Now that I think about it, this makes sense. I had my VSS unplugged for the longest and it started doing this when it was plugged back in. Is there any negatives to actually lowering this as far as performance? I'd like to save as much gas as possible, I usually put the car in neutral with my hand on the stick when slowing down.

 

blow-by COULD be causing the oil to get into the throttle body, i would also check your pcv valve.

 

I do smell some oil burning when I really get on it, how can I stop the valve cover hose from getting into the throttle body?

 

Deutsch BF412 Valve Cover Oil Separator, avaliable in your local parts store for about $4. It's a plastic piece that fits into the stock valve cover and connects to your hose.