Check for vacuum leak?  Pull off the Crank Case Breather Hose and place your finger over the hole while revving the engine, if you finger is held at all there is a vacuum leak in the lower intake.  If not then idle engine and use propane torch (not lighted!!) to bath any areas that might be a vacuum leak such as around the gaskets, TB etc, engine speed will change when raw propane finds a vacuum leak.  I don?t care if people got new alternators and batteries :) , it?s a simple test, leave nothing to chance or continue to be bothered by this problem and maybe be embarrassed when you do find an odd problem in the charging/starting system later :oops: .

Last would be to play with an chip emulator with the engine running, there are a few timing tables but maybe a lot would be answered if a scan shows odd values with the IAC Counts!? (talking and thinking here).  Maybe the INT is resetting since it cannot get a good hold on the fuel trim, there are a lot of things to check in a scan.  Back to the chip, there are a large number of idling tables with such things as IAC control and setup, others too that effect how the engine?s idling is considered when in P/N etc, far too many to list here, and spend a week describing each or a combination of some that could play a part  :? .  It may be that the issue was not enough before the swap to be a bother and now with the swap, the problem is more noticeable.

(oops, edited/corrected)

Jeff M

For the problem from my point of view...

PCV on my car has been moved from the stock location *under the plenum* which was plugged, and moved to the side of the plenum, and the propane trick has been tried to no avail, we are going to intercooler pressure tester and see if we can find any that way, the engine is much to loud to be able to find any small leaks.

maybe doing the chip thing will be the only way of fixing the problem, we'll try a few things you have suggested first of course, then get into the more drastic stuff if need be..

Well being up for too many hours and see what that gets me :roll:  I corrected my description in that last post :oops: .

Jeff M

I know it doesn't have a vacuum leak.  The very first time I started up the engine after figuring out my oil leak problem, it definatley had a vacuum leak, but I fixed that.  The plenum gaskets and the EGR block-off plate that I made were both leaking.  Put new plenum gaskets in (again), and resealed my block off plate with RTV and the vacuum leak went away.  With 20in.hg. at idle I'm douibting there can be a vacuum leak somewhere.  Not only that, but the engine idles smooth and doesn't hesitate or miss at all.  It could possibly be in the chip, and thats why I wasn't worried about the problem, because I figured that I would correct it when I edited the chip, but since others are having what sounds to be the same problem, I'm thinking maybe it isn't in the chip.  

But anyways, definately no vacuum leak.

Shawn

Ok, so you don't have a vacuum leak 8)  Still be good for others to ensure this with theirs, leave nothing to chance or be pissed later  :lol:

Jeff M

One thing Luke left out... at times the little beast does a fun trick where, from rest, it will accelerate to around 20-25mph without me giving it any gas.  Sometimes it will continue the entire time the car is running, and other times it starts behaving when I come to a complete stop.  There seems to be no pattern - I'll start it once and it's fine... start it again a couple hours later, and it's acting up.

Quote from: kittieOne thing Luke left out... at times the little beast does a fun trick where, from rest, it will accelerate to around 20-25mph without me giving it any gas.

Did you buy a TGP or an old AUDI?? :shock: Some of the "old farts" on the board may remember those! The days of the "accelerated by itself" Audi cars back in the 80's? :lol:

Sounds to me like you may want to check the throttle body return spring and also hook it to a diag tool to also see what the IAC counts are. That issue would drive me crazy for sure! 8)

The TB spring is good..
I finally got a chance to hook the car up to the laptop, and I ran a scan on a cold engine, and recorded until it fully warmed up. Of course, this time it idled just fine. All the IAC counts, and read outs looked alright, nothing was unusual. I'll post the file up here when I get a chance to copy it off of the laptop.

Well like Jeff said look for vacuum leaks. It is possible that when it is really cold that a leak is opening up from metal or a plastic piece shrinking so much from the cold letting air in.

It is a tricky one...but hell Luke you found the wire shorts on your TGP when no-one else had a clue what to look for. Be one with the car...talk to her...feel the car!! :wink:

My car has recently developed this problem, sometimes revving up to 3k or more!  Once I drive it it still happens every time I depress the clutch.  I did replace my Alternator, and it is a 105 amp, but I don't think the engine would rev that high...?!

cant u use carb cleaner instead of propane to find vaccume leakes, my car idles just the same, its wierd

brake cleaner works too.

I'll also run a aldl scan on my TGP..it just did it today...could be that it hadn't been on for weeks. 2500 rpm from the get go.