MM120

I go to start my car in the mornings,& when it fires up the tachometer shoots to about 2000 rpm's, & plummets to about 200 rpm's. I give it a little gas to raise the rpm's to approx. 1,200 rpm's for about 5 seconds, & release the accelerator. It drops down to normal idle rpm's & maintains it. When I start to take off, the car hesitates & nearly dies. So, I give it gas just like before, but I have to get the RPM's to about 2,000 before it'll take off w/ out hesitating. I'll drive about 1/2 mile down the road & no problems after it starts going. This only happens after the car has sat overnight, & it does this everyday. I've cleaned the ICV & throttle body thoroughly, but it doesn't get rid of the problem. Any ideas?

axisaudia4

without the idle surging like yours. i have no idean what it is though.

AudiMick

My car did this too.When you clean the ICV you need to let the valve soak in throttle body cleaner (just the mechanical part). Lay it on its side and fill up the chamber and let it sit for 1/2 hour. If your vacuum tubes are old replace them. Also remove your throttle body and clean it and replace the gasket.There is a vacuum port on the TB that goes to the plenum that is normally blocked with carbon. If you have more than 70,000 miles remove and clean the EGR valve and passage.This is what I did (the parts are very cheap) and my idle is now rock solid with AC on or off.

MM120

I know what you mean about the vacuum ports; when I cleaned the TB, I had to use my trusty Snap-On pick set because I first tried to unclog all the ports (on the TB & intake manifold)with toothpicks, but they kept breaking. I didn't know about the EGR though. Is it just a bolt on part?

moribundman

is on the passenger side right under the "intake manifold switchover actuator" and next to the throttle body. Two color-coded (if original) vacuum hoses go from the plenum to the EGR valve. The EGR valve is attached to the intake manifold with 2 10mm bolts and screwed on top of an exhaust line. I did remove the EGR valve from the intake manifold, but I did not remove it from the exhaust line. You will need a 7/8" crows foot to get the EGR valve off the exhaust line. You will have to replace the EGR valve gasket. The part number is 026-131-547 for my '96 A4.

I believe you can check the function of the EGR with a vacuum pump. If you apply vacuum the valve must open. The EGR valve must also hold vacuum. If it doesn't, then the diaphrgam is leaking and the valve needs to be replaced (expensive).

You should scrape all carbon deposits out of the EGR valve. Don't use chemical solvents, because they will ruin the diaphragm.

AudiMick

<center><img src="http://pictureposter.audiworld.com/37725/egr_001.jpg"></center><p>The bad news is its easier with the throttle body off as you can't get to both ends of the EGR passage.You need a 22 mm crow foot wrench (or a 7/8 close enough)for the connection from the exhaust manifold and a 10 mm for the bolts that hold it to the intake. You need to remove the plenum, throttle body, that vacuum thingy (cruise control?) Move the coolant reservoir tank out of the way.Behind the EGR valve there is a heat shield that is held on by 1 13mm nut. You need to loosen it to allow the heatshield to move a little so you can get the crowfoot in there. Once you have the valve out test its operation .Use a piece of wire in an electric drill to clean out the EGR passage in the manifold. Then new gaskets and vacuum tubes and put it all back.Takes about an hour and a half. Allow for a significant amount of cursing.

MM120

car when i put it back on.

MM120

where i can get the little female ball-&amp;-socket adaptor (plastic) that screws onto the actuator arm? Mine broke &amp; the door stays closed at all times. :0(

moribundman

Should the actuator rod start moving when the engine speed exceeds 4500 RPM?

MM120

Mine moves at around 4,000 rpm's (when it works)