I posted a while back regarding a long start (6-8 seconds) when the engine is warm on my 2001 A6. The RPM's will also jump from 200 to 400, then to 600, then to 800, before idling. Cold start everything is fine. I addressed many of the potential solutions that not only were recommended but the codes backed up. I have changed the vaccum hoses, plugs, fuel pressure regulator, battery, coolant temp sensor, fuel pump & filter, water pump and the coil pack in the last nine months.

I gave up after I was not pulling any codes from my vag-com. I did not want to chase something that was not there. A month had passed and I plugged it in today and found many codes:

16534 - Oxygen (Lambda) Sensor B2S1: Malfunction in Circuit
P0150 - 35-10 - - - Intermittent

16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent

16690 - Cylinder 6 Misfire Detected
P0306 - 35-10 - - - Intermittent

16686 - Cylinder 2 Misfire Detected
P0302 - 35-10 - - - Intermittent

16825 - EVAP Emission Control Sys: Incorrect Flow
P0441 - 35-00 - -

I want to say that there had been a suggestion that the EVAP Purge Valve was functioning incorrectly and that it was not purging prior to the engine starting which would in turn cause the long start due to saturation. Would this confirm that idea? There is also a small leak of some fluid from the upper left area under the hood (when looking from front to back) is this related?

http://wiki.ross-tech.com/wiki/index...5/P0441/001089

I came across this link. How would I go about performing these output tests to determine whether the N80 or the N115 valve needed to be replaced? Any other suggestions on how to approach this and finally fix this starting problem?

Thanks!

 

The EVAP system has absolutely nothing to do with engine performance. Look at the back of your engine and see if you still have the black top coolant temp sensor installed. If so, replace it with a green top sensor.

 

The one that I replaced was located at the back of the engine. It was relatively hard to access but it was located more toward the lefthand side, midway down the back of the engine if that is the one you are referring to (which I think you are). It is a new green one which was replaced in February after I was pulling codes for it.

EDIT: I should also add that this did reduce my starting time significantly. It was at one point 12-15 seconds but after this part was replaced it dropped to 6-8 seconds when warm.

 

Well that fudges up things. Still something is causing the misfire codes. Lets start with the basics, im gonna assume this is a 2.8L engine because you haven't said so yet.
Pull the intake line at the throttle body off and spray brake cleaner in there and wipe out the carbon with a shop rag, moving the valve open and closed while cleaning it.
Buy a can of seafoam, locate a manifold vacuum line and suck the seafoam into it until the can is empty, this will make the engine bogg down while doing this. This will also make a LOT of toxic smoke out the exhaust so do this in a well ventilated area.
If its REALLY dirty there will be a lot of smoke, and it will most likely foul up the spark plugs, so you may need to replace those again after the treatment. Get back to us after thats done. If this is a 2.8L im confident this will greatly improve (if not fix) your problem.

 

It is a 2.8L Quattro. I will give those a try and get back to you. Thanks.