Misfired When Cold Engine, Help, Running Out Of Ideal
08-11-2010, 08:19 PM
#11
AudiWorld Super User
Thread Starter
Just start the engine and remove oil cap, engine still run normal, no misfire or stall, so I guess the PVC valve is OK.
Last edited by BSCA4; 08-11-2010 at 10:08 PM.
08-12-2010, 05:53 AM
#12
AudiWorld Super User
Just for info: beginning sometime in 03 (not sure when), the "pancake" or PCV valve is mounted near the the combi valve which is between the valve cover and the firewall. If you have an early 03 and 02, it is mounted near the turbo. Combi valve is silver, "pancake" or PCV is black.
Just a thought, if the spring inside the pancake is "sticky", maybe it causes that one misfire before it moves. Maybe try removing the pancake and spraying some carb clean in there to loosen up the gunk.
Just a thought, if the spring inside the pancake is "sticky", maybe it causes that one misfire before it moves. Maybe try removing the pancake and spraying some carb clean in there to loosen up the gunk.
08-12-2010, 06:19 AM
#13
AudiWorld Super User
Thread Starter
Clean PVC valve, still misfire. The first 10 - 15 sec is hell
Last edited by BSCA4; 08-12-2010 at 08:01 AM.
08-12-2010, 09:55 AM
#15
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since you showed a brake vacuum code did you verify all vacuum connections to the brake booster and verify booster is intact and working properly? It is possible that you have a vacuum leak at the brake booster internally. This is more difficult to find and almost always overlooked. If you can connect a vacuum guage to the brake booster line and look for a slow leak.
08-12-2010, 11:42 AM
#16
AudiWorld Super User
Thread Starter
since you showed a brake vacuum code did you verify all vacuum connections to the brake booster and verify booster is intact and working properly? It is possible that you have a vacuum leak at the brake booster internally. This is more difficult to find and almost always overlooked. If you can connect a vacuum guage to the brake booster line and look for a slow leak.
Would a vacuum leak will cause it misfire all the time? My case is just 10 to 15 sec when engine cold.
08-12-2010, 01:13 PM
#17
AudiWorld Super User
Seems as though if there is a small leak, that it might take 10 or 15 seconds before the vacuum could build to the point where no misfire would happen and then enough vacuum is maintained after that. I can see this. This may be a good call.
08-12-2010, 01:15 PM
#18
AudiWorld Super User
Thread Starter
OK, let me try to debug to see any vacuum leak from the brake system