# One for the Big Boys, 1-2-3 Bank Misfire @ idle only



## vagbahn (Dec 13, 2009)

99 Audi 2.8 quattro , auto trans , stock engine and software. 
DTC, Misfires cyl 1,2 and 3 only at idle or below 800 RPM
Raise idle above 800 and all 6 purr like a kitten, fall below and 1,2 and 3 completely cut out. 
First thing I thought was possibly clogged cat (debunked)
Then I thought perhaps the coil pack was staging wrong (debunked)
Then my buddy at the dealer came up with a running compression test, perhaps the compression was dropping due to chain tensioner phasing of the intake (debunked)
Thought the ecm might be dropping the pulse for the 123 injectors (debunked) VIA pulse tester 
Spark plugs (debunked)
ECM (debunked)
Posessed by the Devil... hmmm... perhaps 
Anyone who can come up with somethig on this, and you will have outwitted the best tech at Champion Audi and myself , an Audi tech for 25 years..


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## O_o (Nov 12, 2009)

Timing belt slipped?


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## O_o (Nov 12, 2009)

I suppose that would have turned up on the compression test though... I'll change my guess to a passenger side intake manifold leak.


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## O_o (Nov 12, 2009)

Meh. Forgot it has runners. Strike two, I guess.


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## vagbahn (Dec 13, 2009)

*Next We Dig Deeper*

No one can put their finger on this yet, and it's now had the word of the regional Audi rep " That' F**k'd up" ... 

My latest theory is to check the intake cam on bank 1. Perhaps some brainy individual changed the cam tensioner gasket and couldn't count to 16. I would think that this would show on a cold and running compression test.. but still all cylinders are within 5 lbs of each other...


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## cnctech (Dec 6, 2012)

*Cam chain tensioner*

Hi. I had an issue with my tensioner and finally figured out that if the chain jumped a tooth, the cam angle with the VAG COM will show exactly 22 degrees off. Also when the tensioner to advance intake timing, you will see the total advance is 22 degrees.
Hope this helps.


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