Hillbilly

it.

I was washing the car tonight at work, and decided to tidy up the engine bay a bit. Sprayed the engine down with some Simple Green, started the cold motor, and used low pressure water for a rinse. I've done this many times in the past, never had an issue.

And we have a misfire! It seems that when I sprayed water at bank 1, a few seconds later it would stumble, and catch right back up. This confirms that I have a leak somewhere.

I have suspected it for a while, but really didn't know. I have tried using water before, but only from a spray bottle...not a garden hose. Hopefully this accounts for my skewed fuel trims also.

I figure that if it can pull water into the cylinder and cause a miss, it damn sure can pull un-metered air into the cylinder causing the motor to actually run lean so the computer trys to compensate by dumping more fuel...causing a too rich condition and eventually throwing a too rich code. Does this sound logical?

I drove it home(about 2 miles, no highway), and it stumbled like crazy under high load/full boost conditions. For example, gently accelerating in 1st and 2nd gear was fine, but 30mph and full throttle in third caused it to misfire badly, setting off a flashing CEL. Now, I know this was due to the water, and the plugs were probably wet....so I'm not really worried about the actual misfire....just how the water got in there to make it miss.

Started it back up about 1/2 hour after I got home and hooked up the VAG-COM. The scan:

Sunday,28,September,2008,21:14:01:57405
VCDS Version: Release 805.1
Data version: 20080823



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Chassis Type: 8D - Audi A4 B5
Scan: 01 02 03 08 15 16 17 25 35 37 45 55 56 57 67 75 76 77

Mileage: 130630km/81169miles
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Address 01: Engine Labels: 078-907-551-AHA.lbl
Part No: 4D0 907 551 AH
Component: 2.8L V6/5V MOTR HS D01
Coding: 06201
Shop #: WSC 06335

5 Faults Found:
16795 - Secondary Air Injection System: Incorrect Flow Detected
P0411 - 35-00 - -
17930 - Camshaft Adjustment; Bank 2: Malfunction
P1522 - 35-00 - -
17927 - Camshaft Adjustment; Bank 1: Malfunction
P1519 - 35-00 - -
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16685 - Cylinder 1: Misfire Detected
P0301 - 35-10 - - - Intermittent
Readiness: 0000 0100

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Camshaft adjustment codes are because I have the VVT unplugged. Gets rid of a very noticeable flat spot in the PES tune. Not an issue.

Cleared the codes, plugged the VVT back in and took it for a spin. Ran a log of blocks 032, 002, and 014.

Fuel trims @ idle stayed at -3.5ish constant on both banks. Trims @ part shot up to -6.5 and -7.3.

It recorded 4 total misfires, but no code was thrown. I never felt them, no stumbling or hesitation. I assume the water burned off and the plugs dried out.

Any ideas where to start looking?

And I'm new to using a VAG-COM, so if there are other blocks I should log/check...I'd like to hear your input.

Sorry for the length of the post, especially with no warning.

cparke

If it was running lean and the ECU adding fuel to compensate, I thought the fuel trims would go positive to reflect that fact and you'd eventually get a "system too lean" fault.

I also have a car that seems to run too rich on bank 1 multiplicative/partial (-10% to -13%) and has negative trims accross the board. I haven't been able to find a intake/vacuum leak anywhere, however, never tried spraying the engine though because I don't want to get wiring and electronics wet. Occassionally, I'm also getting misfires on cyl-1/6 causing flashing CEL, and I don't think it is the coil because we've changed it twice now, must be a lean misfire. I changed MAF, ECT, EVAP purge valve, intake duct gasket, and jet suction pump among other things without any luck resolving the problem.

However, last night I made an amazing discovery---when camshaft adjustment is activated (which you need to use WOT to do), bank 1's adjustment is the wrong way (measuring block 90 shows -12deg and -21deg)! Bank 1's cyl-1,2,3 all shutdown (total misfires on the bank) while this backwards cam adjustment was active and a flashing CEL briefly ensued. Have to think all these things are related, just don't fully understand how these systems work so I'm helpless!

cparke

The only new suspicion your experience demonstrates to me is maybe a bad secondary air combination valve (and/or pump, which I think I may have as the pump seems to be blowing air up under the hood while it is running even though it also enough air enters the exhaust at the same time), when it isn't operating, is allowing some exhaust to enter the airbox. That would mean a failure of the secondary air combination valve, wouldn't it?

I've also found that if I drive the car with the MAF not breathing through the airbox, trim values are much more normal. Maybe these are clues that could help you too?