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Audi A8 1997-2003, S8 2001-2003 (D2) Engine misfiring


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Last Post: Sep 24, 2009 11:01 PM Last Post By: Little Mark
Little Mark

Posts: 2
Registered: 09/14/09
Engine misfiring
Posted: Sep 14, 2009 3:32 PM
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Here is what I got from my initial scan.

VCDS Version: Release 908.0
Data version: 20090830

Thursday,03,September,2009,16:24:23:25180

Chassis Type: 4D - Audi A8 D2
Scan: 01 03 08 11 15 16 17 18 25 35 37 45 55 56 57 65 67 75 76 77
02

Mileage: 189280km/117613miles
-------------------------------------------------------------------------------
Address 01: Engine Labels: Redir Fail!
Part No: 4D0 907 557 D
Component: 4.2L V8/4V MOTR AT D05
Coding: 01273
Shop #: WSC 00000

9 Faults Found:
18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 35-10 - - - Intermittent
18020 - Engine Control Module Incorrectly Coded
P1612 - 35-10 - - - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16685 - Cylinder 1: Misfire Detected
P0301 - 35-10 - - - Intermittent
16688 - Cylinder 4: Misfire Detected
P0304 - 35-10 - - - Intermittent
16687 - Cylinder 3: Misfire Detected
P0303 - 35-10 - - - Intermittent
16686 - Cylinder 2: Misfire Detected
P0302 - 35-10 - - - Intermittent
16692 - Cylinder 8: Misfire Detected
P0308 - 35-10 - - - Intermittent
16486 - Mass Air Flow Sensor (G70): Signal too Low
P0102 - 35-10 - - - Intermittent
Readiness: N/A

2 Faults Found:
17087 - Brake Switch (F): Electrical Malfunction
P0703 - 35-00 - -
18265 - Load Signal: Error Message from ECU
P1857 - 35-10 - - - Intermittent


I used my manual and it said that my air flow meter was suppose to read something like this at idle 3.3-6.5 or something like this. Mine was currently reading a around 14.7.
I checked my connections and found them to read what it suppose to be, so being an idiot I purchased a new air flow meter and it didn't fix anything except now the reading for my air flow meter is around 4.

I erased the codes and this is what came back up.

Monday,14,September,2009,14:49:06:25180
VCDS Version: Release 908.0

Address 01: Engine Labels: Redir Fail!
Control Module Part Number: 4D0 907 557 D
Component and/or Version: 4.2L V8/4V MOTR AT D05
Software Coding: 01273
Work Shop Code: WSC 00000
4 Faults Found:

16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16685 - Cylinder 1: Misfire Detected
P0301 - 35-00 - -
16688 - Cylinder 4: Misfire Detected
P0304 - 35-00 - -
16687 - Cylinder 3: Misfire Detected
P0303 - 35-00 - -

Readiness: N/A

Would it be just the coil packs or ECM issues?

This is how it started, I was driving down the interstate and it just shut off. I thought the trans went but the engine lost all power. It is running on a few cylinder, but will not pull itself and will not rev over 2300 rpms. On the scanner it say's percent load and it read very high when at idle. i don't know what this means either.

Thanks for your help.

Mark Arnurius

Bresha

Posts: 415
Registered: 02/23/09
Re: Engine misfiring
Posted: Sep 16, 2009 1:59 AM   in response to: Little Mark in response to: Little Mark
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Mark,
the reading of MAF sensor was abnormal, it should read approx up to 6.0 gr per sec and replacement of the MAF sensor fixed this issue as you stated "it's read now around four gr/sec" Since you have a scan tool try to test cam adjusters and check at idle misfire count at affected cylinders. one cylinder miss might affect other cylinders, and i would go for the basic, regular maintenance, spark plugs, wires, fuel filter, check the fuel pressure etc....

Bresha
Little Mark

Posts: 2
Registered: 09/14/09
Re: Engine misfiring
Posted: Sep 24, 2009 11:01 PM   in response to: Bresha in response to: Bresha
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Thanks for your response.

I changed the plugs and switched my coil packs to learn that the miss didn't move from 1-4 cylinders. Once I did this I got an injector pulse width LED and found out that 1-4 injects were not getting pulsed and 5-8 were. I checked my wiring to the ECU and it was good. Checked the manual and found out that the computer is bad. I found a place in Jacksonville, FL to rebuild it with a lifetime warranty for $530. Audi wanted $2400 for a rebuilt one and I couldn't trust getting a used one because of how the car just died on me. You always trust that your car will run and now in the back of my mine I will always be more careful when I pull out in front of people. The scanner did find that the air flow meter was out of spec and I also found that my LF speed sensor was bad, so buying the scanner was a good deal after all and alot cheaper than going to the shop.

Later,

Mark

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