97 A8 #4 cyl misfire

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97 A8 #4 cyl misfire

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97 A8 #4 cyl misfire - 9/12/2006 11:09:21 AM

MnJohn

Posts: 1
Joined: 9/12/2006
Status: offline

Having a serious problem diagnosing a misfire. Get a code of "cyl 4 misfire: P304". the engine is misfiring only in one cyl, #4

I've checked the compression, coil pack and changed it, check'd elec current flow and wiring, plugs, ignition, etc. I've cleared the code and restarted it and the code returns when restarted. I've swapped injectors to other cyl & code re-appears.

any ideas?? I've been working on audi's and vw for 25 yrs and this one has me stumped.

thanks

Post #: 1

RE: 97 A8 #4 cyl misfire - 8/19/2007 9:16:18 AM

rx7world

Posts: 5
Joined: 8/9/2007
Status: offline

I have a similar problem,

P0308 Cylinder 8 Misfire Detected
P0302 Cylinder 2 Misfire Detected
P0300B Random- Multiple Misfire Detected

I have swapped Spark plugs, coils, and injectors and the codes returned anybody?

(in reply to MnJohn)

Post #: 2

RE: 97 A8 #4 cyl misfire - 8/19/2007 8:51:44 PM

auditech79

Posts: 5081
Joined: 2/24/2007
From: Sacramento, CA
Status: offline

What year A8? Pre 04 A8's sometimes have problems with building up carbon the intake valves that can sometimes cause a miss-fire fault. A re-flash of the ecm would fix the problem but since there isn't one currently available that i know of try the old school fix and spray chemtool carb clean down the intake trick.

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00 A4 1.8T

(in reply to rx7world)

Post #: 3

RE: 97 A8 #4 cyl misfire - 11/8/2007 12:44:31 AM

dj_lex

Posts: 8
Joined: 11/5/2007
Status: offline

have the same problem on '96 a8 3.7 v6. Also cyl 4. coils and plusg and wires ok. Any solution? Perhaps bad ICM? You suggest valve is stuck open or close? i mean due to carbon build up?

(in reply to auditech79)

Post #: 4

RE: 97 A8 #4 cyl misfire - 11/10/2007 9:21:58 AM

dankhound

Posts: 2634
Joined: 10/17/2005
Status: offline

quote:

I've checked the compression, coil pack and changed it, check'd elec current flow and wiring, plugs, ignition, etc. I've cleared the code and restarted it and the code returns when restarted. I've swapped injectors to other cyl & code re-appears.

What were the results of all these tests? Does the injector get power from the ecm? You may also want to try disconnecting coils on different cylinders to make sure number 4 is the one that is actually misfiring.

(in reply to dj_lex)

Post #: 5

RE: 97 A8 #4 cyl misfire - 11/18/2007 11:16:58 PM

K4Ranger

Posts: 3
Joined: 11/18/2007
Status: offline

I have similar problems with my -97 A8. Cylinders 1 & 5 reports misfiring. Changed plugs, took it to Audi quick service, but they just told me that they have to do more extensive investigation (and more money). Going to change coils next. Hope it will fix it.... :-(

(in reply to dankhound)

Post #: 6

RE: 97 A8 #4 cyl misfire - 2/2/2008 10:49:58 AM

turkey

Posts: 2
Joined: 2/2/2008
Status: offline

my a8 3.7 has same problem on number 4 cylinder.changed coil pack,injector,compresions r all good.same as all other on this thread,has anyone found sollution yet??

(in reply to K4Ranger)

Post #: 7

RE: 97 A8 #4 cyl misfire - 2/2/2008 6:19:31 PM

dankhound

Posts: 2634
Joined: 10/17/2005
Status: offline

Try swapping the ignition control modules and see if the misfire changes to a different cylinder.

(in reply to turkey)

Post #: 8

RE: 97 A8 #4 cyl misfire - 2/3/2008 7:16:51 AM

Ska

Posts: 12
Joined: 11/25/2007
Status: offline

o2 sensor?

(in reply to dankhound)

Post #: 9

RE: 97 A8 #4 cyl misfire - 2/15/2008 4:12:52 AM

dj_lex

Posts: 8
Joined: 11/5/2007
Status: offline

Changing the ICM solved my problem. However, i have a huge fuel cons 19-20l/100

(in reply to Ska)

Post #: 10

RE: 97 A8 #4 cyl misfire - 2/22/2008 11:58:25 AM

turkey

Posts: 2
Joined: 2/2/2008
Status: offline

sorted. was a faulty icm. mine v high fuel con too. 20 mpg @ 80mph. at least they quick cars else i wud b moanin! lol

(in reply to dj_lex)

Post #: 11

RE: 97 A8 #4 cyl misfire - 2/24/2008 3:17:12 PM

koop

Posts: 43
Joined: 2/24/2008
Status: offline

Which ICM did you guys use to replace the faulty one with?

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97 Audi A8

(in reply to turkey)

Post #: 12

RE: 97 A8 #4 cyl misfire - 2/24/2008 10:32:06 PM

auditech79

Posts: 5081
Joined: 2/24/2007
From: Sacramento, CA
Status: offline

quote:

ORIGINAL: koop

Which ICM did you guys use to replace the faulty one with?

I believe you can pick them up at www.ecstuning.com, www.purems.com might have them also. The dealer way overcharges for that part.

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00 A4 1.8T

(in reply to koop)

Post #: 13

RE: 97 A8 #4 cyl misfire - 3/27/2008 3:56:18 PM

nhltfour

Posts: 136
Joined: 6/7/2006
Status: offline

exactly where is the ICM located in a 96 B5 qm?

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1996 A4 2.8 12v::K&N intake::Magnaflow exhaust::Ecodes::S4 front bumper::12" kicker and JBL amp::::TO COME: 18" BBS RC::painted lowers::PES supercharger