S4 / RS4 (B5 Platform) Discussion Discussion forum for the B5 Audi S4 & RS4 produced from 1998-2002

Cyl 4 misfire, Boost control below threshold, limp mode while logging... Just replaced coil pack...

Thread Tools
 
Search this Thread
 
Old 06-23-2008, 08:50 PM
  #1  
Junior Member
Thread Starter
 
Stonediggity's Avatar
 
Join Date: Mar 2005
Posts: 1,196
Likes: 0
Received 0 Likes on 0 Posts
Default Cyl 4 misfire, Boost control below threshold, limp mode while logging... Just replaced coil pack...

Hey all - been a while since I've been over in this forum, spending all my time in the Rocky Mtn Regional board.

I've had a CEL for a week or so for a Cyl 4 misfire. I figured the easy answer was coil pack, the harder answer was injector... I dropped in a coil pack tonight, fired her up and she ran smoothly, but after a few pulls I started getting intermittent misfires again... Injector?

I was also going to run some logs for Tony @ EPL to see about some overboost I've been noticing and while running a log of 114 and 115 in 3rd from 2k - redline I go into limp mode on the first pull with a code of boost control below threshold (not sure the wording, and I don't have my VAG computer here).

So I figure that means N75 kaput?

Is there any alternate explanation for the Misfire besides injector if the coil pack didn't do it?

Thanks!

- Aaron
Old 06-23-2008, 09:39 PM
  #2  
AudiWorld Member
 
2fst4u2c's Avatar
 
Join Date: Feb 2004
Posts: 311
Likes: 0
Received 0 Likes on 0 Posts
Default

wouldn't the "easy" be the plug? if not plug or coil, check ignition amp before injector...
Old 06-24-2008, 06:57 AM
  #3  
Junior Member
Thread Starter
 
Stonediggity's Avatar
 
Join Date: Mar 2005
Posts: 1,196
Likes: 0
Received 0 Likes on 0 Posts
Default

I'll swap the amps tonight - thanks, I apparently did a **** poor job of STFA
Old 06-24-2008, 07:47 AM
  #4  
AudiWorld Member
 
2fst4u2c's Avatar
 
Join Date: Feb 2004
Posts: 311
Likes: 0
Received 0 Likes on 0 Posts
Default

good luck, post your findings...
Old 06-25-2008, 05:26 PM
  #5  
Junior Member
Thread Starter
 
Stonediggity's Avatar
 
Join Date: Mar 2005
Posts: 1,196
Likes: 0
Received 0 Likes on 0 Posts
Default Replaced all 6 plugs and switched the amps. Didn't fix it... I guess it's time for an injector.

I replaced all plugs with NGK bkr7e gapped to .030 and swapped the amps and cylinder 4 is still mis-firing at 1-2 misfires a second. N75 is on order, maybe I'll throw an injector in and hopefully that and the N75 will fix my issue.

Any other potential causes you can think of?
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Omega Supreme
A4 (B5 Platform) Discussion
9
02-27-2008 04:43 PM
PSYC0TIC ONE (USMC)
S4 / RS4 (B5 Platform) Discussion
20
01-13-2007 09:01 PM
Etek
S4 / RS4 (B5 Platform) Discussion
5
09-05-2006 06:45 PM
üBER.QIK
S4 / RS4 (B5 Platform) Discussion
3
04-18-2006 04:11 PM
tppatron
A4 (B5 Platform) Discussion
5
03-18-2004 07:41 AM



Quick Reply: Cyl 4 misfire, Boost control below threshold, limp mode while logging... Just replaced coil pack...



All times are GMT -8. The time now is 12:04 PM.