[s-cars] running rough

[Wylie Bean]

First, Welcome to the clubhouse Nick,
Before you go messing with coils for the problem you describe, I'd have a look @ the O2 sensor if the problem is mainly when the car is cold. When was it last changed? Also, have you cleaned the MAF? Slightly rough (not as bad as running on 4-cylinders) or unsteady idle can be caused by a dirty MAF and that's an easy and cheap place to start. It may look clean when you pull the intake hose, but when you take the MAF out and spray it with MAF cleaner (~9$/can) you'll probably see it wasn't as clean as you thought, and the car will run tremendously better afterward.  I just went through a little of what you describe and the MAF cleanse did wonders. The other cold-related issue could be the temp sensor in the back of the head.  Easy to check resistance on it without removing it to see if it's OK. If you do go chasing bad coils, with the engine @ idle you can remove the plug for each fuel injector individually. If the idle gets worse, that cylinder is working fine. If it doesn't change you've most likely found your bad cylinder.  With 1.8T coils it's easy to move that coil to another cylinder to see if the problem moves with it. If it does you know it's the coil and not something else, like a plug.

Good Luck, 

Wylie Bean
90 cq
91 90q20v
92 UrS4
08 Q7

-----Original Message-----
From: Nicholas <applen at gmail.com>
Sender: s-car-list-bounces at audifans.com
Date: Thu, 12 May 2011 23:02:16 
To: s-cars<s-car-list at audifans.com>
Subject: [s-cars] running rough

so i'm new to this list, new to audi and new to urs4 (came from a mk5
GTI). in march i bough a 92 urs4 that's been rs2ed. coil packs appear
to be from apikol (i'm assuming 1.8t coil packs...?).

car has been running real smooth (perhaps a bit rough and boggy when
cold and consuming more oil than i expected... but smooth). tonight i
took it out and it was acting normal with the usual boggyness after
startup but when i stopped at the first light i could feel a
difference in the idle: it wasn't smooth anymore and was closer to 800
RPM than 900+. under load, at lower rpms the engine feels way out of
balance but around 3krpm the engine seems to smooth out and feels
almost normal... but i don't feel like all the power is there or
anywhere above 3kRPM. my guess is that i'm running on 4 cylinders.

can anyone help me with diagnostics on my coil packs? should i just
start with replacing all the plugs? what are some some good diagnostic
tools to have for this engine? other guess/suggestions?

thanks in advance,
-nick
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