90q missing on cyl 5...ideas?

[Doyt W. Echelberger]

Hello Dave............Might be a bad wire. Also, make sure your ignition
wire from the coil is pushed down all the way in the neck of the coil. That
connector tends to creep out in small increments, and eventually the
weakest sparker starts cutting out, and the oxygen sensor starts seeing
rich unburned mixture so it leans everything down and then the other
cylinders don't run right, and the owner starts wondering if the engine
will get him home. When you floor it, the mixture gets better and it runs
better, but not right.

Just pull that main ignition wire out of the coil and examine the end, and
then if it is OK, push it back in and all the way down. Might be your only
problem.

The other thing to check is the rubber seal at the distributor, where the
low voltage wires enter the housing. That seal is a rubber block that has
to sit in a slot in the dizzy housing just right, and then you can fit on
the cap. Take off the cap and be sure that seal/block is solid in its slot,
and the low voltage wires aren't under stress.

I'm just telling you what I did to fix a similar problem on my 87 5ktq. It
was running so bad I thought I had bad fuel or needed new injectors and a
new dizzy, and new plugs wires and plugs....bucking and missing and lost
power.....very disconcerting 60 miles from home. Pushed in the coil wire
and readjusted the low voltage wires through their seal, and it runs like a
fine watch. What a relief!   Hope yours is that simple.

That's my best shot, from way out here in cyberland.

Doyt Echelberger
 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Date: Thu, 20 Dec 2001 23:55:07 -0500

 > Current thought is perhaps an electrical problem with the 5th
injector..perhaps
 > effected by water/dampness?
That's one thing it can't be... your injectors have no electrical
"things" to go wrong.
My first thought is that the fifth spark wire is not as good as it
seems. Second is that the dist cap is slightly worse at the contact for
#5, third, that the #5 plug is iffy...
 > The car: 1989 90 quattro
 > The engine: 10 valve, Naturally aspirated. Stock.
 > The problem:
 >
 > Dry weather -> Car drives perfectly fine.
 > First Snow/Freeze -> Car was fine, halfway home car began to idle like
it had a
 > REALLY lumpy cam in it. Hit the gas...car almost dies, backfires in the
 > manifold/downpipe...then suddenly revs up and away you go. Keep it above
 > 3000rpm otherwise car drives like it's missing.
 >
 > At home I checked the wires, plugs, cap and rotor. Cylinder 5 (closest to
 > firewall) has spark, but does not have a combustion reaction. This is
evident
 > as car idles no different if you pull the 5th sparkplug wire. It idles
rougher
 > if you pull any other wires.
 >
 > TIA
 > Please reply directly, as I'm not recieving list messages at the moment.
 > -Dave
 >
 > ---------------------------------------
 > 89 90q 300,000km!!!!!!!!
 > http://home.the-wire.com/~spokes
--
Huw Powell
http://www.humanspeakers.com/audi/
http://www.humanthoughts.org/