[A4] Coil Pack Help
Pbadore at aol.com
Pbadore at aol.com
Wed Jul 6 09:54:59 EDT 2005
The ignition control module was used on AEB Audi and Passat 1.8l turbo
engines from 1997 model year through part of the 00 model year. After that the
function of the ignition control module was integrated into the individual coils.
Your A4 doesn't have a nice easy to change ignition coil pack.
The problem that you are describing seems like too rich a fuel mixture. I
have had a problem with
similar characteristics which was caused by having a completely refueled car
with a full tank of gas that then was left to sit in the driveway for about a
week. The summer sun caused enough vapor pressure to flood the engine and
cause it to run on only 2 or 3 cylinders for a few a couple of minutes.
If your A4's coolant temperature sensor is failing it is possible that the
engine ECU thinks the temperature is low and then overfuels the car. The coolant
temperature sensor is easy to change
and a lot of them have failed--but usually it is only the gauge part of the
sensor function. The next
component that I have seen failed intermittently is the evaporative control
valve which vents the fuel tank vapor to the engine after the engine is warmed
up. If the valve sticks open then the vapors from the fuel tank venting will
collect in the intake manifold and make the engine run rich. Also an oxygen
sensor that sends a wrong signal can cause a similar problem. And I would guess
that a manifold pressure sensor that malfunctions indicating boost when there
is none would do the same. I have not had an A4 do this but my 90 Corrado G60
supercharged engine with a bad MAP sensor would completely foul out a new set
of spark plugs in less than two minutes of running. With a number of
possible reasons (there are more) for rich running you need to read the fault codes
and measuring blocks with a tool like VAG-COM otherwise you will be in the
"cut and try " mode of repair. Lastly, how old are the spark plugs in your A4?
Sometimes the deposit build up on spark plug electrode insulators can cause
random misfiring when the plugs are not at their operating temperatures.
More information about the A4