My girlfriend's 1996 Golf (4 cyl) has become unreliable in wet
conditions. So far, mechanics have replaced the distributor cap, spark
plug wires, and ignition coil in attempts to fix the problem. They also
replaced or checked the spark plugs. These all seemed reasonable to
replace given the age of the car.

During the last heavy rains this weekend, the car lost some power and
the check engine came on. I'm guessing that this is an ignition problem
since it seems to only happen in the rain. By Monday morning the check
engine light has gone out and the problem appears to go away.

Besides the replaced components, what else can be checked? Is there
anything particularly susceptible to problems with these engines?

Thanks!

In rec.autos.makers.vw.watercooled, Greg wrote:

Run the engine in the dark. Let your eyes adjust to the dark. Use a
spray bottle to spray a fine mist around your engine, and watch for
arcing.

Greg wrote:
What code was stored when the 'check engine' light went on?

--Winston

"Tom's VR6" <no (AT) mail (DOT) please> wrote

The CEL might also be of some help but not necessarily. Sometimes they're
triggered by a misfire and sometimes the faulty component will cause the
trigger (it depends on if it came on because of the faulty component (most
useful) or because of a symptom caused by the faulty component (the misfire,
which is just a symptom). I'm not sure how comprehensive CELs are on a '96
but it might give you the cylinder number of the misfire. If it's that
detailed it might help. Bottom line..get the fault code read and that could
at least point you in the right direction.

"Greg" <greg (AT) no (DOT) spam.please> wrote

No, it doesn't have to be an ignition problem, it could be a timing problem.
I had the exact same problem with my 1995 Jetta GLS. It turned out to be
the Hall-effect sensor on the distributor. Apparently you can't replace
this part individually so I had the distributor replaced. Fixed the car
right up and there were no more problems with fog, mist, or rain causing
power loss

With this Hall-effect sensor problem, I always dreaded driving the car after
letting it sit outside on a rainy evening, it would drive like crap for the
first 15 miles or so on the following morning. CEL light would come on,
power dropped noticeably, sometimes the car would just die upon putting it
into first gear from a stoplight.

Whatever the problem is, please post your solution on this thread when you
get it fixed to help other with their Jetta/Golf troubleshooting woes.

In rec.autos.makers.vw.watercooled Pierre_St_Germain <pierre (AT) yahew (DOT) com> wrote:
The hall effect sensor on the A3 is used checking cam position for the purposes
of adapative knock control and sequential fuel injection. Unless the car shuts
itself down because it decides the timing belt is slipping, it shouldn't have a
substantial impact on the drivability of the car. It also seems very unlikely
that you'd have a water problem with the hall effect sensor without having a
bigger problem with water getting in the distributor and messing up its
functioning.

Probably because water was in there causing the distributor not to work
properly and resulting in misfires.

I agree with other comments. It should be easy to determine this sort of
problem by just using a spray bottle full of water in the dark. Also, a 96
car should be OBD2 equipped so the diagnostics are good. Use VAGCOM or
another good scan tool and see what the computer says.

dan

I have seen "aftermarket" new ign. coils go bad within 1 week. :-)
I only purchase from the dealer now!
What about the distributor rotor? Only Bosch rotors please!!! lol

Does this car have an automatic transmission? If so some wiring may be
affected by the rain also and could cause the loss of power symptoms.

You need to let us know what the DTCs are telling you. ;-)
later,
dave
(One out of many daves)


"Greg" <greg (AT) no (DOT) spam.please> wrote

Did the engine die while you were driving the car? If so, is it
possible the engine was soaked from driving through a deep puddle?

I had a similar problem on my mk3 gti 16v. When the engine was cold and it
was damp, the engine would suddenly lose power and the car would start
jumping, or it would hesitate slightly. I had it checked and found out that
the main HT lead from the coil to the dizzy was slightly cracked and may
have been arcing. Also, the black plastic housing around the dizzy cap was
removed as this can cause problems in damp conditions. Since these changes
the car has been fine.


"Greg" <greg (AT) no (DOT) spam.please> wrote