92 Golf Loses spark

[Problemsolver]

Lets see if anyone can help with this problem. I am a mechanic with 15 yrs. in the field and have yet to be faced with a problem as confusing as this.
92 Golf GL, 1.8L federal, 5spd

The following parts have been replaced:
Full tuneup, with coil and hall effect sender, Ignition control unit, (in desperation) a test ECM, intake air sensor, and a fuel pump relay.
Alternator and battery.

Ok this is the senario. I purchased this car about 6 months ago the original owner had prolbems where it would die after a bit of driving then after sitting for about 30-60 minutes it would start up and run fine.
I diagnosed it and replaced the alternator as it was only putting out 9-10v at high idle and I put a battery in it as it was not holding a charge overnight. I drove the car for 3 months with no problems even went on a 500 mi trip with it not 1 problem.

Then in October we had a big rainstorm rained for 4 days off and on. This is when I had the first problem. I got to work (it was raining) as soon as I parked the car it died and would not restart. I let the car sit for 4 hours it started and ran fine for about 8 miles.

Ever since then the problem has been getting gradually worse. I have spent the last month troubleshooting and replacing possible bad parts. This is now ticking me off not to mention getting expensive.

The car will now start and run for 60sec then dies. I let it sit for 15-30 minutes with the key off and it will restart and run for another 30-60sec.

I have traced the problem to be that it is losing spark. The hall sender is loosing power there for not sending the pulse signal to the coil.

I have a subscription to All Data and have followed every diagnostic I can find that has to do with the spark control but can not seem to find the actual problem.

So there you have it.

Looking forward to your solutions. Thanks

[boschmann]

I've had similar problems caused by the fuel pump relay's internal fuse block connections. Did the coil ever go bad & start acring? I've also had an arcing spark damage the coil's wiring harness. How about the distributor's wiring harness connector?

[Problemsolver]

Well as complicated as this may seem I have solved the problem. (hence the name) The Digifant II system in this vehicle has a relay for the Digifant control unit. Which is powered by the key from terminal 30 to terminal 87. Although the relay was activated by the key and did not deactivate when the vehicle died (click____click) it would cut the power to terminal 87 there for shutting down the power for the Digifant control unit inturn cutting power to the hall effect sender.

If you are having a similar problem with the engine dying intermittently you can follow these troubleshooting steps avoiding costly parts replacement.

1- Locate the relay pannel on the left side under the dash.
2- Remove the retaining clips for the relay pannel.
and drop the pannel.
3- locate the relay on the 2nd row from the bottom 3rd relay to the left.
4- This is the Digifant control unit relay.
5- Remove this relay.
6- Build a jumper wire with spade connectors on both ends.
7- Plug this wire in to the corosponding recepticals to the relay #30 and #87 (bottom and right on relay pannel)
8- Start the vehicle and let it run. Test drive.
9- Purchase new relay and replace old one.

NOTE: I do not recommend you drive the vehicle too long with this relay bypassed as it could cause other problems and or a severe melt down.

Please only use this guide for diagnostic purposes only.

By the way this is AKA the ECM relay OEM pt# 357906381 I have no t found an aftermarket # yet.

[Problemsolver]

Boschmann, Thanks for the speedy reply and to answer your question.... I did break the cap pulling the coil wire out which was causing arching and I think it fried the hall effect sender because it went bad on me a few days ago now that you mention it.

But I also have a rule to start with the cheapest part and work your way up.

The biggest problem was that I was not familliar with VW components and did not know there was a relay for the ECM.

Thanks again.