Help!
Background:Passat G60 Syncro Wagon
While driving or just at rest idling, the car will just turn itself off. I don't lose electrical (ie. windows, dash, stereo, etc.) but I do lose the power-assisted steering. It really scares the bejeebuz out of me when I'm driving as it isn't like I'm just releasing the throttle, the tach drops to zero immediately like the car has been turned off. It has happened in all types of weather and on short and long drives. It can happen 5 minutes after I turn on the engine or 2 hours after I turn on the engine. I have taken it to 4 shops now, the last being the local dealership. Have had lots of parts replaced with no luck. The real pisser is that everytime I get it to a shop, the car decides to run fine. (Just like that singing frog....) A couple of days ago, the dealership replaced one battery clamp, adjusted my fuel/air ratio and made sure that all of my ground wires from the ECU and from the battery were good. Today, my car died on the way to work. Was going to get it towed to the dealership but the car decided to fire up again when the tow truck arrived! The tow truck followed me to the dealership where I dropped it off again. And of course, the problem would not manifest itself. Arghh! The most recent theory from the dealer is that the hall sender may be faulty. Just so you know, a list of parts that I have had replaced are: fuel pump (minus new sending unit), power supply and fuel relays, fuse panel, and ignition switch. Oil is changed regularly and air filters, fuel filters, and spark plugs are changed at the recommended intervals.
So, finally was able to do some diagnostics on my car while it was dead. Has died frequently over the last 2 weeks, (once while I was trying to off-load from a ferry....that was frustrating to say the least.) While dead, tested for spark at the ignition coil from the ignition wire and no spark. Suspect a faulty Hall Sender so as per the Bentley manual, tested for power and proper ground going into hall sender through the harness attached to the distributor. Got 12V across the 2 outer connectors (Bentley says should be at least 9V) so that seems to be OK. Test the hall sender function by probing the middle connector of the hall sender harness (while it is connected to distributor) and touching the battery (+)terminal while cranking the engine. With the ignition at start position, read ~1.6V but while cranking it decreases to 1.52V. What does that mean? Bentley says to use a LED tester but I figured that a multimeter set at 40V range should do it, right? Anyways, Bentley says the LED should flicker while cranking. I figured the multimeter should show a fluctuating reading if the sender was working properly. Eventually, the car started up again after taking off the distributor cap and cleaning around the sender (don't know if this did anything or if the car was just ready to mysteriously start again). I did the above check of the hall sender unit again and when the ignition is turned to the start position, I read 12V between the middle connector of the hall sender harness and the battery (+) terminal. I did not check it while cranking as I was scared I'd damage my meter. Anyways, have read lots on the hall sender on the VW newsgroups and how it has caused unpredictable intermittent loss of power to the engine. Based on the above diagnostics, I am even more determined that it is a faulty hall sender unit. Am I on the right track? Is there anything else I can do while it is dead to ensure that it is in fact the hall sender?
Also, where is the power stage on the ignition coil? Bentley shows a separate attachment on the side of the coil (looks like a capacitor of some sort) whereas I don't see it on my coil. Are g60 syncro coils different? What I do have is a connector attached to the 1(-) terminal on the coil with a single wire coming out of it.
Thanks.
Ernie stage 2 wagon 159000 km Victoria, BC