Post: #1

Today a couple miles from home on the way to work my car bucked a few times then quit running. Got it started a couple times but it would die after a couple seconds. Then it would only run with the starter engaged, and die as soon as I came off the start position. Fortunately it was mostly downhill to my house, and I was able to make it home. Picked up my 72 and made it to work on time. Haven't had a chance to troubleshoot, and am hoping someone recognizes the problem and steer me in the right direction.
One thing I noticed when it was starting to die the tach jumped up a couple hundred rpms without the engine inceasing in speed. Thanks.

Post: #2

When the key is in the run position, do the warning lights come on as per normal? Reason I ask, is that maybe your ignition switch failed, so it only provides power to the fuel system when the key is in the start position. Another possibility is a bad or disconnected ballast resistor... Supposedly, if the resistor is disconnected, the engine will run only when the key is in start.

-J

Post: #3

(07-28-2012 01:42 AM)Blue245Ti Wrote:  When the key is in the run position, do the warning lights come on as per normal? Reason I ask, is that maybe your ignition switch failed, so it only provides power to the fuel system when the key is in the start position. Another possibility is a bad or disconnected ballast resistor... Supposedly, if the resistor is disconnected, the engine will run only when the key is in start.

-J

Those are both good possibilities, I'll check. The ballast resistor and ignition switch are original equipment on a car pushing 400K. Would it hurt to bypass the resistor to check? The wiring harness has bee replaced. I have to work 12hr days thru Monday so I don"t have a lot of time to troubleshoot. Before this happened, the car would cut out momentarily under full boost. One time it quit completely but restarted in a few minutes. I thought I had shorted out wires around the starter, because moving then let the car restart, or it could have just been a coincidence. I have the green manuals that I will take to work today to check other possibilities.

Post: #4

I did a quick check this morning and the car started right up of course. The dash lights are on but may not have been yesterday. Leads me to believe something is overheating. I don't know if the ballast resistor does that, but I did have an incorrect coil act the same way some years ago. The coil may be failing. 12 volts to the coil(in the start position) may fire it, but the reduced voltage thru the resistor may not. The coil is a master blaster that is several years old. The earlier problems missing under boost could be a weak spark blowing out .

Post: #5

Sounds like something an ignition switch could or would do.

Post: #6

That might do it, too. Could always try a Bosch blue coil for an air cooled VW (think it's Bosch 00012 or 119 027) and see if problems crop up again.

-J

Post: #7

(07-28-2012 12:51 PM)Blue245Ti Wrote:  That might do it, too. Could always try a Bosch blue coil for an air cooled VW (think it's Bosch 00012 or 119 027) and see if problems crop up again.

-J

I have a spare blue coil that I will give a try when I have time off. Can't tell anything for sure until i can test. I also have a toggle switch that I can put 12 volts to the ignition switch side of the ballast resistor to see if the switch is cutting out the power. everyone:thanks for all the advice!

Post: #8

Could be a ballast resistor or the coil having a high-temp breakdown. Never had a car with a resistor myself, but I remember the parents' old Dodge van that made it jsut fine from the house to the store, wouldn't restart. Cooled down and it made it home, wouldn't restart. A new ballast and all was well. I've also had issues with a coil having a high-temp breakdown on the wagon. Had some funky issues under boost, coil checked out fine cold, but hot the secondary side was about 3-4k outside spec. New coil and all was well.

Given the funky tach issues as well, I'd probably guess something on the ignition side rather than in the switch, at least for starters. See if you can grab a spare switch, coil, and ballast, plus your AAA card and go drive it. When it fails, swap the easy stuff first one by one.