coil problem.

[jeff_wee]

my bug will stop running after i drive my bug a bit then it will not turn over and start but if i wait awhile then try it starts up, would it be my coil, cuz it was really hot today when i was looking at it.

[NOVA Ghia Owner]

Jeff:

The coil will not have any impact on the car turning over.  This will be the starter circuit.

It sound to me like you have a hard start or hot start problem.  Do you have a Hard Start Relay installed? The problem is due to the peculiar nature of the VW wiring where the battery is not near the engine compartment. Current to start the car must go from the battery all the way to the ignition switch and then back to the starter. Its a long run of wire compared to what you would typically see in a car with the engine and battery mounted in the front of the car.

Over time, as the wire ages and electrical contacts become corroded, resistance builds in the wire. This is magnified in a hot climate where heat further increases the resistance. As I recall, the problem first appeared in California years ago as a result of the warm climate (and probably also a high concentration of VWs). It is further magnified by the air cooled design of the vintage VW engine where there is no liquid cooling system. The starter is tucked way up by the engine/transmission and can act like a heat sink.

Putting in a relay helps to solve the problem as the relay acts like a switch and the starting current does not have to travel all the way forward and all the way back. Its right there via the short run from the battery.

The following link from Wolfsburg West's site is an excellent reference and provides some good illustrations.

http://www.wolfsburgwest.com/wired/wired_03_01/wired_03_01.htm

[Dennis Flora]

When you say it won't start, do you mean that it turns over fine, but just doesn't fire up ???  or do you mean that it wont even crank over the engine ???  Dennis