> > I think your mechanic may be right this time.
> A defective coil will work when the engine is cold for a while.
> When the engine is hot and the coil is at operating temp, the weak or
> failing insulating yields and the coil loses its abilitilty to act as
> an inductor, thus no sparks. When the coil cools down it will function
> again since the insulation self-heals itself temporary.
> > The orange spark is a sign of a weak volatge.
> 					Terry Tan
I just discovered this problem also (although not on a VW). A faulty 
coil resistor caused the coil to overheat on my Dad's Chev 350 boat 
engine, causing it die after 10-15 minutes of cruising. Coil was too 
hot to touch after stalling, but other engine coil was fine.
Can anyone say of the VW system uses a resistor, or is this an old 
fashioned method? If VW does has a resistor, could the same type of 
failure occur, ie: cause the coil to overheat?