Corrado G60 Alternator Problem

[90radog60 10]

A few weeks ago while driving my Corrado home from work it started to loose power. I made it home parked it in the garage and checked a few things that evening. I looked at the air filter to make sure it wasn't plugged (K&N in factory air box) and it looks clean. I turned the key and could hear the fuel pump hum. I then restarted the engine and it ran rough with no power until it finally died. I turned the key to the on position and checked the ISV and it was humming like it should. Just for good measure I took it out and hit it with some carb cleaner. Still no change and will not start now. Next I thought timing, so I turned the engine to TDC and repositioned the distributor. Still no luck. Next I broke the cardinal rule and started throwing parts at it. So far I have replaced both fuel pumps and fuel filter. $300, I replaced the battery (Optima Red Top) $200, I replaced the alternator (I upgraded to 140 amp Bosch) $200.

 

Here comes the weird part. While replacing the alternator I discovered that with the alternator in place and the wires disconnected I could start the car. It runs beautifully while running off of the battery. This tells me that all my wiring is good, distributor and hall sending unit, coil, DIGI are all good. I then hooked up just the big wire from the alternator to the starter, still fires right up. I then hooked back up the blue wire to the alternator and the problem reoccurs once it excites the alternator. I can rev it to 1500 rpm and then it dies and is really hard to get it to start again. I checked the blue wire terminal down by the starter and it looks fine.

 

Has anyone ever encountered this problem or have an ideas as to where I should look next?

[90radog60 10]

Well last night I finally figured it out. Turns out the problem was with my Nology plug wires. I determined that the failure was dielectric breakdown of the insulation resulting in a "Burn through" which provided the high voltage spark a direct path to ground. Once the high voltage had an easier path to ground than the spark plug gap the capacitive effect of the wires created multiple sparks during the duration of the ignition coil discharge time. This voltage was then being passed directly to my alternator.