HELP. One coil not working... how to diagnose/fix?

[911teo]

First my set up....

Motec M600 running 993 dual distributor set up.

Problem: engine not easy to fire up and running rough, fuel not burning properly, backfiring.

Symtoms: one distributor is not getting current. I tested the coils and it's not them.

What can it be? The igniter? How do I test that? What else?

I am a bit upset... It took so long for the car to be here and now (I picked it up on Wednesday at the docks) this....

I am so frustrated....

Please any suggestion is welcomed.

Thanks!

[JP911]

Possible that the belt in the distributor is broken? It's always a risk with the 993/964 style twin plug distributors. The easiest way to check would be to pull off both caps and note the position of the rotors. If the one on the left is out of position with the one on the right, then the belt is broken.

[911teo]

Belts are fine. I swapped the wire that went from the coils to the dizzies and the problem followed the coil.

Then I swapped the 2 wires from the harness to the coils and the problem followed the wires, so it's not the belt, not the dizzy, not the coils.

It must be somewhere from the ECU group.