I read in a past thread a week ago the quick reference whether my '89 V-12 is Marelli or Lucas systems is if the distributer cap has TWO center coil wires it is Marelli.
Can anyone else confirm this to be fact? I definitely have two center plugs, side by side with one feeding three white wires from it and the other coming from beneath the ignition coil.
What is the preference, or better setup? -I've read pros/cons for both systems.

 

Yes, two coil wires into the cap = Marelli. You'll also have two stacked coils and two control modules above the radiator.

Marelli is fine if the rotor doesn't burn thru. Insulate the rotor with silicone, make sure the plugs are good and gapped at .025", and make sure the the plug wires are good.

There are other Marelli failure modes....module or coil failures....but rotor burn-thru is the most common.

Cheers
DD

 

Thank you Doug,
Can you please elaborate just a tad your comment to Insulate the Rotor....Do you mean the Rotor 'button' inside the distributor?- Put silicone where?

 

A dab of silcone sealer on the inside of the rotor itself, where it slides on the distrubutor shaft. Some guys trim down the length of the rotor as well....or something like that. The details are probably in here, along with tons of other XJS info:

Kirby Palm's Jaguar XJ-S Help Book


Cheers
DD

 

Easiest way to tell a Marelli is the 2 orange ignition modules on the radiator top support