Cool very glad to hear you got it running! Sorry, I didn't know there was that much difference in the 2 ignition systems. Mine obviously has the Lucas system.

Jack

 

Congratulations Steve.

 

Steve, glad to hear you got it running! I too, bought a 1989 not running. The shop that had tried to repair it, had even bought a new wiring harness and that didn't do the trick either. Mainly because the guy that built the harness wired the rear crank sensor backwards. Yes, it does have polarity. Anyway, during my discovery of how the Marelli system works, I also checked my air gap. The "sensors" need to be about .020 away from the flywheel and the damper fingers. It isn't easy to do, but I would encourage ALL Marelli ignition owners to do this. The "sensors" are nothing but a magnetic hall effect transducer. As the magnet breaks down over time, it eventually sends a incorrect signal to the computer, and well, you bought one.

The only way I found to reduce the air gap, was to actually file the mounting boss on both of my sensors, put the sensor in, the check with a feeler gauge, and file again. The front sensor is pretty difficult, in the I found that the timing fingers on the damper are slightly different. I just filed the mounting boss to get the air gap to .020 on the closest one, and the other two just had to be what they were. (seems like .024, ,.027?)

I say all of this to give credit to my long deceased grandfather, Cecil Burris, who took the time with me as a child, to teach me that anything a man made, another man can repair (usually). His quote was "figure out what makes it work, and fix what isn't working". I will never forget working on neighbors lawnmowers. He wouldn't charge for repairs to his neighbors, but one of the most simple repairs was to put a sheet of paper between the magneto/coil, and then loosen the magneto/coil screws on the old Briggs and Stratton mowers. This would cause the coil to pull itself to the embedded steel in the aluminum flywheel, thus closing the air gap. This would cause a poor running mower to have the greatest spark possible, assuming the coil was good.
Hopefully I haven't rambled on too much, but good luck with your Jag, as it sure looks to be a great buy.

 

Found my original post from last year when I bought the car; thought I'd update. Today I FINALLY got the alignment "done properly" after 2 other shops failed to do so. YEAH she drives straight "hands free". It could use a tad more caster but for now I'm happy as I can finally "feel the joy" of driving her.
It has been a long road to get to this point. She has 17" Revolvers now with new Continentals; 235/50-17s with 5mm (.020") spacers up front. Since purchasing the car I have done the following: Under bonnet new parts...cap, rotor, Ht leads, spark plugs, injector harness (from parts car), injector fuel lines, cam cover and intake gaskets, (vee cleaned), radiator cleaned with drain tap added, twin electric fan unit, smog pump deleted, Bosch alternator deleted, GM 140 amp alternator in place of smog pump, new complete set of coolant hoses. Mics wiring tidy up with some new connector plugs as needed. Rear chassis new parts: diff stub axle bearings and seals, drive axle/ half shaft u-joints, replacement HUBS (from parts car) as each of mine were cracked; with new inner/outer bearings, new sport trailing arms (with tabs for future sway bar). New front and rear brake rotors, pads and rebuilt calipers. Complete RH door harness and locking actuator replaced with one from parts car, as the central locking harness had a short and locking actuator was broken. Binnacle lights replaced with "Super Bright" LEDS, and dedicated ground wire to dash added. Paint-less dent repair guy removed 50 dings/dents. Other misc little repairs adjustments etc. To Do List includes: erratic speedo---parts car Speedo interface box (in the boot) that the transducer plugs into, better than before but still drops out? Replace entire ABS harness with parts car harness. Short between the two wires on RH side somewhere between connector to the wheel sensor and ECU connector in the boot. Weld in new driver floor pan in front of seat where a clogged AC drain rotted it out (pan already purchased from SNG Barrett). Those are the remaining major repairs needed at this time that I can think of.

 

Amazing!!!