Hello all,
So I pulled the car into the garage 2 days ago to do fuel lines and a water pump, was running great. Finished everything up and went to start, nothing. No spark, (pulled a plug) No injectors- (Noid lighted them, no pulses.) I hear fuel pump kick in as it should, everything else checks out. 1990 V12, Marelli.
All the wires look to be in good shape. I haven't gotten to dash yet so I can't tell you if I have tach bounce because it didn't work before. I have to be missing something. Any immediate things that come to mind?
Thanks in advance.

 

I reckon there could be several possibilities, but....

No spark and no injectors often means you lost signal from the crankshaft position sensors.....or they've failed.

Make sure they're both connected and the pick-up magnets are clean. If that checks out, I'd replace both of them. They each serve I different function (I can't remember which does what) but lot of guys replace 'em both at once and forget about for another 20 years.

Others will chime in with other ideas

Cheers
DD

 

The engine will run (POORLY) if the rear crank speed sensor fails but the engine will NOT run if the front position sensor fails.
They are the same part number so I would replace BOTH if that is the problem.

I found this out about 25 or more years ago when I worked at a Jag repair shop.
The engine ran but very poorly, To diagnose I swapped the sensors front to back and the engine did NOT run at all.
I replace the front sensor and the engine ran perfectly.

The original rear sensor failed and when I moved it to the front. the engine would NOT start.

 

Yep, Interestingly not the sensor itself, but found a split in the wire where it was pinched on re-install. Did a temporary fix of the front one and fired right up. Thanks for the help, Will order them in.