I bought a non running 92 xjs V12 Convertible back in July. Got it running it has a bad ignition switch. I put a push button start on it and it ran great. I took it on its first actual drive got one block and it stalled and wouldn’t restart. I replaced the TPS and CPS. The CPS was actually burnt up. I also found a big hole in the distrubotor cap. I replaced the cap, rotor, spark plugs and plug wires. I am getting fuel, I have spark to the plugs. It still will not start even when I spray some ether? Losing my mind!!!!! Any ideas? Any Harlow is appreciated! Thank you

 

Bugga.

Marelli and me, not a good match, never owned one, but common questions I will ask from what I have gleened on here.

Replaced the CPS, which one?, there are 2. One up front, the 2nd tucked in behind the oil filter area. Never looked, just what I read.

You have fuel sweet, but are the Injectors triggering while crarnking, maybe that 2nd CPS is the pulse signal for them?.

The fact you spray ether and NO BANG, suggests no or very weak spark inside the cylinders.

Check the engine earth strap fiasco around the LH engine mount, many a dead Jag has been from that nonsense.

CTS (Coolant Temp Sensor) on the B Bank thermostat casting. Cheap as chips, and NOT unique to Jag.
Reason, running V12, unplug CTS = DEAD V12, its that simple.
Cheats way, unplug CTS, bridge the terminals IN THE PLUG, try again. That fools the ECU into thinking its a hot engine.

 

Hi Ltlcar

Looks like you almost had a 'Marelli Fire' and you were very lucky that your Car didn't Burn to the Ground! (Seriously Yes! that could have easily happened) and so whatever you do don't drive her until you've got her fixed

Burning a hole through the 'dizzy cap' is usually what happens just before your Car goes up in Flames, as you notice a Sudden loss of Power when one of the 'Banks' shuts down, while the Bank that's still running, is Pumping Raw fuel into the Red Hot Exhaust Pipe of the one that is not

This Exhaust can hold about a Gallon of Unburned Petrol, assuming your Car is not already in Flames and so to say you were lucky is a bit of an understatement, where more often than not this is caused by poor maintenance like for instance not replacing the Plug that is beneath the Air Con Motor

The Chances are that one or both of your 'Cats' have started melting and have got blocked, so that would be the first place I would look and is probably the reason why she won't start now

 

Thanks for the help, I replaced both of the sensors fly wheel and the one in the front. I will definitely check the ground strap. Thank you.

 

Hi Orange Blossom, you are correct about going up in flames. I’m lucky it didn’t go up! I will look into the cats, cuz it seems like it should start but won’t. Thanks for your help. I am determined to get this car running again.