I have a non starting XJ40 1991..One day I took the car to work and it didn’t start up.. prior to this I had a bad fuel leak from the rail feed I mended that, but soaked a lot of the engine bay, ran for a few days after but then died at work.. I also had a bad power steering leak in the general area of the coil and amp but after it was mended it continued to drive fine.
I noticed while cranking the tach was stuck at 0 and I blamed it on a faulty CPS and let it sit.
2 years later
I drained the tank as much as I could by priming the pump over and over, got about a gallon out (tank was already very empty) , I added 2 more gallons along with a gas treatment.. still no start.
I’ve swapped parts from an 89 at a local yard, being the CPS, Distributor Cap/Rotor and wires, coil, and amplifier.. I cleaned the entire area The aluminum metal plate, Confirmed all grounds are clean and tight.. I get a blue spark from the spark plug boot, I hear the pump prime when I have my gf turn the key (from the trunk) I’m able to feel the rubber feed hose to the rail build a little pressure as we prime but not much pressure at all.. I also hear the Injectors Clicking as I crank, I also can see the tach reading 200 rpm’s when cranking, I swapped relays out and was able to mend a fault AUX light issue that was down to a faulty black 12v relay.. by the way the CPS was spliced and converted to a small style connector.. VCM doesn’t show any codes, battery is new from my XJS V12.
nit sure where else to look, unless all the parts I’ve replaced were faulty, but the car at the yard was in great shape and seemed to be running prior to the accident. All parts looked clean and new.. but I’m truly stumped at this point. Any help is appreciated. Thanks.

 

Ill suggest trying starting fluid. If it runs on a shot it will tell you if your ignition is actually good. I suggest that you still may have bad gas or possibly not enough in the tank. Good luck.

 

Hi Pedro,

One thought that occurs to me is: have you removed a couple of spark plugs to inspect them? Since the car sat for two years, it is possible the plugs have developed corrosion on their threads, which can inhibit the ground path for spark. Another common issue is that if the spark plug well gaskets are leaking, oil can drip down into the wells and seep down the spark plug threads and likewise interfere with the ground path for spark. So even though you have spark from your plug wire to ground, you may not have sufficient spark at the plug electrodes.

Another possibility is that even though you're using a good battery, the voltage seen by the ECM may be too low due to corrosion or looseness on the battery power connections or due to water ingress in the ECM electrical connectors.

It would be worth cleaning your throttle position sensor (TPS) and its electrical connector, and also cleaning the throttle body while you have it off. Also check the integrity of the connections at the mass air flow sensor (MAF), and the coolant temperature sensor (CTS).

Cheers,

Don