Hi, went for a drive in my 1983 xjs he and was running great until i reached hi rpm in first gear once and it suddenly died completley, after haveing it towed home i did some checking. if i can have someone crank it over i can unplug the fuel pump relay in the trunk and it will start run for a few seconds and start to die, i can plug and unplug the relay and keep it runing but if i leve it pluged in it will flood the engine and die. checked the tps with a ohm meater and it seems to be functioning also checked the left and right side fuel pressure regulators neather one has fuel in the vaccum lines. any help would be great. thank you.

 

A couple possibilities for discussion:

I've heard of a few instances where the fuel injector wiring harness was grounding out and causing the injectors...or some of them, at least... to stay open at all times. This would obviously over-fuel the engine. Brittle harnesses are very common on these cars. The insulation cracks off, leaving bare wire exposed. Most of us make new harnesses on or own but you can buy new for about $600

Next, pressure regulators. No fuel in the vacuum lines proves that the regulator diaphragms are not leaking but it does prove that the fuel pressure is being correctly regulated. You need to do a fuel pressure test....which is a PITA on these cars.

Cheers
DD

 

I agree with Doug but I have something to add. Mine is also an 83, and was doing the exact same thing. It would run for a few seconds, then foul out the plugs from over fueling and die. It turned out to be the shielded wire coming from the electronic ignition and going to the ECU. It was cracked and for whatever reason, was telling the ECU to open the injectors wide. I moved the module off the motor and replaced the shielded wire and it ran great after that!

 

Hi, well found the problem the conector sliped of the temp sensor on the head left hand side of engine. I thank there is supposed to be a clip or something to hold it on that seems to be missing. I tied it on with a small wire tie, now it runs like a million bucks again

 

Anyone who'd pay $600 for that easy job of a harness is probably making more then $200 per hour
I have diagram of the harness wiring, so one trip to junkyard for mid 90 BMW injection wiring, some soldering and perfect harness is done!