I’m the new owner of a very interesting '89 XJ-S. The car has been kept in great conditon and is quite stunning to say the least. Black on black with later model wheels, hidden driver lights behind the grille, AJ6 Superenhanced ECU, quad throttle bodies and a free-flow exhaust. Who knows what else. The previous owner unfortunately is no longer with us so I can’t confirm any additional mods.
The car came to me through a brief owner who had purchased the car at the gentleman’s estate sale. He was told the car ran when parked 7 or 8 years ago. He proceeded to go through the entire fuel system including boiling the tank, running new lines and of course a new pump, filter and accumulator.
He was unable to get a spark and or injector signal and gave up on the project. That’s when the car to me.
I immediately started checking all the usual stuff including Crank Sensor and Speed Sensor. They Ohm out fine. I have access to a 1988 (Marelli car as well) parts car. I’ve swapped out the power modules, Marelli and Lucas ECUs. I still don’t get any spark and or injector signal. That’s until after some more fiddling with wires and ECUs, etc, I went to crank it and I could tell the engine tried to fire due to the starter slowing down and speeding up. Almost as if it were out of time. I hooked up my light to a spark plug lead and installed a noid light in one of the injector plugs and lo and behold I had something. A very, very faint signal on the noid light but a signal none the less. After some more fiddling, I lost both signals and am back to square one. I was able to reproduce the low signal / crank situation once more back have not since.
Can anyone shed some light as to what may be going on?