XJ-S 4.0L 5speed Won't Start In the U.K.
 

Hi All
Can anyone tell me why my 4.0l 1992 xjs will not start.
Turns over but there is no fuel or spark.
I have changed the crank sensor at the front but its still the same. The last time I used the car it was fine and parked it and all was well. About 3 week later it would not start.
This happed about 2 months ago and as I am restoring another car I have not had the time to look to closely at it. I have been told it may be the Main relay but where is it.
Any thoughts..

I may be having a similar problem. My car has taken to quitting intermittently.

Symptoms include a flashing MIL lamp (check engine)
When the MIL lights the fuel pump relay engages.
According to the manuals the ECU goes through a startup routine and then engages the fuel pump and checks sensor state. It's hard for me to tell but it seems the ECU is failing in the startup routine. I'm not sure how to tell though.

What I was able to do for a while was switch the ignition off and then to ON. If the MIL was lit the engine would fire. If the MIL was off then it wouldn't. You might try switching the ignition off/on and check the state of the MIL.

I've replaced the Fuel Pump, Fuel Pump Relay and Crank Position Sensor.

I sure would appreciate any guidance. I'm going to try swapping ECUs but I imagine that'll result in my having two perfectly good ECUs and again not resolving the problem. I've been all over the car listening for relay chatter since the strobing would, you might think, allow me to better track down the failed component. I've been inspecting the electrical connections as well with nothing overmuch to show for it.

Oh yes, one other thought on your car. I had a similar problem once and the "gearbox fail" lamp lit. Turns out the problem was that I had disturbed the inertia switch when installing a replacement stereo. Pressing the reset on the switch resolved the problem. Without an automatic transmission in your car the symptoms might be different. Try resetting the inertia switch. It should be mounted under a cover on the passenger side A-pillar. The reset is through a finger size hole in the top.

Hmmmm.

-Sodium

1995 XJS 4.0 Convertable.