I was called out to help with a friend’s car the other day, a 1997 Jaguar XJ8 3.2 litre. It was driven onto the lift for rustproofing (Fluid Film) and afterwards it wouldn’t start. Actually, it wouldn’t budge at all, so first I had to tell them how to get the gear lever out of Park…
Somebody suggested that the ECU was fried, so I brought a working one, but that didn’t change anything at all, so I put the old one back in.
I was told that problems - although not specified - had arisen previously out of not waiting until the ‘System check’ message had disappeared until hitting the starter, which tells me that something’s wrong as, In my experience that shouldn’t matter on a healthy car.
The displayed messages (please see video below) loop, and when the key is turned to the start position, it doesn’t engage the starter at all, but the ignition lights dim slightly (battery should be healthy (green dot to be seen) but was only 12,4 volts when I measured it). The battery has been charging overnight, but it was no change when they tried this morning.
I also thought about the obvious ‘dodgy earth-connection’ scenario, so I fed a massive ground cable from the battery to the engine, to no avail, so I removed that. Measured multiple points in the engine bay, and found good earth connection everywhere…
The remote control didn’t work at all, so I tried the re-program procedure; no chirp after flashing the lights 4 times, so it never entered programming mode.
One thing I noticed that our own XJ8 doesn’t do, is that the temperature gauge rises and then drops when the ignition is turned on.
Any wisdom that can help us with this case is greatly appreciated!