I believe this is actually an electrical problem and am sincerely hopeful someone is knowledgable enough to help because I am in quite a bind.

I bought an 1987 Vanden Plas XJ6 which had been wrecked and stored back in 2002. I've brought her back from the brink, replacing all damaged componants and personally doing all corrective body work myself. Mechanically, everything appears to be sound - unless I have overlooked something - but I have two problems which keep me from putting her back on the road.

The first is perhaps minor problem, but possibly connected. Beneath the glove box, just behind the fuses, was a white plastic piece interposed between two wires (purple and white in colour), the componant was about the width and length of my pinky before it melted due to a shorted circuit. On the right hand side of the componant the lead is live (regardless of key position) and on the left hand side it is always grounded. For the moment I have simply clipped the connection until I can properly trace the wire and find where it leads and what it has grounding itself upon.

My main problem has to do with the fuel delivery system however. When manually primed, the engine runs beautifully. However, it will not run without being primed. I have managed to discern that the fuel pump has no power leading to it. Were that the only problem, I could simply forge an alternate route of power but have found that even when power is given to the pump, the engine does not run. I have followed the flow of petrol and established that it stops at the injectors. It is possible the injectors might be clogged or inoperative, but with the fuel pump also unresponsive, I am suspicious that there may be some link between the two problems and am desperate to discover what it is. I have put so much time and money into this project, I simply hate the idea of handing the car over to someone else at this point when I seem so close to completing it myself.

 

I am not an electrical wizard but I'd like to put out a conjecture. Does the 87 VdP have a "fuel cutoff" switch located in the area of the footwell? It's a unit that, when a collision occurs, trips and cuts off fuel to the fuel pump to eliminate the possibility of a fuel fire under pressure. I know my '97 has one. I also know that my daughters Ford Explorer had one. It's something you can reset, too, should it trip under a minor collision.

This is just a complete guess on my part. I don't have the manuals for your car. You might want to check that this was part of the circuit, however, because if it was, that might be the reason there's no power going to the pump when everything look proper.

Good luck with that. In the very least, I'd be trying to figure out that the melted component is!

Rome

 

Quite right friend! It turned out to be precisely that. The burned out componant was a diode completing the circuit for the passanger side door light to operate. The inertia switch wasn't in my Hayne's book, but after looking around a bit I found it - below and to the right of the glove box, sitting adjecent to the hinge.

Mechanically, constructionallyand electrically my Jag is now one hundred percent.

Thank you.

 

Excellent! I was hoping for you that it was somthing "simple" like that. There's nothing worse than having to track down weird electrical problems.

Consider that my Christmas present to a fellow Jag owner! LOL

Rome