1994 Jaguar XJ40 6 cyl Two Wheel Drive Automatic 86000 miles
I have an electrical problem where, from time to time, the fuel pump does not activate when I first try to start the car. I have 12 volts to the fuel pump relay. I have continuity all the way to the pump from the relay (about 3 feet). I have jumped the relay directly to the fuel pump power in wire and the pump does not run. However, if I jump that wiring directly from the battery, I get the pump to run. It is as though there is not enough voltage to initially get the pump started.
Once I jump the wiring directly to the battery for about 1 second, all the problems seem to go away and the car will start and the electrical system operates as it should. Ie. Jumping the system from the fuel pump relay activates the fuel pump.
Some times I can go for several days before the problem resurfaces. I then jump the pump directly to the battery for a second and I can then be on my way again.
I am enclosing some information from a jag forum.
It may help you with giving me directions to my resolving this problem. I have it in the form of a pdf file here, and on my website imertz. Com/downloads/Fuel system check. Pdf
Sunday, October 24th, 2010 AT 10:37 AM