newbie here and hi to all. Have a 96 disco, gas, SE7. 160k. Have a
fuel pressure problem. Sometimes it starts and sometimes not. It's been setting for a few months now as I've been finding time to go thru the system. Have changed out both relays, fuses and starting to run thru the wires. The problem is the run relay in the master/main is not being told to turn on. If i hold the relay in the car starts and runs, sometimes it will restart a few times before it goes back to not getting the run relay. I've used the test light to ground out the computer and i can see/hear the relay kick on. The question is what inputs turn on the output for the relay?
Is there a fuel pressure sensor that could be telling the computer that it's at high pressure? Is the engine sensor on the harmonic balancer bad telling the cp the motor is not turning? HELP!

 

I think if it runs well while your're holding the relay in (driveable?), you're down to the ign. sw. signal or the inertia switch (under hood, pass side on firewall, black reset button)

You said you've changed/checked fuses and relays

The fuel press regulator is vacuum operated, with key-on you should have well over 35psi at fuel rail.


luck,greg

 

thanks, I'll start chasing down the ign. sw. signal.
The inertia switch is good, that was the first thing i checked when the trouble started.
thanks for the fuel pressure being vacuum. that takes it out of the mix.