OK this is very very strange, please hear me out. My disco has had a random starting problem where it will not start and I have replaced the fuel filter and the fuel pump relay I thought everything was cool but it just started doing it again. Here is were it gets strange I was trying to check to see that the fuel pump was working. When I open the back door it starts! then I shut the back door and it wont! Open it again and it starts! Any ideas would be great!
Thanks!

 

The fuel pump will only run for just under 5 seconds when you turn the key. If the engine isn't actually running the fuel pump won't run.

 

OK my theory has been tested all night! No joke it will not start unless i open the rear door! And then when I shut it it might start fine for a few more tries.

 

Check ground wires.

 

Can someone please direct me to the location of the ground wires?