hello intermitent problem here
97 disco with a gems 4l engine

No power at the pump, or the inertia switch. I have the wiring diagram, but it does not look right as there is a big black relay behind the fuse box in the engine compartment, so I am unsure I trust the land rover wiring manual.

It cranks fine, the evap pump works when the fuel pump does not. but the fuel pump does not spin. I started looking at the relays in the rh passenger kick panel, and just by messing with them it started working.

I hate troubleshooting with out a good wiring diagram, but It now works. Any advice would be appreciated, because it will happen again I am sure.

I was reading about the imobilizer failures, and there is a difference on the untrusted wiring diagrams. Does this come into play before or after the inertia switch/

Thanks in advance

fyi fuel pump was changed 40,000 miles ago.

 

Take a probe and check for current during the first 5 second you have the key turned to the start position. If the engine doesn't start the pump will then not continue to run.
A failing crank sensor can also keep the pump from running. You may want to remove the pump and use a jumper wire to start it, if it won't start then, you are out of luck, if it runs, I would look closely at the fuel pump relay or the crank sensor.

 

alot of fuel pumps also default to the engine oil pressure switch, so if the relay fails, the pump will get current when the motor is cranking and builds oil pressure, usually resulting in an extended crank with start. not sure if the gems do this but it may be heplful.

 

Now I am even more confused

I have a copy of the 1997 discovery electrical troubleshooting manual, and I fail to see a crank sensor, oroil pressure switchin the fuel pump circuit.

No codes stored.

Which manual do you find covers the proper configuration of this model, or is that why they get a bad rap for being electrical nightmares.

Thanks for your help

 

This is what i would try. Check for power at pump with key on. Then check for power at pump while cranking. If no power run jumper from b+ to pump. If pump is not working thoroughly check ground, creat one if ness. If its still not working the pump is bad, or headed in that direction. so the oil pressure switch is not wired into the fuel pump circiut at all?

 

PM me with your tele number and I will call you right back.
Mike

 

No power positive at the pump, or the inertia switch, engine cranks. When I first turn the key I can normally hear the pump, but it does not dothe prepumping. Can jump the pump to positive and negative and it works, we are missing the positive, the ground is good.

There are clicking relays under the hood, and in the passenger side kick panel.

Ikeep looking at the land rover electrical troubleshooting guide, and it does not reflect the actual configuration of the vehicle.Any one knowwho makes a wiring manual that reflects actual wiring configuration of the vehicle other than the OEM, orcan expalin which configuration is which in the manual, because it does not appear they placedall the components as installed at thefactory in their manual.

Thanks in advance

 

http://www.green-oval.com/joomla/ind...&Itemid=29

The GEMS is a very simple manegment system, one step above a carb and distribitor.
I would look into the fuel pump relay.

 

Thanks for your help, is the link supposed to go somewhere?

Where is the relay hiding????

 

Yes that link leads to the RAVE download.
RAVE is THEE Rover shop manual.