No Fuel Pressure (power to pump, pump tested, have spark)...)

[Macro1]

1999 Discovery 1.

Had a different truck earlier this year with a problem with no power to the fuel pump, but now I've got another vehicle with different symptoms.

Heres the skinny:

Truck died outside of the gas station. Will crank over but does not turn over.

- No Fuel Pressure
- Has Spark
- Removed fuel pump and tested from battery- works great. However, it does not seem to be working and does not make a sound when installed inside the tank.
- Has power to the fuel pump. However, for testing purposes, i had to temporarily bypass the emergency shutoff relay thing( sorry I don't remember, but its the last plug prior to the wiring harness). I did so because I would loose power after its plugged in. I DID TEST WITH A FUNCTIONAL one from a working Rover but it does not change the fact no power coming from the relay "thing".
- Replaced Crankshaft positioning sensor AFTER the truck broke down due to a previous issue with codes.
- Currently has codes: P1193, P1317, P0340, P1317 (again) These codes where present prior to there being no fuel pressure.
​

Any ideas? Where should I check next? I have spent more time reading DWeb trying to figure this out then working on the truck and I'm having trouble knowing which direction to go from here.

Thanks!!!

 

[flyfisher11]

Are you sure the pump isn't dying? Do you have access to a good known pump? My '95 RRC's fuel pump died a slow miserable death and caused me a lot of useless trouble shooting.

 

[Macro1]

Are you sure the pump isn't dying? Do you have access to a good known pump? My '95 RRC's fuel pump died a slow miserable death and caused me a lot of useless trouble shooting.

When I removed it from the tank and connected it a battery it seemed to pump pretty hard.

I do not have another pump to compare it to as the other two rovers are non-evap.

I think if it was slowly dying it would "Attempt" to make some kind of sound. But I think the bigger issue is there is no power going to the pump when the emergency shutoff is plugged in (even when a shutoff is connected from a functional rover).

 

[desertdude]

I had a similar bugger less than a weak back, no power to going to the new-ish less than a year old fuel pump. The car just died while in motion ! Had spark and fuel or so I thought.

Turned out to the be the fuel pump relay in the passenger footwell, the metal capped one, there should be two if either is buggered the truck wont start. Still don't fo sure if it was either the fuel pump one or the ECU one. But messing about with both seem to work ( Swapping them, then changing them with the spare I had etc etc )

You do mention a "relay thing" in you post but hard to make out to excatly what you are refering too

 

[DMac25]

Considering that it worked on the bench and not in the truck, possible that you have grounding issue to the pump or the pump is going bad. It is possible when the pump is activated in the truck that it draws too much current and opens the relay contacts.

Verify a good ground (volt drop the ground side) then put an ammeter in line with power side and check for draw. If you can't get power back there then you will have to check at the relay.

 

[Macro1]

The car just died while in motion ! Had spark and fuel or so I thought.

Looks like yours has similair symptoms.

Turned out to the be the fuel pump relay in the passenger footwell, the metal capped one, there should be two if either is buggered the truck wont start. Still don't fo sure if it was either the fuel pump one or the ECU one. But messing about with both seem to work ( Swapping them, then changing them with the spare I had etc

Is there another fuel pump relay other than the mount function relay under the hood? I see you have a 1998, and I thought 1996-1999 D1's had the multifunction relay for the fuel pump and ECU.

 

[MUSKYMAN]

the issue I have seen over and over with these is that the spade connectors in the plug get bent and dont make good enough contact.

unplug the plug at the tank and you will see a little yellow cap on the plug. remove that with a small pick and then use the pick to bend the terminals a bit so there is more pressure on the spade connector once it is plugged back in.

this has fixed a number of trucks now for me

 

[Macro1]

unplug the plug at the tank and you will see a little yellow cap on the plug. remove that with a small pick and then use the pick to bend the terminals a bit so there is more pressure on the spade connector once it is plugged back in.

Just pried back all the terminals to make sure they have a good connection and no difference.

 

[ptschram]

Provide the pump with an independent power source, see if it runs then.

Non-AEL pumps can be used in AEL trucks, you will have an eternal CEL, but they work, similarly, if you cut the tab off the top of the pump, an AEL pump can be used in a non-AEL fuel tank.

If it's the connector as Thom suggested, I have the harness that runs from the left wheelwell to the pump, but they are kinda expensive.

P/N for the pump is WFX 101200, IIRC, new they run about $350-375 depending upon exchange rate-Delphi brand.

 

[ptschram]

I had a similar bugger less than a weak back, no power to going to the new-ish less than a year old fuel pump. The car just died while in motion ! Had spark and fuel or so I thought.

Turned out to the be the fuel pump relay in the passenger footwell, the metal capped one, there should be two if either is buggered the truck wont start. Still don't fo sure if it was either the fuel pump one or the ECU one. But messing about with both seem to work ( Swapping them, then changing them with the spare I had etc etc )

You do mention a "relay thing" in you post but hard to make out to excatly what you are refering too

This only applies to pre-'94 Lucas Discos. Yours is an oddity to most of us in North America!

 

[pdxrovermech]

push down on top of the inertia switch, oh sorry, "the relay thing".

but no really, sounds like a connection issue. the wire might get voltage, but wont carru the load because of a broken wire.

 

[ptschram]

push down on top of the inertia switch, oh sorry, "the relay thing".

but no really, sounds like a connection issue. the wire might get voltage, but wont carry the load because of a broken wire.

My '93 LWB had a similar issue. When you had the pump disconnected, plenty of power. Hook up the pump, voltage fell to zero. In my case, it was the pump drawing too much current, but not enough to blow the fuse.

Independently powering the pump removes the truck from the equation and allows us to determine if it's the pump or the truck.

 

[Macro1]

GOT IT FIGURED OUT!!!

push down on top of the inertia switch, oh sorry, "the relay thing".

LOL! Thanks for the tip. A simple press on the inertia switch did the trick. (man I feel silly).

Independently powering the pump removes the truck from the equation and allows us to determine if it's the pump or the truck.

Removed pump and tested using a separate battery. Worked fine. even though I am getting power to the pump (tested by using a tester light) I decided to see if there is enough current going to the pump.

I first tested the white/purple wire from behind the column inside the cab. Pump worked great.

I then tested from the plug underneath the drivers rear wheel arch. Pump failed to work even though my tester light indicated there was power.​

Bottom line is even though there is power going to the pump, there isn't enough current. So looks like all I need to do is run a new wire to the pump!

Thanks guys for your help. atriot:


PS. What would cause a wire (most likely inside the cab) to loose current in the middle of driving?


EDIT: Ran a new wire to the pump and started right up!