P38A Fuel bleeding

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Flossie

Flossie

Well-Known Member
Posts
11,048
Location
Shropshire
2001 diesel.
Should the intank pump on these work without the engine running?
Fuel tank is now completely empty as are the lines and filter. Before I removed the tank I bridged the relay for a flow test and the pump passed that test ok.
I could hear the pump when I did the test but now I can't. Checked the fuse and that's fine and also tried swopping the fuel pump relay but no ticking with the ign on. If the engine does need to be running for the pump to work , how to I get fuel up to the FIP? Bridge the relay again?
 
Flossie said:
2001 diesel.
Should the intank pump on these work without the engine running?
Fuel tank is now completely empty as are the lines and filter. Before I removed the tank I bridged the relay for a flow test and the pump passed that test ok.
I could hear the pump when I did the test but now I can't. Checked the fuse and that's fine and also tried swopping the fuel pump relay but no ticking with the ign on. If the engine does need to be running for the pump to work , how to I get fuel up to the FIP? Bridge the relay again?
Click to expand...
Pump runs on your model when the glow plugs are on or the engine is cranking or the engine is running.
 
Ok...the pump still runs when jumped. Relay doesn't click. Got power in and out of the fuse number 39. Got power at terminal 30 for relay, got ground on terminal 85 for the relay, got no power on terminal 86 which, I think, is needed to trigger the relay and put power to 87. Jumper wire direct from battery to terminal 87- pump runs. In desperation, I'm no electrical God, I tried one of the other yellow relays in the fusebox and non of them click, in further desperation I tried an old relay I found in a box of other stuff and that one clicks but the pump still don't run.
In further further desperation, I've removed the fuse box and gutted it as far as is possible to try and trace my 'no power at terminal 86' issue but it's not possible to gain access to the rear of the relay connections. Fuse box shows no signs of corrosion or burning, very clean actually.
It's the red/pink multi connection under the fusebox which feeds this relay but unfortunately I didn't print off any wiring diagrams from the workshop manual (not rave but as good as by all accounts) and that's on the wife's laptop which won't work right at the moment.
I'm confused as to what wire is supposed to feed terminal 86? If that will power up then everything will be fine surly....?
Bit lost guys..:(.
When I removed the fuel filter just after I got her, it was empty and the engine kept stalling in drive so I suspect this fault was always there.
 
Flossie said:
Ok...the pump still runs when jumped. Relay doesn't click. Got power in and out of the fuse number 39. Got power at terminal 30 for relay, got ground on terminal 85 for the relay, got no power on terminal 86 which, I think, is needed to trigger the relay and put power to 87. Jumper wire direct from battery to terminal 87- pump runs. In desperation, I'm no electrical God, I tried one of the other yellow relays in the fusebox and non of them click, in further desperation I tried an old relay I found in a box of other stuff and that one clicks but the pump still don't run.
In further further desperation, I've removed the fuse box and gutted it as far as is possible to try and trace my 'no power at terminal 86' issue but it's not possible to gain access to the rear of the relay connections. Fuse box shows no signs of corrosion or burning, very clean actually.
It's the red/pink multi connection under the fusebox which feeds this relay but unfortunately I didn't print off any wiring diagrams from the workshop manual (not rave but as good as by all accounts) and that's on the wife's laptop which won't work right at the moment.
I'm confused as to what wire is supposed to feed terminal 86? If that will power up then everything will be fine surly....?
Bit lost guys..:(.
When I removed the fuel filter just after I got her, it was empty and the engine kept stalling in drive so I suspect this fault was always there.
Click to expand...
There are 3 diodes involved in the operation of the fuel pump relay. I have not got access to RAVE at the moment so I cannot look up the diagrams. Can you not download it onto your computer?
 
Never had any luck downloading rave but I'm useless with pooter stuff. Someone on here sent me a link to a workshop manual which seemed pretty comprehensive, 1400 pages iirc, I only printed off what I thought would be needed for now 3 or 5 hundred pages or so, just diesel no V8, and no wiring diagrams unfortunately. We only have the wife's troublesome laptop and our smart phones.
 
Datatek said:
Pump runs on your model when the glow plugs are on or the engine is cranking or the engine is running.
Click to expand...
Oh..well.... this could be embarrassing for me:oops:.
It's looking possible that I haven't got a fault then, no cranking no running and I 'think' I left the ign on while (cough:rolleyes:)fault finding. I'm clinging on to the thought that once I put the fusebox back together and turn on the ign the pump will run. Glow plugs had probably timed out so no pumpy pumpy:p.
Did notice that the abs relay got quite hot is that normal? No burning or smells though.
 
Flossie said:
Oh..well.... this could be embarrassing for me:oops:.
It's looking possible that I haven't got a fault then, no cranking no running and I 'think' I left the ign on while (cough:rolleyes:)fault finding. I'm clinging on to the thought that once I put the fusebox back together and turn on the ign the pump will run. Glow plugs had probably timed out so no pumpy pumpy:p.
Did notice that the abs relay got quite hot is that normal? No burning or smells though.
Click to expand...
NO relays should get hot.
Relay 12 is the fuel pump relay operated via diodes D2, D3 or D4. D4 is fed from the starter relay R16, I can never remember which of the other 2 are which, but one is fed by a signal from the ECU when the engine is running, the other is fed from the glow plug circuit. The fuel pump is fed from fuse F39 via relay 12, the output of relay 12 is on connector C0570 a White/Orange wire.
 
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