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1970-1995 Range Rover Classic
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Discussion Starter #1
We have a P38 here that came for an engine swap.
Done that, non starter.
tried everything, no noise from the fuel pump.
took it out, was botched up, ordered a new, original VDO.
Got it within a week, great, put it in NOTHING.
I know positively there WAS power at the WU feed to the pump. Now there isn't.
what is weird is when I plugged it in the hazard warning started to work.
BECM is not in alarm state says Hawkeye.
My Rovercom is not talking to me right now otherwise I'd try that.
Alarm figure in the Engine ECU is the same as in the BECM.. well one says 0763 the other one say 00763 I suppose that IS the same.
WHAT could it be, I am @wit's end.
 

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1995-2002 Range Rover P38A
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Re: Changed fuel pump, no power to inertia switch... despera

Model, engine type and year?
Sounds immobilised/ lost synch but there are different procedures for synching depending on GEMS/ Bosch or Diesel.
 

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1970-1995 Range Rover Classic
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455 Posts
Discussion Starter #3
Re: Changed fuel pump, no power to inertia switch... despera

thank you Bean.
Diesel it is, 1997.
We checked the earth on the relay block under the bonnet, cleaned it just in case.
no juice on the WO cable coming from the relay.
 

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1995-2002 Range Rover P38A
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Re: Changed fuel pump, no power to inertia switch... despera

So do you have power through fuse F39 and then to pin 3 on RL12?
 

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1995-2002 Range Rover P38A
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Re: Changed fuel pump, no power to inertia switch... despera

and was this the earth that you cleaned?
FPRearth.JPG
 

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Re: Changed fuel pump, no power to inertia switch... despera

If your hazards come on when the fuel pump was connected it indicates the inertia switch is triggered, as this is what should happen if it is triggered (as in a crash), the pump provided the ground path for the BeCM monitoring pin.

If your a pro outfit you should be able to read and follow the RAVE ETM.
 

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1995-2002 Range Rover P38A
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Re: Changed fuel pump, no power to inertia switch... despera

If your hazards come on when the fuel pump was connected it indicates the inertia switch is triggered, as this is what should happen if it is triggered (as in a crash), the pump provided the ground path for the BeCM monitoring pin.
If your a pro outfit you should be able to read and follow the RAVE ETM.
I hadn't got that far down the line- was running through in baby steps :)
The OP did say no power at WO line which is feed into inertia switch. Out of interest, when inertia switch is opened (connected to pin 2 C114 BECM) does that then take out power to F39? Just curious...
Good spot on the hazards though.
 

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1970-1995 Range Rover Classic
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455 Posts
Discussion Starter #9
Re: Changed fuel pump, no power to inertia switch... despera

LarryS I am a pro but not with hacking computers.
I have never managed to get the rave to run in my life. They are scrambled pdfs and I haven't got the enigma machine to decode them.
yes I have the electronic circuit manual here, in Spanish :) or in french..

Orange bean, thank you that is very kind of you.
it is yes and yes. Yes got power, yes I have cleaned that earth and yes I have swapped the relay against another one.

BTW maual diesel p38s are very rare here so I am not in the habit
 

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1995-2002 Range Rover P38A
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Re: Changed fuel pump, no power to inertia switch... despera

So, have you checked/ reset the inertia switch?
You have power to pin 3 of relay but not pin 5?
If you jumper the relay pin 3 to 5 does the fuel pump run?
 

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1970-1995 Range Rover Classic
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Discussion Starter #11
Re: Changed fuel pump, no power to inertia switch... despera

Thank you.
I just went to check again, because it wasn't me who had measured, I had been at the inertia switch.
Sorry there is only 1.7V at pin 3, pin 1 has 12V as it should.
I will jumper 1 to 3 and report back, then 3 and 5.
 

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1995-2002 Range Rover P38A
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Re: Changed fuel pump, no power to inertia switch... despera

DONT jumper 1 to 3. You'd be bridging 2 circuits. Blue smoke may be released!
1 step at a time...
3 to 5
 

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Re: Changed fuel pump, no power to inertia switch... despera

If you only have 1.7v at pin 3 do you only have 1.7 volts at fuse 39 (relay unplugged)?!
 

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Re: Changed fuel pump, no power to inertia switch... despera

So therefore, with relay unplugged you have 12v at pin3 relay socket, but with relay plugged in you don't?
 

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1970-1995 Range Rover Classic
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Discussion Starter #16
Re: Changed fuel pump, no power to inertia switch... despera

Thanks a lot there is 12v at the fuse, ignition on or off
What i don't understand is there is no 12v at the brown and black wire on the red c575, excuse my ignorance but according to my diagram that feeds everything
 

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1995-2002 Range Rover P38A
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Re: Changed fuel pump, no power to inertia switch... despera

Thanks a lot there is 12v at the fuse, ignition on or off
What i don't understand is there is no 12v at the brown and black wire on the red c575, excuse my ignorance but according to my diagram that feeds everything
That looks like an output from the glow plug timer unit so prob only powered when timer active. That's to the coil side of RL12 though. You're testing the switched power feed side.
You're saying you have 12v at fuse out, 12v at RL12 connector 3 relay out, but with relay in, that drops to 1 volts or so.
You need to get 12v at pin 3 of RL12. If you can't, problem lies in your fuse box.
Using a fused jump cable, inject 12v into pin 1 of C177.
Check for 12v at pin 1 WO C111 inertia switch if yes
check for 12v at pin 3 WU C111 if yes
check for 12v at pin 4 WU C110 at pump
Pump should run. If not, problem is with pump or pump ground.
Good luck hunting. Sleep time here in UK.
 

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1995-2002 Range Rover P38A
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Re: Changed fuel pump, no power to inertia switch... despera

Alarm figure in the Engine ECU is the same as in the BECM.. well one says 0763 the other one say 00763 I suppose that IS the same.
The EMS code? No, should match exactly. Try writing 0763 to the BECM if it is a diesel.
 

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1970-1995 Range Rover Classic
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Discussion Starter #20
Re: Changed fuel pump, no power to inertia switch... despera

Many thanks to Mr Bean for all his help.
YES, it was the blooming fuse box. So I have bypassed the connection in the fuse box externally and it runs and we managed to start the car after 6 months.

Unfortunately this is Costa Rica and the idiot who 'repaired' it before me has lost the linkage for the accelerator potentiometer, ANR3308 ss by ANR5703 .
LR calls it 'obsolete', this is probably what the other 'mechanic' thought.
I have already written to everybody I know in Britain but no luck.
 
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