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R34 Gtr Fuel Pump Electronics

sinistaGTR

By sinistaGTR,
in General Maintenance

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sinistaGTR Grand Master

sinistaGTR

Posted
Posted (edited)

Guys I wired in a new fuel pump into my 34 GTR and found it didnt work(and yes I got the wires correct and yes the pump works when tested elsewhere).

After that I resoldered the original fuel pump back in to check if it was a resistance thing etc, but that didnt work either, there is no voltage from the wires at the fuel pump

.

So for the moment I have just added a new relay in and got the power from the ignition circuit to switch the relay on and have the fuel pump direct battery voltage feed.

But I would really like to get the orignal circuit working. The fuel pump fuse is fine. I have checked all the fuses in the boot, near the drivers kick panel and under the near the jump start point in the engine bay. Are there any other fuses or can someone tell me where the fuel pump relay is actually located.

My understanding so far is that the ECU fuel pump relay signal puts out .6v (checked against another ecu in my car), from there I think it goes to an earth controller of some sort and then switches the relay on.

Im just shy of tracing wires, but if anyone can give me a heads up on how the circuit works i would be rather greatful.

Edited by sinistaGTR
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sinistaGTR Grand Master

sinistaGTR

Posted
  • Author
Posted

well.... the fuel pump relay control on the ecu is actually contolled by the inputs the computer receives.

There is a fuel pump drive controller that turns the relay on and off.

Whan i turn the key on i get .6v for 3 secs so this indicates that the the signal is working fine (manual says approx .8v). Seems i may be having trouble with this drive pump controller.

Anyone know where this drive pump controller or the fuel pump relay is located.....im getting closer to this problem

sinistaGTR Grand Master

sinistaGTR

Posted
  • Author
Posted

Ok so quick update.... I took the battery terminals literally off then back on....and BAM 12v out the original fuel pump wires....so now have the 14v direct feed relay with the original fuel pump wiring being the swith for my relay....

random electronics lol

  • 1 year later...
GTR-34A Mentor

GTR-34A

Posted
Posted

bringing up an old thread, went to start the car this morning and it cranked fine but wouldnt kick in...

after abit of investifating we believe its probably the fuel pump as i was not getting any sound prior to cranking (power not getting to the pump??)

checked kick panel, front and rear fuse boxes, all looked good. tried unconnecting the battery and restarting with no luck..

i have a haltech platnium pro plug in that and i will take the laptop down tomorrow and try and see if anything pops up on the logging, and maybe rebooting the ecu (not sure if disconnecting the battery would do this anyways?)...

anyone have any ideas or tips, advice to solve the issues that seem very similar to the above.

any help will be greatly apppreciated.

Cheers,

Anthony

GTR-34A Mentor

GTR-34A

Posted
Posted

Relays are under the rear rt tail light. Make sure you are getting a pulse on that relay and there is 12v on it.

thanks for the tip mate, was wondering where they are.

im pretty hopeless when it comes to fixing things but will give that a shot tomorrow.

just under the internal boot side wall carpet? or further?

GTR-34A Mentor

GTR-34A

Posted
Posted

Relays are under the rear rt tail light. Make sure you are getting a pulse on that relay and there is 12v on it.

Hey mate,

Anything else i should check after doing the above test? what should i check if it is? or if its not etc?

thanks

GTR-34A Mentor

GTR-34A

Posted
Posted

u need to test the power at the fuel pump not the relay. and remember u need to test it while either cranking or wiyhing the first 3seconds or so while its supposed ti be priming once key on

Thanks mate, i will look into doing this on the weekend and go from there.

Cheers,

GTR-34A Mentor

GTR-34A

Posted
Posted

had another look at my issue this morning, and it appears that im not getting power to the relay or the fuel pump.

has anyone had these issues before? from research and looking at wiring diagrams etc it appears the fuel pump control module could be broken. may have to look at hard wiring the pump direct to the battery to fix this? does anyone know an easy way to test if that is 100% the problem, or would be the fact that the pump isnt getting power proof?

here is the wiring diagram i found for reference.

post-85191-0-58317400-1371967241_thumb.jpg

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