Disco 1 1991 v8 fuel pump electrical wiring

sierrafery said:

Do you have this or hanging inside that compartment?
View attachment 324266

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sierrafery said:

OK, as it's 14CUX you should find the OBD socket somewhere hanging unless it wasnt removed...., i'm not the best with these but i've troubleshooted one few years ago with Hawkeye, on that one the pump was working but not the injectors cos they didnt fire on the diagnostic test and the ECU was at fault... complete your profile with your location maybe someone with hawkeye total is close to you to help cos you can run injector and fuel pump relay tests with it(shown in the attachment), at this point seems that the FP relay and injectors are not getting power and as they are hardwired to the ECU(hence the diagnostic protocol for them)... i dont think both circuits are interrupted and chasig wiring issues while the ECU was not ruled out is feckless... unfortunately without a diag tool you are quite lost...al you can do is to check if the FP relay gets power on the coil with ignition on... the circuit from there to the pump is simple to chrk, remove the FP relay and bridge the contact's cavities with a wire then the pump should run

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sierrafery said:

Are you able to remove the ECU connector's housing as to see which wire colour goes to each pin?... if you can maybe we can do some troubleshooting, if not then unfortunately i can't help more

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sierrafery said:

No worries, i'm not in a hurry with this.... if you can access the plug and the wire colours are matching with the pins like in the attachment we'll speak then,(you said you know te codes but i attach them to be sure, for example NO is brown with orange trace wire and so on)...if not i'm useless so insist on finding somebody with Hawkeye or a diag tool which can work with the 14CUX ECU, provided you find the OBD socket, should be the same https://blackbox-solutions.com/help/SM006.html... ... Good luck

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sierrafery said:

So are you in South Africa? cos then your location on this forum might not help too much to find a hawkeye owner...hence my red signature which i neglected now seing your pain

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classic kev said:

If I have understood what you're saying, you have a spark at the plugs but no fuel at the injectors.

The injectors are on a switched ground, the ECU does this. Check the EFI loom grounds.

The injection pulse is sent to the ECU from the negative side of the coil. If the wire is broken or corroded and the ECU doesn't see the "run signal" from the coil, you'll have no fuel for two reasons, first, if the engine doesn't catch and run on start up, the ecu will kill the pump second, if there is no run signal, the ecu won't switch the injectors. I don't know the D1 very well, all the stuff I did on the 14CUX Hotwire system was on a 3.9 Range Rover Classic but the system is the same. The coil to ECU wire can be traced, you'll have to open the loom but what you need to look for is corrosion but also, do a continuity test I believe the coil signal wire should be a white and black wire on pin 39 (according to the official Range Rover manual for model years 1990 - 1994)

If you mean there is no fuel in the fuel rail, then check fuel pump, fuel pump relay and associated fuse then check fuel pressure regulator.

Looking at the photo showing your ECU, there is evidence of corrosion. Check carefully for corroded wires/plugs and terminals and pay particular attention to ground points, these should periodically be taken apart, cleaned and reassembled.

HTH

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