Subaru conversion fuel pump voltage issue

[Big Bear]

Hi all,

Hopefully somebody mind help. My Scooby conversion is very slowly getting there after many months and much head scratching. Sadly I get a spare few hours every now and again to get stuck in.

Engine is now in and turns over etc but won't fire.

I'm getting error code 53 (fuel pump/circuit) and having checked voltage at the pump it's getting nothing like the 12 volts it should. I've taken the pump off and tested it and it all seems fine.

The fuel pump relay is doing what it should and I think the main ecu relay is as well.

Any ideas why the voltage is so low? Could be a bad earth? I can't see where the earth wire from the pump goes. Any pointers appreciated so I can check it.
This is the original wire, the positive is from the Scooby ecu on the new loom.

If it helps its RJES conversion kit.

Any assistance apprciated. It's turning into quite a journey and learning curve but we will get there in the end... Just be nice before winter....

Thanks all.

[Oldiebut goodie]

Have you tried testing the voltage to the pump using a different good earth point? Or checking the resistance of the pump earth wire to same different good earth?

[Aidan]

have you got a split charge relay wired in somewhere ?

[Big Bear]

I haven't tried, testing using a different earth. Good idea.

Hi Aiden, no split charge relays as far as I'm aware.

[syncroandy]

You don't say what voltage you have elsewhere.. that matters too ! Presumably you're measuring the voltage at the FP when cranking ? 'Cos you need to crank the engine before the ECU will switch the FP relay. Maybe your battery is knackered ?

[pionte]

Are you using a RJES modified loom or your own ? My loom was prepared by someone else but I think very similar to Richards , I had only 1 live wire coming from the ECU , but before I connected it I just ran 2 test wires to the pump straight from the battery, You could try this ? This should then work . I then connected the 1 x live feed wire from the ECU and connected the earth from the pump to the chassis bolt securing the pump. I'm sure that you already know, but incase you dont, the ECU will turn on the pump for 1 second when the ignition is first switched on, then again when cranking and running.

[Big Bear]

Thanks all. It is an RJES loom. I'll rig up some test wires from the battery and see what happens.

[Big Bear]

Connected the pump negative direct to battery negative and it lives!!!

Next job, make a nice new earth cus sod knows where the originally disappears to, then throttle cable, exhaust... Soon be done now.