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2006 evo 9 fuel issue, where to wire fuel trigger?


Robsevo9

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Hello, I am having a fuel issue with my evo where the white oem power wire isn’t getting any power to start the fuel pump. I am just going to use the g4x to trigger the relay. Aux 10 and 11 are already being used idk on what previous owner hacked all these wires and I do not want to touch anything. Does anyone know how and where can I connect a wire to trigger the relay for the fuel pump?

1E9DFA24-190D-4255-B8DF-B4A07DABB22F.png

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4 hours ago, Adamw said:

Only Aux 9 & 10 on the expansion ports can be used as outputs.  

Can you not use the existing fuel pump control wires - Ign 3 or Aux 12?

Thanks for the reply, on the ecu harness I am getting power for that wire that goes into the g4x, a direct wire from the ignition might work but I would need to relay and fuse it. I am trying to keep it oem and not hardwire anything. I’m going to look at aux9 to see if it’s taken up thanks

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Note the ECU only outputs a ground signal that goes to the fuel pump relay, it does not supply power to anything.  It sounds like you are expecting something different?

I have stitched together a few pages from the factory wiring diagram to show how the stock FP circuit works in the pic below (click on it for a bigger version). 

12V comes from the battery at top right to FPump relay 1, this relay turns on with the ign switch - it is not controlled by the ecu.  When ign is on 12V will come out of FP relay 1, pin 1 and supplies 12V to pin 4 on FPump relay 2, when the ECU grounds the Ign 3 pin this relay closes and the fuel pump will run.  FPump relay 3 just controls whether the power from relay 2 goes straight to the fuel pump for high speed mode (green route) or through the fuel pump resistor for low speed mode (purple route).   

77XcLSg.png

 

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13 hours ago, Adamw said:

Note the ECU only outputs a ground signal that goes to the fuel pump relay, it does not supply power to anything.  It sounds like you are expecting something different?

I have stitched together a few pages from the factory wiring diagram to show how the stock FP circuit works in the pic below (click on it for a bigger version). 

12V comes from the battery at top right to FPump relay 1, this relay turns on with the ign switch - it is not controlled by the ecu.  When ign is on 12V will come out of FP relay 1, pin 1 and supplies 12V to pin 4 on FPump relay 2, when the ECU grounds the Ign 3 pin this relay closes and the fuel pump will run.  FPump relay 3 just controls whether the power from relay 2 goes straight to the fuel pump for high speed mode (green route) or through the fuel pump resistor for low speed mode (purple route).   

77XcLSg.png

 

Thank you so much! I found out that I do have power at the ignition wire (black and white)#2 but somewhere in the middle it gets lost and my relay isn’t getting that power on #3 for my first relay… and same for the 2nd relay but it has very lil light and my tester is very dim….. here’s the crazy part. The both click when I turn the key to On pos, so somewhere from the ignition to relay 1 pin 3 there’s a short….Previous owner hacked a lot of wires in the car. I was thinking of using pin 21/ing3 as a trigger to my double pumps. Which is the oem output for fuel pump

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