EFI/fuel pump hell - Help (1 Viewer)

[Chase77]

All- I've read every post on EFI / fuel pump issues but I can't figure this out after weeks of tinkering.

I've replaced the open circuit relay. Tested the EFI relay but still no fix.

Here's what I know/have done:

1. At the connection in the drivers rear wheel well the wires were corroded so I cut them to splice.
2. When I jump the FP and B+ at the diagnostic port in the engine bay there is no voltage getting to the wires in the rear wheel well going to the pump.
3. When I jump the FP and b+ on the open circuit relay(fuel pump relay) in the passenger kick panel, I get a solid 12 V between the green/red wire and the black / white wire in the rear wheel well coming off the wiring harness.
4. This is why I bought a brand new open circuit relay from Napa. I assumed it had to be the OCR bc jumping at that point put voltage back to the rear wheel well connection. Still no voltage when I installed the new relay and then jumped the FP and b+ in the engine bay though.
5. Wiring can't be bad since it gets 12v at the wiring harness in the rear wheel well when I jump it at the open circuit relay.
6. Fuel pump is good bc it runs when I jumped it directly to the battery.

Now what do I do? I'd appreciate any ideas. I have the FSM but no ideas on what else to do.

 

[LAMBCRUSHER]

have you tested the OCR relays coil trigger wires? Perhaps there is a bad connection/ blown fuse/broken wire that feeds voltage to the coil of the OCR. if no coil voltage, then it won't matter if the relay works or not. find the 12 volts and a ground that should power the relay itself and make sure they are getting to the relay...the relay uses power to switch power...clear as mud?

 

[Chase77]

have you tested the OCR relays coil trigger wires? Perhaps there is a bad connection/ blown fuse/broken wire that feeds voltage to the coil of the OCR. if no coil voltage, then it won't matter if the relay works or not. find the 12 volts and a ground that should power the relay itself and make sure they are getting to the relay...the relay uses power to switch power...clear as mud?

I tested the voltage at the OCR relay plug. It's getting 12v there. A that what you mean?

 

[Chase77]

All- I've read every post on EFI / fuel pump issues but I can't figure this out after weeks of tinkering.

I've replaced the open circuit relay. Tested the EFI relay but still no fix.

Here's what I know/have done:

1. At the connection in the drivers rear wheel well the wires were corroded so I cut them to splice.
2. When I jump the FP and B+ at the diagnostic port in the engine bay there is no voltage getting to the wires in the rear wheel well going to the pump.
3. When I jump the FP and b+ on the open circuit relay(fuel pump relay) in the passenger kick panel, I get a solid 12 V between the green/red wire and the black / white wire in the rear wheel well coming off the wiring harness.
4. This is why I bought a brand new open circuit relay from Napa. I assumed it had to be the OCR bc jumping at that point put voltage back to the rear wheel well connection. Still no voltage when I installed the new relay and then jumped the FP and b+ in the engine bay though.
5. Wiring can't be bad since it gets 12v at the wiring harness in the rear wheel well when I jump it at the open circuit relay.
6. Fuel pump is good bc it runs when I jumped it directly to the battery.

Now what do I do? I'd appreciate any ideas. I have the FSM but no ideas on what else to do.

7. When I test the voltage at the b+ terminal on the diagnostic port in the engine bay I get 12v.

 

[LAMBCRUSHER]

a relay needs a complete circuit at its coil to close its contacts. You say you measured 12 volts + at the harness connector to the OCR...where did you pull the ground from?

 

[Chase77]

a relay needs a complete circuit at its coil to close its contacts. You say you measured 12 volts + at the harness connector to the OCR...where did you pull the ground from?

The body was the ground I used? Electrical virgin here. Is that wrong?

 

[LAMBCRUSHER]

not really wrong, but are you certain the relay coil is getting the same ground, or does one of the wires in the harness connector feed ground to the coil? If it gets its ground from a wire, you should make certain that ground wire is continuous to ground, does make make sense? See, if the relay coil isn't getting a good ground, you can feed it +12 all day and see nothing change, savvy?

 

[Chase77]

Bump..... Double checked the EFI Main Relay. There is continuity but I can find ranges of what is acceptable posted. It's showing .02 resistance. Is that normal?

Any other ideas on what could cause 12 v to be getting to the rear well when I jump it at the open circuit b+ and FP but getting zero v when I jump the same ports at the diagnostic box is the engine bay? I know I have to be one step away but can't figure out the next thing to diagnose. Thinking it may be time to get her towed to the shop for the first time in 10 years.