fuel pump run permissives Options

[jdlmodelt]

I got my 2.0l 4 cylinder installed. The ignition is functioning. The fuel pump never turns on. I wired it directly and verified that it pumps and builds about 35 pounds. What do I need to look for that would prevent the pump from running under normal operating?
What all wiring connections effect the fuel pump in the engine compartment and under the dash?
Thanks
James

[jdlmodelt]

Its a 76 2.0 l install in a 72 914. The PO ran a pair of wires from the pump to the engine compartment and spliced them to a red and black pair that appear to go to the relay board in the engine compartment

[Dave_Darling]

Verify where the wires go. One should supply power, the other should be grounded full time.

In stock form, the fuel pump is run by one of the relays on the relay board, and draws its power from one of the fuses on the relay board.

Is all of that stuff present and OK?

--DD

[442nd914s]

Maybe between these 2 diagrams, it might shead some light on your situation. Stock wire brown is ground.

[jdlmodelt]

Verify where the wires go. One should supply power, the other should be grounded full time.

In stock form, the fuel pump is run by one of the relays on the relay board, and draws its power from one of the fuses on the relay board.

Is all of that stuff present and OK?

--DD

It all appears to be in order. I'm wondering if the computer is not seeing something that it needs to see? The two center relays are present on the relay board.

[jdlmodelt]

Verify where the wires go. One should supply power, the other should be grounded full time.

In stock form, the fuel pump is run by one of the relays on the relay board, and draws its power from one of the fuses on the relay board.

Is all of that stuff present and OK?

--DD

It all appears to be in order. I'm wondering if the computer is not seeing something that it needs to see? The two center relays are present on the relay board.

This setup has the one fuel line in and one fuel line out and pump has been installed below the fuel tank

[442nd914s]

First verify that the main fuse is working. This feeds all the relays, to include the fuel pump relay. If the fuse is good then continue with the next paragraph.

Try removing the fuel pump relay and check for voltage on socket 30 with the key on. There should be 12v present. If not then there's a board problem. If there is 12v present turn off power place relay back on board, turn key on and check for 12v on pin 13 (harnest near the firewall/this "should" be the original 12v lead to the pump). If 12v is present then you have a bad wire or ground. If 12v IS NOT present, you then have a bad relay. Try placing another relay in its place to verify bad relay. Good luck.
This is based on the diagram I placed eariler.

[sfrenck]

Use the PBanders Fuel Pump Debug flowcharts - very straight forward

PBAnders Fuel Pump Debug

Note: I couldn't get the above website to work off my mobile phone, had to be on my computer (you should see / be able to click arrows at the bottom of the screen to move through the checklist).

[jdlmodelt]

It appears as though the PO wired the pump in wrong. So I'll rewire from the firewall to the relay board. Also, the ground side of the fuel relay coil that goes to the four spade connector is not grounded and so the fuel relay does not engage like it should. When I grounded it and got the relay to engage and got 12v out on the fuel pump terminal the pump still did not turn on ergo pump wired incorrectly. The pump was rewired since it is installed up front like the 76 but installed on the 72.

I could get the engine to start tonight and when holding a fast idle it would hold stable for about 3 seconds and then start to stall and then try to rev up again and then start to stall again. Ideas?