Carb swap wiring help.

[CJ Tanner]

Hey guys I’m new here and looking for a little help on carb swapping my pickup. It’s. Vortec 355 with a nv3500 5 speed. Fuel pressure regulator is installed but I’m needing some help on getting the fuel pump to kick on. Thanks guys.

 

[7thdarkangel]

Rewire your relay like this.

You must be registered for see images attach

 

[Bigred1990]

Rewire your relay like this.

You must be registered for see images attach

This is such a vague diagram lol. Where is the grey wire coming from that connects to the tan and other Grey? I’ve hooked mine up similar to this diagram and everytime I go to connect the battery it runs the pump instead of it running every time the ignition is turned on.

 

[7thdarkangel]

the only thing your doing is modifying the relay wiring. nothing else. the green wire should trigger the on/off of the relay. This should be connected to a continuous ignition source. some circuits will turn off when starting. pick one that doesn't. The orange wire is your live wire that gets turned on/off by the green wire. black gets grounded up near the relay (needed for relay to work). IIFC the red wire was to the computer which is no longer needed. cut it and cap it.

If that doesn't help, spent 10 min with a tester and a few jumpers and see what triggers what and wire accordingly. basic two wire electrical work.

 

[DemonDuallie]

If you cut 1 wire form the 4 wire plug at the old distributor, hook it to tach signal on hei distributor, it will give you your power for the fuel pump. I actually took the intank pump out of the system. It's still in the tank, I worked my new inline pump into the relay circuit by cutting the wire coming from the fuse to the pump. I left the intake pump, so if I ever run out of gas, I can use it as a lift pump. The little pump pulses when key turned on then once engine starts, it runs constant.
I was having regulator issues, went through 3, then just decided to go with inline pump. Was pushing the full pressure through the regulator. Wouldn't adjust down.
Good luck! My 454 works way better carbed than ever did tbi