Hey yall, I'm having an issue right now with my fuel system. A while back I swap the engine in my 88 Firebird (used to be a 305 TBI) with a carbed 357. Fast forward to now, I have a Holley 650 Street Warrior on the car now. My issue is I was wanting to use my original in tank fuel pump with the carb. I already bought and installed a fuel pressure regulator and gauge from the feed line up in front in the engine bay. My problem is that when I click the key to about to the start the car, I hear the pump prime like normal and the gauge jumps to the like 7 psi. Okay, great. I have a clear inline fuel filter up near the carb so I see the fuel fill the filter partially. Once I start the car, the pressure starts dropping until the car dies out. I wait, turn the key, hear the pump prime, psi up to the 7ish again and she starts again and this is just a cycle. So I dont know what to do anymore. Might just go back to the traditional mechanical fuel pump but instead use a holley or edelbrock mechanical pump.

 

Sounds like maybe your pump in losing power after you release key back to run position possibly? Had a friend experience this situation 20 some years ago. Dropped tank replaced pump only to find the problem was in the ignition switch.

 

When you hit the key, your ECM runs a runs the fuel pump. Any time you cycle the key, you will hear it run for a few seconds. The ECM doesn't continue to run the fuel pump, because it doesn't know the car has started and is running. In order to get the pump to run, while the engine is running, you need to supply power to the fuel pump relay. The way I did it was run a "hot on acc" wire to the relay. The downside is that any time your key is on, the fuel pump is running and can lead to a premature death because it can run unnecessarily . Also, make sure you have the 3-way style regulator, so any excess fuel is returned to the tank.

 

I don't know, which is why I am asking, but wouldn't his car have the oil pressure switch tied into the fuel pump circuit?
Without oil pressure sensed, it would cut the fuel pump off. Or does this not apply here?

 

The ECM would need to see the ignition pulses to keep the pump running. I really haven't been able to sit and figure out what the purpose of the oil pressure switch does in the FP circuit. Just power the FP relay with a source that is hot with the key on, and it'll run. As mentioned above, try to not let the car sit with the key on and not running. Maybe a kill switch on the ground side of the circuit to the FP relay to shut the pump off in case of a problem, or for the times needed to turn the pump off with the key on.

 

And by all means get rid of the glass filter on the pressure side of the pump to the carb!!!

If the glass should break the car will burn to the ground.