V6 to V8 fuel pressure problem :(

[ChevyTech]

Originally Posted by speedygonzales

Vortec's typically run near 60 PSI. You might want to check into the effects of dialing down that much capability to under 6PSI. Could be an issue with aeration since you will now be sending so much fuel back to the tank. I'm certainly no expert in fuel flow but I think it would be worth while that you look into it.

Also be sure that you get the oil pressure switch into your fuel pump drive circuit. Contrary to comment, my circuit will not have starting issues if the correct oil pressure switch is used, but it is over simplified. Depending on the fuel pump current, and oil pressure switch choices, the pressure switch may NOT be able to handle the current drawn by the FP.

If the current is too much for the oil pressure switch, you simply add another relay. Easy enough to do.

Warning - The advice in the quote above this is bad .

The fuel pressure specification for his 1994 is 9 to 13 PSI.

Vortec was a name give to GM engines that had there new cylinder head design with improved air flow, and has nothing to due with the fuel injection system used or the fuel pressure it runs on.

Your stock pump should be able to do what you want.

I suggest you ignore the suggestion to add and relay to the ground side of the fuel pump circuit. This would require running additional wiring back to the fuel tank or fuel tank ground depending how it is done.

The factory has the fuel pump relay on the power supply side of the fuel pump. Why run twice as many relays so there can be one on the ground side too. I think this would be foolish.