How much fuel pressure does a stock fuel pump make?

Jimwell150

Active member
I put a electric fuel pump on and have it set at 6psi after driving it for a bit it goes down to 4 psi. I have a holley 350 carb. I was wondering if I put the stock fuel pump back on will it be at 6psi.
 
Some of the fuel pumps put out 6-7#. The aftermarket fuel pumps vary between makes.
The big problem with the mechanical pump is that it hold the pressure for a while to bleed down.
In hot weather this can cause the fuel to boil & flood the engine.
The change in the electric pump loosing pressure is either a defective pump or a partially clogged sock filter on the fuel tank pickup.
 
Jimwell150":2whlv12n said:
The motor is in my rat rod and I'm running a spun aluminum tank.

doesnt matter the type of tank. you can still have debris in the tank causing problems, and that debris could have been pumped in at the gas station. remember that gasoline has a lot of sediment in suspension, and most of the time that sediment doesnt cause problems, but it sometimes does fall out of suspension and clump up large enough to clog fuel filters, and fuel lines, and create havoc with fuel pumps and carburetors.
 
When the pressure goes down, try loosening the gas cap and see if it goes back up. If so it isn't venting and the pump is pulling against a vacuum.
Myway
 
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