electric fuel pump

[k9ulan]

I just installed an electric fuel pump from raff corvair. Now car stumbles on acceleration and sometimes wont idle worth a crap. Pump I pumping fuel to the carbs ok. Anyone else ever had this issue? Runs fine with leaky mechanical pump back on.

[Jerry Whitt]

Testing of the fuel pressure and volume are appropriate.

Pressure at the carburetor inlet should be 3-4 lbs.

[66vairguy]

Some common electric fuel pump issues:

Location -- close to the fuel tank and LOW so it stays primed.

Debris --- Fuel filter MUST be installed between tank and BEFORE electric fuel pump.

Fuel pressure ---- A COMMON mistake by some vendors is to select the WRONG fuel pressure rating. Example - Pump rating is 5 - 8 PSI so it's assumed the pump puts out 5PSI. In fact the pump puts out 8PSI!!! Always ignore the lower pressure value and go by the highest value. The low value is ONLY for maximum flow, something that never happens on most cars.
The Corvair wants to see 4-5PSI, EXCEPT Turbo charged cars which require a precision fuel pressure regulator to keep the pressure between 2-3PSI at sea level, 1.5 - 2.5PSI at 5,000 ft.

Pumps ----- Over the years two fuel pumps have been reported to be very reliable, others not so much.
Good pumps: Airtex # E8016S @ 2.5 - 4.5PSI (4.5PSI at Corvair flow rate). Facet #40105 @ 3 - 4.5PSI (4.5PSI at Corvair flow rate).

I would suggest determining what fuel pump you have and if all else fails, check the fuel pressure. BTW if the pump is mounted near the engine (not good) it may be pulling in air at the hose fittings BEFORE the pump.