Fuel Pressure To Use With Webers

[RSOHC]

I have a 2.7 liter engine with webers, a new stock fuel pump, an in ine regulator and an in line pressure gauge. At what pressure should I set the regulator?

Lauran

[gamin]

I run 3.5 psi with PMO's on a 3.0. Same when I had Webers.

[icarp]

please post of pics of the REGULATOR and pressure gage
2.5-3.0 psi for weber

[proporsche]

manual..PMO

[stownsen914]

Make sure you don't plumb your fuel circuit and pressure regulator as a "dead head" (without a return line). Your comment about "in line" makes it sound like that's what you are planning. That will make your stock fuel pump very unhappy.

[1QuickS]

Porsche tech specification for fuel pressure to Webers is 2.5 m of water which converts to 3.56 psi. 3 to 4 psi is fine.

The PMO "Regulator" does not regulate fuel pressure, it is a flow control valve, period. It has no regulating features. It does regulate fuel pressure by using a needle valve to create an adjustable but fixed restriction in the fuel line back to the tank which then moderates the fuel pressure the pump delivers. Since the PMO device is not self-regulating it will not provide a variable flow rate so as power demands from the engine increase, the fuel flow will not adjust accordingly. This may be OK for smaller engines but large engines will be vulnerable to lean mixtures at high power demands.

[75 911s]

With the "Stock" pierburg CIS fuel pump i was never ever able to get below 4.8 even with the PMO rregulator fully open. I changed it out to a low pressure pump and was able to get 3.5. Just an FYI