Bosch Fuel Pump for 1973 914 2.0L, Part numbers required Options

[sburns1967]

Restoring a 1973 Porsche 914/4 2.0L using D-Jet.

Arrived with the engine out so I have never seen how the fuel delivery was connected.

Pump has a relocate kit to the front steering rack area.

From what i can find the official pump for this configuration should be:

Bosch 0 580 463 005 (Porsche: 311 906 091 D) - 3 port pump

I have the:

Bosch 0 580 463 016 (Porsche: 043 906 091 or 923 094 906 35) - 2 port pump

I assume the 3rd port on the original (005) pump is the injector return line.

Seeing that the 005 is very rare these days can I use the 016?

The pressures and volume seem slightly different but not sure enough to matter with regulation down to I believe 2.0 bar?

If I do use the 016 pump do I just plumb the FI return line directly back to the return fitting on the fuel tank when using the 2 port (016) pump?

Does not routing the return through the pump mess with fuel pressures at all?

[emerygt350]

Don't bother with the old 3 port. Just make sure you have stainless lines with the pump in the front. Return can just go right to the tank.

[wonkipop]

Does not routing the return through the pump mess with fuel pressures at all?

no it does not mess with f pressure.

the injection circuit return line in the 3 port set up does not send fuel through the pump.
the third port was to pressure relieve the pump itself (and the injector circuit up to the fpr if the fpr failed and jammed closed). the t- junction was for the pressure relieved fuel from pump to make its way back to the tank. thats all. to some extent it was also a route for air bubbles to be released out of the pressure circuit and fuel pump head.

modern two port pumps pressure relieve back through the fuel supply port via the supply line from the tank. although when i say modern a lot of merc fuel pumps from that era (late 60s and early 70s) were already using the two port version of the bosch pump. the 3 ports might have been just for the D jet and mech injection cars had a two port, not 100% on that, but do know that some were two port back then.