Hi
I have a 71 p1800E with the 3 port fuel pump. It seems to work fine, when I turn the key it pressurizes the line and the car starts fine. After running for more than a half hour or so it starts to buzz while I'm driving (loud enough to hear it at an idle). It comes and goes but I suspect its near death. I've had a number of old VW's that showed the same symptoms.

My question however is the correct plumbing of the 3 port pump. Last year I replaced all the fuel lines and connections and am curious if I messed it up (or maybe it was backwards to begin with?).

I was trolling around the porsche 914 sites as they used the same system and found this description quoted below.
"It is possible for the pump to run while hooked up incorrectly. There are three hose connections. They are "D" (pressure - to engine),
"S" (intake - from fuel tank, large outlet), "R" (return - to fuel tank, small tube). If "S" and "R" are reversed the pump will suck unfiltered fuel and rust or other material can easily contaminate the injectors or even jam the close tolerance pump! "

I looked on my pump and don't see any markings. anyone have a suggestion of what order they should be?

Also I'm starting the search for a replacement pump and will likely go the 2 port route as that's all that seems to be available. Anyone have a nice description of how they went about it?
I see from the porsche and old saab 99 sites many have used a walbro GCL603

I've also seen these part numbers cross referenced.

Walbro GCL603

bosch Part Number: 251-906-091

vw to bosch
GFP 301 = 251 906 091

vw to bosch
gfp 301 = 0 580 463 016


- Still haven't tested the fuel pressure after the regulator. In the process of either building my own or buying one. Anyone have a nice homemade version suggestion?


Cheers,
Gord