Porsche Repair: 72-914, fuel pump, penpals


Question
Dave,I received my e-mail conformation from all experts. Sorry I addressed it to Ben ? I guess that I had too many kids in my last class yesterday. Hope you can help us on the fuel injected 914. Thanks again, Gary

Answer
Gary...Hi.  We here at allexperts get quite concerned when we think our penpals are two-timing us.  Ben better not be trying to lure you away from me.  Yuck, yuck.

So while I was dreaming about your problem last night I had an idea.  I don't have time to test this theory today, but wanted to pass it on 'cause I know you're anxious to get this resolved.

This is an attempt to explain why your two fuel pump wires might be 'grounded' and that might be OK.

Maybe... since the pump is wired through a relay, the wire (black-red) that should receive 12v when the relay is energized just sits there acting like a grounded wire when the relay isn't active.  It's perfectly resaonable to NOT see 12v at the pump when the relay is inactive, so maybe during this time the wiring in the relay is such that the relay end of the black/red wire is grounded...until the relay is energized and switched to 12v, then the wire goes to 12v and activates the pump.  This makes sense, all I have to do is test it.

In the meantime, you could test it too...and if I were you I'd be quite suspicious about that relay being faulty.

Please write back next time with what you find out.  Thanks.

Dave