Porsche Repair: 928s4 fuel pump, rubber line, excess fuel

Question
Hi Dave
My 928s4 1989 lost all power then cut out and will not start but is still turning over I think its the fuel pump put not sure how to test the pump is still working, I've looked at the fuse and relay and they are ok.
Thanks
Mark

Answer
Hi Mark,

Here's the fuel pump test:

1.  Gather: rags, container to catch fuel, helper
2.  Depressure fuel system by removing gas cap.
3.  Locate the fuel connection in the engine compartment...there's a hard line (actually three, one for fuel in, one for excess fuel returning to the tank and one for a vent) leading from the fuel tank to the engine compartment...before it reaches the intake manifold there will be a flexible rubber line...at that point there will be a connection you can use for your test.  Undo the connection.
4.  As you prepare to catch the gushing fuel (about 15psi) your helper will crank the engine a couple times.  A gush is good, a trickle is bad.  

You also have a suspect fuel filter.  It's hidden under the car in that hard line I referred to not far from the fuel pump itself, not far from the tank.  While the system is depressurized you could change the filter.  Remember here though that even if it's depressurized, gravity will push the fuel tank gasoline right into your face while you fumble with the hoses.  Sounds like fun right?

Let me know if you need anything else.

Dave