928 GTS fuel relay problem

The easiest way to get at the CPS is to remove the air filter box, upper and lower, remove the MAF, remove the rear fuel damper and fuel regulator assembly then you should see the connector for the CPS as it connector is on the bracket for the throttle cable.

Yes....its that buried.

If I'm not mistaken, on your model 928, then both your ignition and fuel delivery would be shut down by a faulty CPS sensor. Byoassing the fuel pump relay would not run the car.

Thanks everyone, I have looked at a lot of things. My problem is that I can find no connecting wire between the ignition switch and fuse 39 on bus 15. There must be some indirect way that 12V+ power is reaching fuse 39.

Did you merely substitute relays for the fuel pump relay? I recommend that you jumper the fuel pump relay between terminals 30 and 87. This removes the relay circuit form the equation.

My thoughts are that if the car runs with the jumper in place, your LH is indeed on it's way out. The fuel pump relay gets it's ground from within the LH. I have had 2 different cars with this issue. Both cars ran fine with a switchable jumper in place.

If the car does not run with a fuel pump jumper, then it is most likely the Crank Positon sensor. When the CPS is going bad, the car can do all kinds of crazy things and have innumerous weird symptons.

Bad ignition switch (where you put you key in to start the car) also makes VERY STRANGE things happen to our cars and is relatively easy to fix. The strangeness is usually weird electrical stuff that is intermittent and not usually related to how the car runs or drives.

I am thinking this sounds reasonable.