Porsche Repair: porsche 944, porsche 944, loose connections

Question
My 1983 944 has a strange fault.
It starts immediately but only runs for about 5 seconds. However if you hold the key in the start position keeping the starter motor running it will run but very rough  (also not good for the starter motor have had to replace it) Then when you take a plug out it is covered in carbon as if it is running very rich. It just happened one morning and was fine the night before.

Answer
Hi Steve.

Strange indeed!  Usually, there are only a couple reasons for a car to act like yours.  First, check for loose connections or frayed wires at the coil, the distributor and the alternator.  Second, and I know this is opposite of what you would think given your "running rich" suspicion...insufficient fuel is reaching the injectors.  For this test, I'd de-pressurize the fuel system by removing the gas cap, then un-do "carefully" the fuel line at the rubber hose in the line before the injector rails...then have someone turn on the key.  You should see and catch a gusher full of fuel.  Anything less than that and you could have a blockage or a bad pump.

Dave