1982 porsche 928

[mrfrank]

I recently got a non running 1982 Porsche 928. The car was not running when I got would start with starting fluid so I checked fuel pump was bad replaced fuel pump and filter now the car will start then die guessing running off cold start valve only. Checked injectors no power going to them. I have clean the 14 pin connector and jumped the fuel injector relay and when I jump pins 87 86 and 30 car makes a buzzing sound in the check engine light lights up but car will still not start and run and still no power to injector any help on what to do would be deeply appreciated I am not good with electrical problems

[mrfrank]

I just now 're checked fuel injector relay I'm using a test light should there be power coming off both leads of injectors after I jumped fuel injector relay has power on both connectors of fuelinjectors

[Landseer]

To jumper FI relay it's pin 87, 87a, and 30. Need pictures posted here of old relay and the position in the panel where you believe it resides. Be very careful or you can burn the car to the ground. Its tricky due partly to bad guidance info and easy confusion about selecting correct relay position and possible previous owner wrong fixes

[Landseer]

Should have power to both leads at any given injector. Firing consists of the computer diverting one of the leads to a ground at a fast repeating rate. They batch fire all at once, but the computer and wiring actually splits the circuits into separate parallel ones.

So you need to ensure that the ground points are clean
On 84, the grounds for engine management are on the passenger side cam cover. I think 82 is the same. One ground is on a bolt near E cast in word porsche. Other is near O, buried under an emissions valve, real pita to get to but crucial.

Also replace thermo time switch, or at least test it. It is axially mounted in water bridge, it fails in a position that can keep cold start injector pumping and flood car according to what I've read.