ozmax

g'day! firstly , I am a new member and must confess I do not own a porsche.However I have a friend who does, -a 1986 944-but doesn't have a computer.
I do have a peugeot 505 gti which uses the Bosch L jetronic injection system which I have worked on and repaired (I am a retired computer field technician) so I am familiar with it.
Now- his car is sitting idly in his shed( along with a couple of Jags). when he tries to start it it dies after a few seconds, it seems to be turning on the injectors continually and pouring fuel into the sump-not good of course. He has changed the ECU for a good one from Bosch but no change. My thoughts are that the engine temp sensor could be a culprit, or perhaps a earthing failure? the factory manual on CD assumes you have a diagnostic thingy but it should be fixable with a meter. is there a wiring harness diagram anywhere I can access? any thoughts on a starting procedure would be welcome.would be welcomed

Tiger03447

Try Pelican Parts.com tech articles or Clark's garage.com for starters. Hope this helps some.

konakat

I would say that the injector circuit is shorted to ground if the injectors are just holding open. Unplug the DME and the injectors and check for shorts to the chassis, then plug one thing back at a time and see if you find a short. The injectors are only a few ohms of impedance, so it might be a little difficult to differentiate between a short and just a normal injector.