Johnu33301

Hi All I have an 82 Porsche 928 that will not start (unless I shoot fuel into the intake), I have changed the fuel pump, filter, pressure reg (all three) ,Temp sensor, The ECU (I have a spare now) and ICU and relays. I do have fuel pressure and yes the pump works fine. I have no power to my injectors at all. I've been told I should have 12 volts at the injectors, I did notice the green wire from the distribitor to the ICU and it was cracked, I repaired it and still no start although it did seem to want to run.... I'm at a loss, I have been told to check all grounds and clean them it is my next step. Are the any Porsche Gods here that can give me any pointers!!!!!! Thanks in advance!!!!!!!!!!!!!!!

Garth S

You may find some similarities in this post here .
If not, search the 928 forum archives for other contributions, particularly by Rich9928p and Wally P.

neilh

Have you tried the fuel injection relay? It provides power to the injectors.
It is top row eight from the left, mine failed intermittently, then completely, and i had the same symptoms.

Rich9928p

You will find the steps to check out the voltage path to the fuel injectors in this post. You will even find clips from the schematics in the thread.

https://rennlist.com/forums/928-forum/207564-starts-runs-for-a-few-secs-dies.html

Rich9928p

In 1984 and earlier North American 928s the ignition system uses a Hall-effect sensor to trigger the spark system. This diagram shows that circuit. Note that it is a shielded cable that runs from the distributor to the spark control box.

If the Hall-effect engine rotation signal doesn't propogate to the spark control box, there will be no spark and the L-Jetronic fuel injection system will not function. The fuel pump will also not turn on.