Porsche Enthusiasts Club Forum

Hi all I took my 85 928 to a golf club 20 miles away drove it in to the car park yet when I returned to the car 4 hours later it would not start.I had to have the car towed home.
I have tested the spark and thats OK and tried starting the car with the fuel pump relay shorted out so that the pump runs continuously.The car started once and ran OK until I shut it off since then it has not restarted.
Does anyone have any experiance of a similar problem before I start dismanteling the fuel system.

Les

Hi

As shorting the pump worked, even for a short time, I would suspect the pump or possibly the relay, but the 928 pump is a known problem on 928s...

WHEN was the fuel filter (under the back)...last CHANGED ??? as it could be blocked if not changed for years...

Hope this helps

All the best Brett

Hi Les,

When you jumper the pump relay, can you hear the pump running?

How about fuel pressure? Can you get hold of a fuel pressure gauge to attach to the test point on the fuel rail?

Maybe fault in fuel pressure regulator or fuel dampers. Disconnect vacuum lines from these components to see if there's any fuel in the lines, which would indicate failure of diaphragm.

If you re-started with the pump jumpered but couldn't subsequently then this would suggest the problem is not with relay, but there may well be an intermittent problem with pump. Another thin to check if it doesn't run when jumpered is to take off the pump cover (back of fuel tank) and check tightness of the +ve connection to pump.

Many thanks for your replys I'm working my way through them I will let you know what I find'

Les