Vandit

If I turn the car's ignition to "on" w/o actually cranking it over, will the fuel pump run and allow me to see if I have a fuel leak at the fuel filter?

I replaced the fuel filter yesterday, all appears to have gone well, but I want to make sure my unions stay nice and dry before starting the car.

vagluv

It should. That's what primes the pump. If the system doesn't pressurize the pump keeps running.

ValveFloat

The pump will only run briefly, if you want to run the pump continuously you need to pull the fuel pump relay and jump two of the terminals. I don't remember which terminals off the top of my head.

f@tboy

I thought the pump runs only when the crank sensor detects the engine speed to be > 30rpm?

axl911

If the 964 operates the way the 993 is, it won't. I am pretty much certain it won't. The fuel pump will run only when engine is running or cranking. The DME relay has 2 relays inside. First one is for the DME power itself. Second one is for the fuel pump. Safety thing.

If you want manually run the pump, jump the DME relay. I do it all the times to test the pump and leaks.

Navaros911

You need the engine running... you can hear the hydrolic brake system humm when you turn the key to on. It should stop after a little... but the fuel pump should be quiet.

Vandit

Anyone have detailed instructions on how to jump the DME relay?

I never got around to doing it after the fuel filter replacement, but this time I will have replaced all fuel lines and have undone and retightened all the unions throughout the engine compartment, so it's very critical I test for leaks before even thinking about cranking it over.

newsboy

Remove DME(fuel pump relay) R-41 and jump a wire across # 3 & 7 . This should run the pump.

HiWind

Thanks newsboy!