TAREK

Hi all,

I posted on another thread the no-start problem I'm having... but I wanted to understand if the fuel pump is supposed to come on when you turn the ignition key, before engaging the starter or not

There are conflicting opinions on that. IF it's not supposed to come on, then someone must've done it (rigged it) in my car that way...because that's what was happening until of course, this morning when I experienced the no-start problem

still stranded, trying to figure out a way to get the car running again

TIA

'79 SC

timlooney

I know that in my 82 with the ingition in the run position but without the engine running, the pump whines. Check the relay and the fuse and see what happens.

Red 944

I'll second Tim's post

TAREK

Thanks guys. I checked and the relay is good. Strangely though, Pin 86 is always energized, regardless of ignition switch position...but then again it means the fuel pump should run, but it doesn't!

Red944,

yours a 77 with CIS, right?

96conv

Just got my '79SC fixed for the same problem. I was told by my wrench that you won't hear the fuel pump when the ignition is in the "Start" prosition until you lift up on the air flow thing-a-majig behind the air filter. This set-up prevents flooding the cylinders. Anyway, my problem was a dead fuel pump and I had the fuel filter replaced as well. Good luck with yours.

Chris

timlooney

Tarek,

It sounds like the pump may be trashed. I went through a few on my 914, I had a rusty gas tank. I have not had the pleasure of changing one on my 911 yet...

Let us know.

gregg911

I will agree with the others in all aspects. My 1980 911SC had a faulty fuel pump and I could not hear it run with the key on. You can test the pump by removing the skid plate/gas tank protection plate under the car (see Wayne Dempseys book "101 projects" article #33) and putting a test light to the pump with someone turning the key to the "on" position. If the pump is bad, no light, you can then replace it while you have the plate off. HEADS UP!!! do not buy a rebuilt pump, the pressures will most likely be off and your car will run like *&#$!! Buy the brand new Bosch pump install it and then prime the car by pushing up on the sensor plate located in the air box until you hear the pump start and feel it pump up the system, then start the car.

One more thing, you don't have to drain all the gas from the car, I used a bolt the size of the inside of the fuel line and a hose clamp, you open up the clamp, put around the fuel line then disconnect the hose, put the bolt inside and tighten the clamp. Do the opposite to get it back on. Disconnect the battery and do the job in a well ventilated area with a fire extinguisher handy and disconnect the battery.

Steve Wilwerding

Actually, the fuel pump does not run before starting the car. The whine you hear is the CDI box, not the fuel pump. The fuel pump only runs when the sensor plate is lifted, either by your hand or by incoming air.

This is a safety feature, so that if you get in an accident and the engine quits, the fuel pump will not continue to pump fuel.

If you push the sensor plate up with your hand, you should hear the fuel pump run. It makes kind of a whirring noise. As long as that works, your fuel pump should be good to go.

Most starting problems in SCs (assuming they are related to fuel) are usually caused by a faulty fuel accumulator. I was experiencing starting problems and it turned out to be the accumulator.