I was doing some work under the car today and noticed the fuel pump started pumping with no key in the ignition.. What's going on, is it supposed to do that? Not leaking gas anywhere..

Thats a big fat no it's not normal. And there is no fuel pressure sensor, so even if it was leaking, it shouldn't run.
I'm assuming a FI car?

Ya it's a 72 1.7 with the Djet.. The pump's in the stock location too.. Any idea what would cause this? It was doing it intermittently and making weird noises at the relay too.. With no key in the ignition, where could it be getting power from??

I guessing another bad ignition switch, but the relay is ground switched from the ECU. So, i'm thinking the ECU is doing the same thing.

My ignition switch is brand new, I just replaced it a few weeks ago.. Also, I pulled out the power supply relay and as soon as it makes contact as I plug it back in, the pump runs until the relay is pushed in a bit, then it stops?? I'm going to take off the relay board and have a closer look at it.. I guess this is why my battery keeps discharging, I thought it was just because it was old.

Now that sounds like a relay with broken return springs.

definitely not the switch. on d-jet the pump won't turn on unless the car is cranking or running (except for a second when you first switch on.

Nothing here is making sense. If it were the main power relay the fuel pump relay still would not close. If it were the fuel pump relay there would be no power without power relay closed. Very strange. Is there any chance your fuel pump is jury rigged to an alternate power source? The coil is a common place to pick up power for DAPO who can't figure out what is wrong with the relay board.

I agree, but if you had voltage chatter over the power relay, the ecu would keep re-setting causing the pump to seem like it's cycling. But i also agree with the fuel pump off the coil idea, my car was like that when I first got it.

my bad - just checked the diagram again. The main power relay only provides power to the coil of the fuel pump relay. The contactors are supplied directly from the always on fused 12V (direct from the battery. If there is a short, or weak spring, in the fuel pump relay it will indeed run the pump.

Pull the fuel pump relay and replace it with one from the headlight motors.

Ok I think it is just the power supply relay, I swapped it out with a different one and it isn't turning on the pump when I plug it in anymore... Hopefully one of the lame auto parts stores here will have em! thanks!

Thats good, now does your pump stay running with the key on, engine not running?

You shouldn't have power to your relay board while the key is out.

Perhaps not, but that's a design issue--all stock four-cylinder 914s have some hot circuits on it with the key off, or indeed not even in the car...

--DD

The "lame" local parts stores aren't gonna have that relay. Why should they? The last car to use it was built close to 30 years ago, and Porsches aren't exactly mainstream, anyway. Get real! Call GPR tomorrow and order one up. The Cap'n

I like that LLAPS !

..................Dave D....would you list/ describe all of the hot circuits that are always on?....thanks M.M.

there are (at least) 2 hot ccts. Pin 12 and 14 of the 14 pin connector.

Pin 12 feeds the contactor side of the main power relay
Pin 14 feeds the contactor side of the rear window defogger, fuel pump, and heater fan relays.

I don't think this is a particularly bad design. They are just using relays instead of sending all that current through the ignition switch.

What does scare me a bit is that pin 12 is unfused. I have to assume that is to ensure that the car doesn't stop because of a blown fuse.

Nope, sorry. You'll have to check the wiring diagrams; anything that isn't going through a switch or a relay is going to be hot all the time.

--DD