hwyengr

You shouldn't be hearing the fuel pump unless the engine is running. In an accident, 928s don't use shutoff switches for the fuel system. Instead the pump relay is switched from a signal from the ignition system, so if the engine isn't turning, the pump isn't running.

So, if your pump is running with just the key on, something is screwy in your wiring. Replacing your relays would be a good first start.

Callum_GT

not sure I agree with last! my 1980 4.5l fuel pump will come on if ignition is on regardless if engine is running or not, seems to turn off when it gets to pressure though and this can be before I start her up.

dancingduke

Thanks Mr Merlin.

I didn't get a chance to drop the tank out yet, I've been busy getting an old classic ready for painting next week but I will do it this weekend.

Just have a quick question. Should the fuel pump start pumping when the ignition is on or should it just pump when turning over ? It pumps with the ignition on continously but I don't think it pumps when it's turning over.

Thanks again and Happy Paddy's Day !!!

dancingduke

Thanks again guys,

Oh ok,

My pump isn't shutting off at all even if I leave it for a few minutes, just runs and runs. So do you think that means the fuel pump needs replacing ? Going to replace the relay anyway.

Callum_GT

Mine did that once! Turn out I was out of fuel hehe

hwyengr

The L-Jet is the only one I'm not 100% sure on, but the K-Jet cars got a signal from the distributor and the LH-Jet cars got a signal from the crank position sensor. The fuel pump on those models does not turn on unless the engine is spinning.

If your pump is running all the time now, I'd bet highly that the relay fused itself closed since the power for the pump comes from the always-hot 30 bus. The pump is probably fine, just see what happens if you change the relay. If your horn works, it's the same generic relay, so you can use that one for testing.

On a side note, if your pump has been running continuously, it might not be a bad idea to pull all the plugs and make sure you don't have a leaky injector that has filled a cylinder up with gasoline, or else you're gonna have a nasty surprise the next time it fires.

dancingduke

Problem Solved, woohooo !!!

Thanks everybody for all your help, greatly appreciated !

Haven't been on in a while as I was waiting for the fuel pump relay and filter to arrive. When they did I put them in, the fuel pump now runs for about 8 seconds and shuts off. But didn't start. I bought a cheap fuel pump (Meat & Doria 76050/1) that cost me $85. I had my doubts as it was inexpensive but after a bit of priming it fired straight up. I also have a Bosch on order.

The car runs and sounds great but has a little ticking or tapping coming from the engine. I have to explore this a little more.

Thanks again everbody !!!

Paul

Donald Smith

Your valves may only quiet down after a half hour or so. They take some time to prime properly. Congrats on getting it running.

Don

Wisconsin Joe

It could also be normal injector noise.

They are pretty loud.

And if you aren't used to how loud they are, you tend to worry (at least I did).

Jersey_Sam

Same scenario here, just got an 81 928 manual, delivered today, and the engine turns but doesnt fire. Cluster is dead, except for the "coolant" light on.
I pulled the carpet back and all the fuses are damp and some are corroded with white deposits. Some fuses were glued by this white powder stuff. I guess i will be following this thread closely. thank you all.

Sam

ltoolio

Looks like you might have some questionable splices going on there, too...

Jersey_Sam

you are right Ryan. Getting rain tonight through Monday. the car will be dormant. Bought some Electric Contact clearner and all brand new fuses. Will be cleaning with a wire brush the contacts, and then install new fuses accross the board. next is the relay. Hopefully, the cluster should come back to life after that. if not, i will do some more research and find out how to tackle the cluster.
One step at a time. thanks Ryan.

dancingduke

Hi Sam
When I was doing mine some relay contacts broke in place because they were corroded so I had to take the board out.

I thought it was going to be a pain in the *** to get them out but was quite easy. Where the broken contact was I just turned the board over and through the bundle of spaghetti wires ( BEING REALLY CAREFUL) found the back of the relay with the problem and the connection then using a small flat head just tapped the broken piece out just far enough to pull it out with a pliers, while spraying the contact cleaner at regular intervals.

I'm sure there's a better and safer way but this worked for me.

Oh I also used a small flat file to clean all the relay sockets while I was at it.

I also had to take out all the seats, center console and carpet to get at the sound proofing on the floor. I was soaked and smelt like a wet dog with bad breath. Dried it out and its fine now,
Best of luck
Paul

Jersey_Sam

Paul,

Thank you for the tip. Might hit you up if I need some more advice or pictures. I'm also new to these cars.

Thanks,
Sam

Wisconsin Joe

There's a really good writeup on the CE panel.

http://members.rennlist.com/sharkski...04-Bzzzzzt.htm