electric fuel pump problems...

[32 Chevy]

I have tired a couple of different electric fuel pumps on my daily driver 56 wagon with carbureted 5.0 engine.

The problem is that the pumps (diaphram type, two different manufacturers) sound like they are always sucking a bit of air. I remember other cars running electric pumps and the pump will shut off or just tick once in a while when at idle. However both pumps I have tried sound like a machine gun for a few seconds, then shut off as the system is pressurized, and then will start machine-gunning.  The pump will continue to cycle like this even at idle. The noise is quite irritating and does not seem 'right'.

I'm using the stock 56 Ford tank which was completely cleaned and sealed before installation. The pickup is at the bottom of the tank and then the line comes about 6" above the top of the tank to prevent siphoning and the pump is located on the frame rail about the same level as the tank. The line seems clear inside the tank because when I blow into the fuel line from the pump location it does not require much pressure and I can hear bubbles in the tank. When I installed the pump I purged the line by running the pump disconnected from the carburetor and got very good flow.

Any ideas?

Thanks,
Dave R.

[donsrods]

What brand and model pumps?  I am running Holley red pumps on both my   '27 and daily driver Jeep, and one has been on there for 12 years and the other for 3 years, no problems.

I think the problem may be that you think they should not be cycling as much as they are. The Holleys I am running run at full bore all the time, and the one on my Jeep sounds like an air compressor. Everyone who rides in it says "what is that noise" and if you stand outside the jeep you can hear it running.
I don't think the one on my roadster was that loud, but over the exhaust you couldn't hear it anyway.

If you have bought the ones they sell at the auto parts stores, I think they do run and then shut down to a tick, but other brands may perform differently.

One bit of advise I can offer is RUN A GOOD QUALITY FUEL FILTER BEFORE THE PUMP. Electric pumps don't like dirt. I am running water/seperating fuel filters on both cars (I work at a Marina, so boat stuff is a natural thing for me to install) and once a year I toss the spin on filter and put on a new one.

Also, make sure your filter and pump are located close to the tank, and that you have gravity feed to the pump (electric pumps don't like to self-prime) Mount the pump lower than the tank outlet if possible.

I just read on another thread where someone suggested putting rubber under the mount, like you get on those muffler hangers, and I am going to do that on the Jeep, because the pump is getting louder.

Post what brand pumps you are using, and maybe someone on here is using one of those and will have better info than I have given. You could also get on line and ask the maker of the pumps if that is the way they work.

Good luck. Don

[32 Chevy]

Well, I checked the pump closely and saw just a drop of gas on the inlet side. So, I removed the pump and tightened all of the various screws holding the pump together. Then I reinstalled it on the frame using a double rubber mounting; I bolted the pump to a piece of thick conveyor belt type material then then mounted the belt to the frame with a different set of bolts. That way it isolated the sound of the pump ticking from echoing on the frame.

I made sure the flex lines were secure and as soon as I hit the switch the pump pressurized immediatedly with barely a sound. Operation succcessful!

Dave