Help please. Holley Red electric fuel pump won't stay primed.

Hello all, I'm stuck and at my wits end. My fuel system won't stay primed. It's a Holley "Red" electric fuel pump, mounted below the reproduction 32 Ford fuel tank. When I flip the switch, you can hear the pump spinning, but it won't even start pumping until I walk back to the fuel tank, take off the cap and blow into the tank at the filler to pressurize it, then you can hear the pump sound change to a lower growl and it begins pumping. The engine will start and stay running only for a few minutes until the WCFB's run out of gas. When I go back to the tank, I can hear the sound is higher pitched again (ie just spinning, not pumping) and I pressurize it again, then the sound changes to the deep growl and it pumps again for a little while. Thanks in advance for your help.




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You need a fuel tank vent, or a vented cap.And if you keep running that pump without enough head on the inlet, you will fry it.

 

That or the pickup tube or feed hose has a hole or crack pulling air.

 

If that were the case, opening the cap wouldn't temporarily fix it.

 

The tank has a vent tube; I've also run it with the cap off, same result.


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I was running the same pump and had a similar problem so I opened it up and found a bit of debri inside. I cleaned it and it was fine. Also your inlet and out is correct right ? Dumb question but I put it backwards one time hahah.


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I opened this one up too, but it looked clean inside. Yes, the inlet and outlet are facing the correct direction.


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Also try running the pump into a gasoline container just to make sure it's pumping fuel. Just so you know it's not the carb because you can have a small clog by the float needle and seat. So some fuel might be getting to the bowl and once it fills it, it can't keep up with the motors demand. I had that happen to me before and had the same symptoms.


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It's pumping fuel. The problem is that it won't stay primed, it pumps for a little while, fills up the bowls but won't keep pumping. When I go back again to put air pressure to the fuel tank, you can hear the pump change tone, and it's begun pumping again but after a bit, you just hear the higher pitched "spinning" but not pumping.


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My pump makes the same noises and it gets higher pitched as the float needle opens up again once it fills it almost cuts the noise level so low you can't really hear it. Then once float opens up it winds up again. And if I'm looking at fuel filter it stops flowing when the bowl fills. Then flows as it opens up.


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Sounds like there must be a restriction between the tank and the pump. Do you have a rubber line between the tank and the pump?? Maybe it has deteriorated due to the ****ty ethanol gas we are forced to use, and causing a blockage. Just a guess on my part, but it's a possibility.

 

It has two WCFB's, so I wouldn't imagine both needle and seats having the exact same clog as you mentioned. I rebuilt the carbs recently, should be pretty clean.


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I took mine off my truck and I'm running a mechanical but if you need another pump let me know I might sell mine or trade for a set of valve covers. Hope you can figure it out .


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My experience with electric pumps is they can't draw through a fine filter. Is that a pre-filter we can see? if so I think it needs to be 100 micron. Just try to run the pump with no pre-filter. If it runs you'll know it's the filter.

 

It has braided steel fuel line the entire length of the ch***is. Though, it's rubber inside the braided steel, right? The rubber line you see in the photo at the beginning of the thread is brand new aero quip fuel line, as I just recently relocated the pump lower to see if it would cure the problem.

If the ethanol in the gas has deteriorated the rubber line, would it crumble and create blockages? The thing that gets me curious though, is if I slightly blow into the fuel filler to pressurize the tank, it starts pumping. Plenty of gas seems to get to the carbs at first....it just won't maintain the prime.


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Well, I'm certainly no expert (at much of anything)...but I would be tempted to purchase a length of rubber tubing long enough to make temporary connections, byp***ing the fuel lines you have installed. See what happens. The tubing shouldn't cost you much money, and it would prove conclusively whether the installed tubing is causing your troubles, or not. At least you would eliminate the tubing as the culprit, if in fact that was the cause of the problem. Good luck! And let us know what you find.

 

Yes, that is a pre-filter. When I got the car, it had a Holley "Blue" pump on it and I drove it around without fuel flow problems with the same pre-filter. It had too much pressure though, even with the pressure regulator for the WCFB's, so I changed to the "Red" pump and low pressure regulator.

All that's inside the whole aluminum housing for the pre-filter is a flat screen disc at one end. Not sure what micron rating it is. If I'm not mistaken though, the Holley instructions say to use a pre-filter? Also, inside the tank, there is a sock over the end of the fuel pickup at the bottom.


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See post#2. Run it with the gas cap loose and report back.

 

I mounted my fuel pump on the frame rail which is a little higher than the fuel tank on my deuce. HRP

 

May not mean nothing but, on the tri five cars I work on I remove the sock. We had a terrible time several years ago with the socks collapsing and cutting off the fuel. I always add a metal filter along the frame in the gas line. The socks then would just collapse and stick together and sorta seal them selves together. I'm sure it was reaction to the good ole modern gas.

 

It sounds like the pump is pulling air from s0me place, old tell if it can get air it will leak fuel. move your clamps back closer to the yellow stoppers. Next thing I would do is get a gas can and take the hose off going to the carb and let the pump run moving gas from the tank to the can and watch it to see if it starts getting bubbles as it stops pumping that means it is getting air from some place And it could be internal. You could be the lucky guy that got a bad pump out of the box. good luck

 

First off get rid of the sock filter. You already have a filter in place. These type of pumps don't like to lift liquids and it may be cavitating by trying to lift the gasoline and losing it's prime.

 

See post #5

I've seen a similar problem with a Holley red pump 30 years ago. We ***umed it was ****ing air but couldn't find anything. We ended up using a fuel filter that had a return line to the tank and it solved the problem. My thought was that when the pump is turning in the unmoving fuel it heats the fuel and vaporlocks itself. Having a downstream filter that returns to the tank allowed fuel to keep flowing and cool the pump.

 

Sorry I missed it. Thanks

 

Thanks for the ideas guys. Next weekend I'll pull off the fuel line right after the pump and pump the fuel into a bucket and see if keeps pumping nonstop (meaning a problem downstream) or still loses its prime and has air bubbles. Next, I'll drop the tank, pull the pickup out of the top and remove the sock.


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Hi guys, got back into the garage today to work on diagnosing this problem with your suggestions. Disconnected the fuel line right after the pump (less than a foot of brand new aeroquip rubber line before the braided system that runs to the front). Switched on the pump, it's dry until I pressurize the fuel tank from the filler neck. The sound changes, it pumps, but only as long as I'm pressurizing the tank. Fuel stops pumping immediately after pressurization stops.

What do you guys think, would the fuel tank pick up sock be that restrictive to immediately cut off fuel supply? Or do you think it could be a defective pump? Before I pull it all apart to drop the tank and remove the sock...


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It sounds like the pump is shot and not able to pick up the fuel. When you pressurize the gas tank the gasoline looks for the only way out and that's through the pump. If the sock were plugged you wouldn't be able to push the gasoline to the pump. You'll need a new pump but what needs done first is to drain the tank, drop it out of the vehicle, have it flushed out good and add then add sump to the bottom of the tank along with a good sized fitting and hose so that you always have a supply of gasoline to the suction side of the pump. Your present pump MIGHT be ok to use with the new set-up, but when they run dry, like yours has multiple times, it does a job on them and a new one is in order. Your pump may have worked for a while since the clearances were tight and it was able to lift the gasoline, but these pumps aren't meant to lift liquids.

 

Thanks for the advice Andamo. Yes, the pump has definitely run dry multiple times.

Sorry if this is a rookie thought, but how about using this (see attached picture) area for the fuel delivery? It's the lowest point on the tank and has a fitting already. (Reproduction '32 fuel tank).



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I installed a one way [check] valve in the line after fuel line exits tank and before the filter to prevent drain back to tank

 

That would be perfect. Just try and use a elbow and keep things as close to the tank as possible. Now you'll need a way to safely drain the tank for the fitting installation. If it's possible I'd try installing a valve before your filter in case you need to clean/change your filter you could just shut the valve and not drain the tank. And a added benefit would be anti theft device while the car is parked with the valve shut.