Electric fuel pumps

[Sinister]

When I get around to swapping motors, I might be needing to go with an electric fuel pump. Anybody running one? What's your setup? Pics if you got em.

[#169fan]

I just installed one on my 1969 GMC.It works great.I used an ACDelco pump.Its PN is ACD#EP12S or GM# 19162977.Extremelly easy installation.I don't have any pictures, but I installed the pump in the frame under the cab.Then I took off the stock pump and replaced it with a block off plate that can be purchased at just about any local parts store.You will also need to put a filter between the pump and the tank to keep any debris out of the pump.I would also recommend installing a pressure safety switch.Pressure switch part # is A-68301.

[Sinister]

How does the pressure safety switch work?

[LONGHAIR]

It cuts off power to the pump when the oil-pressure drops below a certain point.

[petey-pablo]

I Also Have my Fuel pump in the frame under the cab Works great. Heres some pics. Mine is a Holley Blue Part Number: HLY-12-802-1 From Summit. I am not sure if Im uesing a Fuel Pressure Safety Switch I have to look into that, SOUNDS LIKE A MUST! Picture quality isn't that good I used my Cell PhoneCamera!

[#169fan]

Here is an instalation diagram for the installation that I spoke of the other day.

[68 short step]

another vote for holley blue, i run that on my firebird

[deputyd_0803]

I am running a Holley Blue on my 72 c20 and have it mounted just like Petey's.

[Sammy]

I used a Delco in the GMC. First tried to put the pump on the R/H fender well area thinking ease of mind to be insight etc. But when using a blazer underbed tank found it was struggling to keep up. Ended up moving it to frame rails closer to the tank now she operates great.

[gophersnake]

I came across this old thread while Googling for other info about fuel pumps but I do have some interesting tidbits to share:

After going through two or three mechanical fuel pumps in 20 years or so, I found I couldn't get them any more so I settled for an ACDelco EP12S. That was in 2002. It worked fine, no problems at all, then quit cold a few months ago. It's not that it was pumping badly -- something electrical seemed to have failed inside, because it no longer showed any signs of life at all.

The first replacement I found for it was a black, plastic-bodied import with the Mr. Gasket brand. Unlike the EP12S, the instructions said to mount it low down near the bottom of the tank. It could push gas just fine but (so they said) couldn't reliably lift it any higher than 12". I didn't like the idea of working under the truck any more than I had to, especially with gasoline dripping in my face, so I mounted the Mr. Gasket pump on top of the wheel well -- right where I'd had the EP12S, and at about the same height where the old mechanical pump had been.

The Mr. Gasket worked fine for about two months. The other day, though, I started up a hill with a low tank. Right away, the pump quit and left me stranded. I added a couple of gallons of gas but that didn't help. I found out later that the pump had probably lost prime. When I'd first installed it the tank had been about half full and the pump had managed to prime itself. Under these slightly more difficult conditions, though, it couldn't until I helped it out by sucking gas through it with another pump. After that, it seemed to work well enough to let me idle the engine for a few minutes.

I found I could get another EP12S the next day, so rather than risk getting stranded again, I just left the truck parked while I waited.

This time I installed the two pumps side by side, still on the wheel well but with the Mr. Gasket a few inches below the ACDelco. This way, if either one gave me any problems (now or in six years), I could quickly change to the other one. Just as well, it's turning out!

As I expected, the ACDelco has no trouble priming itself, even from dry and even with the same low fuel level in the tank. The instruction sheet said to mount it no higher than 24" (not 12") above the top (not bottom) of the tank, so I'm definitely in compliance there. On the other hand, the ACDelco seems to overwhelm the float needle -- my carburetor runneth over!

When I switched back to the feebler Mr. Gasket, it had lost prime again just from having its fuel line disconnected. The carb didn't run over this time, though, so I'm thinking it may be the EP12S, not the float needle, that's at fault. It occurred to me later (after dark!) that I haven't actually checked the output pressure of either pump. I should be able to do that in the morning. I may even have specs somewhere for what the normal pressure range is on a carbureted engine.

If the pressure looks normal, I'll try changing the float valve first. In case it's high, though, what's the easiest way to tame an electric fuel pump? I'd guess that the pump has a built-in pressure switch which, in this case, could be acting flaky or could be set too high. I'd love to add an external pressure switch to keep tabs on the built-in one, but where could I find one?

Not that it makes a whole lot of difference by now, but the truck is a '68 GMC C2500 with a 351 V6 and a Bendix-Stromberg WWC (2-barrel) carb.

[gophersnake]

By the way, I didn't realize that block-off plates (for retiring a mechanical pump) were even available. I just naturally made my own from an electrical box cover and some gasket paper.

[gophersnake]

Finally seem to have it all resolved. There turned out to be three problems, not just one:

1. The Mr. Gasket pump really is feebler than the ACDelco. Mounted where it is, if it loses prime when the fuel level in the tank is low, it may not be able to prime itself without help. That was why it cut out soon after I started up a hill the other day. Once I prime it (by sucking gas through it with another pump) it's OK again. The new ACDelco is much better at priming itself. The old one was, too, when it was still working. The difference is probably in the technology; the Mr. Gasket whirs, the ACDelco goes tock-tock-tock.

2. The ACDelco was not producing excessive pressure. It built up about 6 psi, compared to 5 for the Mr. Gasket. There was crud in the fuel line going into the carb; when some of that got between the needle and the seat, the float bowl overfilled. That may have happened a few times while I was using the Mr. Gasket, too, but not as dramatically -- and not while I had the hood up to see it.

3. It turns out that the last time I took the top off the carburetor, I didn't get the gasket in quite straight. There was an unsealed gap at one corner of the float bowl where gas could escape if the level got too high.

[Lippyp]

I have a carter electric pump, mounted on the outside of the frame rail under the passenger door with a cheap inline filter between it and the tank. It works fine although it is a bit noisy even with rubber mounts.

[1956cameo]

I have an electric fuel pump for my 72 suburban. A tad noisy but works like a charm. I don't know what brand it is but it was about $42 thru Autozone. Looks just like the one in #169fan's diagram. Has a built in fuel filter; and I wired it to not pump when the ignition is turned to accessories. Make sure you do this or else it will not be able to have your radio on with the truck off without the pump running. Of course after I bought the pump and installed it I found a working electric fuel pump under one of the suburbans seats, then found another working fuel pump on a parts truck that I have. Oh well at least I have back ups.

[BP68]

Last page of my build thread has a pic of my setup. Jeg's pump with metal lines from the part store, one rubber hose from blazer tank sender to metal feed line, then some stainless braided line from frame to filter to carb. Russell make a nice stainless tube with filter to go from carb to braided line depending on your carb. Got it from Jeg's also.

[gophersnake]

Well, I only thought I was out of the woods!

The ACDelco pump mounted on top of the wheel well worked just fine in cool weather. As soon as we got a warm spell with temps in the 60s, though, it started losing prime -- vapor locking, apparently. I have no idea why this ACDelco did, when its predecessor (same model, mounted the same way) never did in six years. I also don't understand why mechanical fuel pumps don't seem to have the same problem.

I finally caved in and moved the ACDelco down to the frame rail. It's only been there a week but so far, so good.