Dual Tanks with electric fuel pump

[Fiyamayne]

Does anyone have factory dual tanks with an electric fuel pump setup? In my 86 K10 the previous owner swapped a later model 305 into it that doesn't have the cut-out to use a mechanical fuel pump so I have to go electric. Currently, it has an electric pump but I put an inline gauge at the carburetor and it only reads 3 pounds of pressure when pulling from my driver's side tank. The fuel filter is new and I even removed it to see if that affected the pressure and it didn't. The pump is mounted on the passenger frame rail. I saw where carter sells a pump rated for 14-16 psi and I thought about regulating that down but I have no idea if that would work. Any ideas or setups would be appreciated.

 

[Ricko1966]

What carburetor are you running? 14-16 is way overkill. Depending on Carb you're going to want 4.5-9 psi Carter p4594 would be what I'd look at and 33041 or equivalent fuel filter then check your pressure Should be close because the 33041 is going to bleed off excess pressure. Pressure to high? Drill the restrictor larger. If you are mechanically inclined I am doing something similar but using a cheap easy to find G9343 filter and putting a restrictor in the return line if I use a carburetor jet as my restrictor changing fuel pressure would be a matter of using a larger or smaller jet. Pumps push better than they pull,you want your pump low and near the tank

 

[Fiyamayne]

I have an Edelbrock 1406 on it. With it needing to be as close to the tank as possible should it have any issue from pulling from both tanks? Or is that really not a big issue?

 

[Ricko1966]

Shoot for 5.5 psi at idle no less than 2 psi WOT. Max pressure on an edelbrock is 6psi. I would want 1 pump per tank so I could keep my pump real close to the tank. Pumps push better than the pull.

 

[Fiyamayne]

I might look into that, I hadn't considered two pumps.

 

[Grit dog]

I might look into that, I hadn't considered two pumps.

2 pumps would work fine. If you went through the time and expense of adding in tank electric pumps from 87 or newer efi trucks.
But one electric pump down by the tanks, after the tank selector valve works great as well.
My truck engine has no fuel pump provision either. It was cobbed up with a little inline pump up in the engine bay. Idk how it ever worked for previous owners as I smoked 3 pumps in that location in a couple tanks of gas each.
I relocated another new little Edelbrock in-line pump down by the tanks.
Also installed a timed fuel pump relay that triggers the pump to prime for 3 sec when key is turned on and then shuts off until it picks up a tach signal that the engine is running.
Have been running that setup for a while now, probably 20 tanks of gas or so with no issue.
I was still planning on replacing with a better quality pump and likely a regulator as well. But so far so good with good clean power and pump near the tanks.

 

[Fiyamayne]

What model pump are you using? That would be a lot cheaper/easier than running two pumps

 

[Ricko1966]

Almost every one on this forum has had an electric pump fail.I'd run two pumps just to have the backup. And when I do a pump it's tank ,then pump then everything else because pumps push better than they pull .I want to give my pump every chance to live a trouble free life. Even the engineers think this way most pumps are in tank now,even my Ford truck has two pumps one in each tank. If Ford could have run one pump after the selector they'd have saved a bunch of money.

 

[Grit dog]

What model pump are you using? That would be a lot cheaper/easier than running two pumps

If you were asking me, idk , it’s the little red Edelbrock in-line pump. Not sure I’d give it a recommendation for longevity yet. But it works just fine.

 

[Grit dog]

Almost every one on this forum has had an electric pump fail.I'd run two pumps just to have the backup. And when I do a pump it's tank ,then pump then everything else because pumps push better than they pull .I want to give my pump every chance to live a trouble free life. Even the engineers think this way most pumps are in tank now,even my Ford truck has two pumps one in each tank. If Ford could have run one pump after the selector they'd have saved a bunch of money.

Agree 100%. There are some external pumps that are rated to pull 2’ of liquid head. But if I was going for the most reliable setup I’d do an in tank pump in each tank.

 

[Ricko1966]

@Grit dog keep us posted on longevity. I'll do the same my fuel pump lobe is worn off,so I'm using an airtex pump,I'll try to find the number. Anyway I would not buy an airtex from rockauto but that's a different story my airtex E8090 from summit has been working since June 2020

 

[davidv07]

I bough an 83 last December that had been swapped with a crate 350 and Edelbrock 1406 (no mechanical pump access). It has factory dual tanks and electric fuel pump mounted on the passenger side frame rail just forward of the tank selector valve. It had the "Mr. Gasket 12S Micro Electric Fuel Pump" installed when I bought it, but was leaking slightly from thread insert for the filter. I changed it out with a red Edelbrock pump but it didn't last long. I thought I may have got a bad pump, and tried another one and it failed as well. After I researched possible reasons why, I bought the same Mr. Gasket pump that was on the truck originally as it working fine except for the small leak. I also read the fuel pump can burn up if the ground is not good and it was recommended running it directly to the battery negative, so I did that. Since the pump was on the frame rail, I noticed the exhaust pipe passed really close to the pump so I made a heat shield and installed. So far I haven't had any problems over the last 6 months. In regards to tank and pump location, as previously mentioned, the fuel pump is mounted on the passenger side and as of now, I only use the drivers side tank (right side is rusted inside and need replaced) and haven't had any problems pushing fuel to the engine from that tank. I don't have a gauge so I don't know the pressure at the carb.

 

[GaK10]

I have an 86 K10 with factory dual tanks. It’s been sitting for a while and I’m trying to get it back running. I have a Holley Red regulated at 6psig going to an Edelbrock 1406. In the future, I will be rerouting my pump to get closer to tank level but mine is mounted to the fender well.
I’ve had some bad fuel and junk in my lines which I recently flushed out and some experiences to share. I took an old clear inline filter and put it before the pump during the clean out. The online did affect the pressure to a point where the regulator wouldn’t read. I went to NAPA and bought a large 2 micron filter and a base. I put the setup before the clear inline to see the color the gas before it entered the pump…… Anyway I took off the clear inline and left the large fuel filter (needs to be mounted). The large filter allows well regulated, consistent, stable pressures.

Fuel line Options

What options are there to remove the trash from the lines without hard line replacement? Now for the back story. I had bad fuel in my tanks after sitting for years. The tanks/sending units have been replaced and the carb was cleaned. When I went to start it, it would fire and shut down...

www.gmsquarebody.com

 

[sgrinavi]

What model pump are you using? That would be a lot cheaper/easier than running two pumps

I just put this one on after fooling around with cheaper ones. An acquaintance of mine that works on high end imports uses them on customers cars. I have just the one right after the selector valve. No issues drawing fuel from the drivers side.

You must be registered for see images attach

https://www.amazon.com/dp/B08WHV3FTD/

Edit - Don't abandon your return, I put a regulator on that had provisions for the return line. Made a difference.

 

[Kasey 1977 K10]

I did an EFI conversion on my '77 using mostly '86 parts and don't have any issues. I tried using an inline pump but because of the saddle tanks and where I could mount the pump was trying to do too much work. Take a look at https://www.gmsquarebody.com/threads/tank-replacement-for-efi.24131/page-2#post-472294 which shows the parts list I used.