Ok I picked up a 78 Econoline from a friend with dual tanks. I got the van for free so i can't argue, it runs good, but has an issue, it will at complete random stop getting fuel to the engine. The filters are all new, etc. I think the issue is the way he plumbed in the dual fuel pumps.

The van kept eating up mechanical pumps, so he installed a pair of electric pumps. There is one pump per tank, between the tank and the selection valve. Then it goes from that valve to the mechanical, then to the engine. I know the connection to the mechanical won't do much, but I think the issue is with the way the electric pumps are hooked up. To top it off both electric pumps are hooked up to the ignition switch and not to the tank selector switch. It seems to me that these pumps would be fighting each other. The other interesting part is, that either pump will work for either tank. This problem didn't exist before he added the electric pumps. The problem also didn't pop up until a year or two after he installed the electrics I believe. Needless to say this causes questionable reliability issues. If you wait a few hours, the van will fire back up. He was thinking that it's the pickups are clogged, but if the van quits getting fuel, and you switch tanks, it still doesn't get fuel, which would mean that both pickups clog at the same time every time, and that doesn't sound right to me.

Looking for other opinions on this. I'm thinking of removing both electric fuell pumps and just installing a single one between the valve and the engine. I think this would cure the problem. Any other idea's? <!--IBF.ATTACHMENT_762139-->

 

Do you have the tanks properly vented? Vacuum stopping fuel being pumped?

 

From what i have been able to tell the vents in the tanks seem to be operating properly. The interesting thing is, it's completely random, it could be months without an issue or just a few days.

 

Remove gas caps,

Attach a fuel pressure gauge close as you can get to carburetor.

Monitor it and see what it says when it actually stalls.

 

> so he installed a pair of electric pumps

First wire it up the correct way AND install relays.

Second, where are the pumps located? If they are not below the gas tanks you will have weird problems and will eventually burn them out.
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You probably have a 60 amp alternator and it might not be providing enough juice to the electric fuel pumps especially if both are drawing power at the same time.

 

You are much better off to have the tank pumps manually switched so only one of them are on at one time...

 

1. In order to put a pressure guage next to the carb and see what it says when it stalls, would be VERY troublesome, as it stalls at random, it could be days or weeks, or months. Good suggestion though, just not feasable.

2. The pumps are wired up with relays, I thought that would have been a given, but that was my bad. Sometimes I tend not to be as clear as I should.

3. The pumps are located between the tanks and the valve. Also each pump is below the bottom of each tank.

4. The alternator is actually a 90 or a 120 amp, I don't remember which.

5. One at a time is what I was thinking should have been done, but I thihnk I'm going to remove both from their positions, and just put a single one between the valve and the engine instead. I might stick a filter in place of each pump. Perhaps a marine filter since they have watertraps as well. I just have to wait for the weather to clear up a bit. Soaking wet out here. Of course it's the Pacific Northwest, so I'm not gonna hold my breath. LOL.

 

Sorry Fant, don't mean to hijake your thread, but since were talking about the same issue...

I also recently bought a 91 5.0 E150 Clubwagon. Both tanks were rusted out, so the guy put in a new tank (rear only) with a elec pump right at the tank AFTER an inline fuel filter. The fuel lines bypass the tank selector switch, to a second filter, and second pump, both located directly under the driver door on the frame.

Works great, but when I want to replace the second tank, I assume I'll be plumbing it the same way? So, how do you\would you 'manually' switch between the 2 tanks?

Thanks, Greg

 

Manually switching would be just hooking up the pumps to the manual switch inside the cab.