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Dual fuel pumps on a TBI

cabledawg

cabledawg

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Anyone ever run the standard in-tank with an external as a backup? If my pump craps out in the middle of nowhere, I dont want to have to drop the tank to change pumps. It'd be nice to just flip a switch and bypass the stock with a frame rail mounted inline pump. Can this be done on a TBI? The only post I found was someone running a mech and a 'lectric on a carbed setup.:confused:
 
I don't see why not. with a switching valve and a second pump coming from the same source. a pressure regulator up top to keep pressure where it should be (around 12 15 PSI for TBI)
 
I had this setup on my 88 TBI 454 powered truck. With the in tank pump in there was too much restriction when the inline pump was working and it couldn't pull enough fuel when you put your foot into it. If I left a stop light and tried to get any decent acceleration, it would bog down and almost die on me.
 
Mines a little mouse motor and dumps too much fuel as it is, but I see y our point of the restriction.

So what if I used manual valves and a bypass inline? Or better yet, can one remove the intank pump altogether and just use an external?

Really I've only had one fuel pump go bad in over 6 years, but trying to drop the tank with 15 gallons of gas was bad enough. If this b**** was full with all 40 gallons, I'd be in a world of hurt.:eek1: It's either that or I fab up a spare tire winch to the tank and just crank it down/up:D
 
You can use a sending unit from a non tbi truck I think and use an inline pump. Just match the flow rate up with the stofck one.
 
So any of the carbed Burbs would work? I thought most of the 80's trucks still used in-tank pumps?
 
A buddy of mine runs an EFI *#%@ Jeep with an in line pump and the in tank pump removed. He used to carry a spare pump until on night on the road the pump quit. So he crawled under the *#%@ Jeep in the rain and replaced it. The inline pumps sometimes overheat. The pumps are in the tank to keep them cool. Dig that. Using gasoline to cool an electric pump. Anyway, now he has 2 inline pumps in parallel with a selector valve and an electric switch. If one quits, just switch over to the other.
 
^^^^That's my idea. Only Heeps have small tanks. Even full it'd be lighter than mine half full. So I have even more reason to want an external pump:D
 
I cut an access door in my bed so I don't have to remove the tank to swap out the pump, just seemed easier to me than dealing with all the extra plumbing etc of running a inline pump.
 
I'm thinking about that too, but one Burb has carpet and really thick insulation that would need to be removed (still easier than dropping the tank). The other Burb has all the carpet pulled out, but it's my junk hauler and stuff gets pushed in/drug out, so I'd need to find a way to make the door somewhat flush so it doesnt snag. Definately an option, though.
 
I have that thick carpeting in my Burb too, I dropped the tank, cut out a big enough hole, welded some flat 3/16 plate on the underside of the bed and filled the corrugated parts with weld. The top screws down with counter sunk phillips with some pickup cap insulation in between, It paid off the first time my sending unit went bad and again when my fuel pump quit, carpet takes no time to roll out of the way.
 
I could something like that for the carpetless Burb and reuse the sheet metal I cut out. Install the flanges underneath like what you did, but screw the original sheetmetal back over the opening to keep the floor somewhat smooth.

I think I'll still run two external pumps in parallel so If I'm the highway or something, I can just flipa switch to get going again, but I really like the floor access panel idea too!
 
I'm going to convert my 75 Blazer to TBI next month and will be doing the same deal to it, I'll post up some pics then, my cousin uses a intank pump as a primary , and has a external also on his 75 so he can just flip the switch like you want I think he used a setup from a TBI truck with dual gas tanks from the bone yard.
 
Oh and I did reuse the piece I cut out so it is still smooth for loading stuff etc.
 
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