Care to speculate on tbi fuel system plumbing?

[Overland]

I'm attempting a minimally invasive installation and would like to leave my fuel tank alone entirely. The idea I have is to install a filter housing on the inlet of a frame mounted pump, and to route the return line to the inlet side of said housing. Most mechanical diesel engines I've been around were plumbed this way for injector pump cooling.

I've been away from here for some time, but I recall discussion of fuel heating through pumping it across the regulator and speculation regarding an inline cooler to remedy the condition. My tank is going to stay behind the seat, and is only plumbed for suction, of course from the top. I think routing to a filter would be quieter in the cab and wouldn't heat the fuel in the tank, if the pump can pull fuel across a filter after lifting it up the pickup tube.

I feel like once primed it should work, but you could fill a warehouse with things I don't know. Please alert me should it seem my logic is not firmly based in reality.

[dave w]

Thoughts, ideas, options, and experiences about remote mounted fuel pump and return fuel locations vary between members.

Frame mounted fuel pumps are OK. In-The-Tank mounted fuel pumps are optimal. Routing the return fuel to the bottom of the fuel tank is optimal. . . just like factory.

[ralmo94]

Some fords use frame mounted pumps. Just make sure it's lower than the tank and not mounted were it would snag anything. I personally don't see fuel heat being an issue with a return line you are not very likely to vapor lock. That's my $0.02

[Overland]

Ford to my knowledge utilized a fame mounted booster pump to supplement the in tank pump in the 80s, where a truck with two tanks had three pumps. In my admittedly minimal experience there, the booster won't work on its own, or at least not sufficiently. That is, pulling fuel through a dead pump in the tank.

I'm considering something like the Carter P5001 suggested on the swap info page here. I'm not a fan of remote pumps, but with the tank in the cab, I'd rather not listen to it. I know someone likely sells a bolt in solution ready for an in tank configuration, but I'm also operating on a minimal budget and would prefer to maintain any original parts I can.

I have a picture in my mind that looks very clean, but that doesn't matter much if it doesn't work. I figure this is the best place to hear of other's trials and errors.

[Overland]

This is in a 62 C10 if it assists with your visualization

[ralmo94]

Ford to my knowledge utilized a fame mounted booster pump to supplement the in tank pump in the 80s, where a truck with two tanks had three pumps. In my admittedly minimal experience there, the booster won't work on its own, or at least not sufficiently. That is, pulling fuel through a dead pump in the tank.

I'm considering something like the Carter P5001 suggested on the swap info page here. I'm not a fan of remote pumps, but with the tank in the cab, I'd rather not listen to it.

I was thinking of the van pumps that you can buy one at the parts store for about $60 usually in stock, pretty sure it's for single tank configuration and has barbed fittings on it. I used on on my motorhome to get it parked when the in tank pump died. These are made for 90 psi 40 gal per min and economical. I don't think you would have a problem with one using the cab fuel tank, as gravity would keep the pump primed plenty easy enough.

[Overland]

Cheaper than the Carter for sure, similar in appearance, like an in tank pump with barbs. The Carter has threaded ends making barbs optional. I'm imagining a soft line between the hard line where it exits the floor and the filter housing, then hard line to the pump, and preferably utilizing the original tbi fuel hoses from there.

Would the fact that the fuel tank utilizes a pickup tube from the top cause difficulty priming at low fuel levels?

[dave w]

Perhaps the attached FITech instructions will be helpful.

[Six_Shooter]

I see fuel pressure regulation issues if you are T-ing the return line back into the fuel pump feed. This IS a restriction and restrictions, even ones that could potentially flow both into and out of the tank will cause issues. Even if your pressure seems to be what it's supposed to be, I could potentially see a problem with reliable fuel supply due to the feed from the tank needing to flow both into and out of the tank continuously.

It's not difficult to add a return line to a sender unit. A drill, some hard line and someway to seal it up, which can be something like JBweld, or epoxy will create a trouble free system that you won't have to second guess.

[Fast355]

I had one of those Ford frame mounted pumps when I first converted my 83 G20 to TBI. It was garbage and loud. It lived a short life without the boost pump supplying fuel to its inlet. I switched it out for a TBI van tank and fuel lines. Used a Vortec fuel pump on the TBI sending unit.

[Overland]

I think it comes down to the suction side. Every high pressure pump I've ever seen had the return ported back into the pump inlet. The difference is pressurized or gravity supply. There's always fluid at the inlet. If the tank had a bung in the bottom, I think it would be okay.

Cavitation will kill it in short order for sure. Also, I think I'd rather pay more for a low pressure pump than try to make do with the excess volume, and probable noise, of a higher output model.

My primary goals here are reliability and economy. It's getting single exhaust. Totally stock Suburban engine, zero illusions of high performance.

Also not changing the location of the tank. I know it's popular, but I wouldn't have a filler in the bed even if there was room underneath for a fuel tank.

[Overland]

I'm surprised to find that a drop in sending unit for the original tank is not common, nor does it even appear to be available in the aftermarket. I didn't see one tank or sender set up for fuel injection to go behind the seat. I guess this is why the average guy puts a fuel cell under the bed in place of the spare. The market caters heavily to that.

[dave w]

1960 - 1966 Chevy Pickup - Fuel Sending Unit: https://www.tanksinc.com/index.cfm/p...rod/prd712.htm

[Overland]

Lots of those, nothing equipped with a pump or accommodation for extra wires and return. I'd modify the original before buying new, especially if I need to modify the new one anyway.

I didn't look long, but I'm honestly surprised it didn't show up on the usual sites alongside original equipment style.

Looks like I can get a replacement Suburban pump for ten dollars on rockauto to use for.mock up and testing, then tank flushing.

[dave w]

A return line similar to the picture below is both low cost and the optimal return line solution.
Picture is snippet from the .pdf previously posted. . . (possibly the picture is worth 1000 words?)

EFI Return.jpg