Fuel tank and EFI

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Fuel tank and EFI

Post by SkylinePCG » Tue Nov 10, 2020 9:22 pm

In the middle of going TBI, and with everything under the hood wired, fuel lines are next.

I dropped the stock tank because... it’s 40 years old...
It’s poly. It’s vented. It was wrapped in a garbage bag.

My questions are: that garbage bag; is it necessary? And if it is, is there a better alternative?

The stock sending unit has 5/16 and 1/4 inch ports for feed and return. I’m going with new 3/8 feed and 5/16 return lines. Are otherwise-compatible sending units available with these different port sizes?

I’m going to try and use the crossmember above the rear axle to mount the fuel pump. Anyone have issues or insight with this? Or with running the fuel lines up the passenger side frame?

Is it important to keep the tank vents? Would a vented gas cap provide the same functionality? I


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Re: Fuel tank and EFI

Post by sonoraed » Thu Nov 19, 2020 7:27 am

Been a while but I installed TBI from a 92 chev p/u on my 79 J10 amc 360 in 1999, best thing ever done to that motor, used the oem fuel lines because there was a factory return line,stock tank was metal on mine but if your poly is not cracked probably ok, TBI's don't need much fuel pressure (12-15 psi) frame mounted pump worked very well, because most pumps are pushers should be mounted near the tank outlet,tank vent is very important pump would have a hard time pulling fuel from a negative pressure source,there were two tubes into my tank from gas cap, large line for filling tank, small line for venting,while tank is out would replace sending unit.
On the other hand if a LS engine or aftermarket fuel injection system is in the cards, they generally require 58 lbs psi and a intank pump is the only way to go,currently have a LM7 (gen III LS type of engine) in my truck and use 2000 ish GM fuel module in tank with GM fuel filter/pressure regulator works
very well.

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Re: Fuel tank and EFI

Post by ALASKAFSJ » Thu Nov 19, 2020 2:32 pm

Sonoraed, any chance you have or could get some pictures of your "in tank setup"? Looking at options for my J10. We just finished installing a Sniper TBI in my Brothers Wagoneer with a frame mount pump, love the sniper upgrade but the external pump is pretty loud. I would rather have my pump in the tank when I set mine up.

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