Fuel tank and EFI

Modified FSJ Tech Area
Post Reply

Topic author
SkylinePCG
Posts: 72
Joined: Tue Apr 16, 2013 11:28 am

Fuel tank and EFI

Post by SkylinePCG »

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

Thanks!

sonoraed
Vendor
Posts: 674
Joined: Sun Apr 07, 2013 7:38 am
Location: Sonora,Ca
Contact:

Re: Fuel tank and EFI

Post by sonoraed »

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.
Cheers

ALASKAFSJ
Posts: 1
Joined: Thu Nov 03, 2016 10:55 pm

Re: Fuel tank and EFI

Post by ALASKAFSJ »

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.

sonoraed
Vendor
Posts: 674
Joined: Sun Apr 07, 2013 7:38 am
Location: Sonora,Ca
Contact:

Re: Fuel tank and EFI

Post by sonoraed »

ALASKAFSJ wrote: 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.
Yikes I just saw this post still want pic's ?
the tank in my 79 J10 is from a 2000ish suburban mounted where the spare tire would be, uses the oem fuel module with sender which I like a lot,anti slosh, can be cut down for height,fittings are oem snap on,works well with oem early 2000 checy pickup fuel filter/pressure reg/fuel return.

ArchitectJS
Posts: 293
Joined: Thu Oct 15, 2015 5:01 pm

Re: Fuel tank and EFI

Post by ArchitectJS »

The garbage bag; you're being hyperbolic, right? I like the rubber liner. I assume its there to relieve pressure / abrasion between skid cover and poly tank. I cleaned it all and put it all back the way it was.

I ran both supply and return thru the original / OEM sender. Checked fit. Then, notched the retaining nut so that my new lines could run across / thru it- up against the underside of the body. Works for me...

I ran the pump on the passenger rail. Instructions say low, right? Cross member didn't make sense to me- but what do i know...
1982 Cherokee, base (Bumppo)
AMC 258 / A727 - AMC 20 / NP208
Holley Sniper with Hyperspark
3" Rough County Lift
Post Reply