starving for fuel

[Dillon79scotts]

Ive got a 79 chevy 4x4 that i use for offroading, and i swapped a 5.3l lm7 with a walbro 255 for my fuel delivery on the frame rail.

Well what the problem im running into is when i back onto a hill (half a tank and its 17 gal tank) then the pump starts screaming at me, because the fuel sloshed to the front and its not reaching the pickup.

Besides keeping the tank near full at all times off roading, does anyone have any further ideas?
Im not sure what to do here to extend the pickup, or what because it would work vise versa if i pulled straight onto a hill it would slosh to the other side.

Idk if anyone else has ran into this problem, but any input here would be great.

[Dillon79scotts]

i guess i could run a baffled fuel tank, but only problem is now what years are compatible.

i know the chevy trucks come with baffles in them,

but what tank would be able to mount in the same spot on a 79 chevy 1/2 4x4 with a 17 gal tank

[vin63]

Yes, baffling will help, but I am not sure about cross referencing OE tanks. Be careful because the electric fuel pumps do not like to run dry for even short periods. I tend to approach this as a drag racer, but the inertial properties are very similar in your application (extreme fluid movement in the fuel cell/tank). I have modified stock tanks with baffles and sumps, but would lean more toward an aftermarket tank with baffling, etc. for that type of extreme offloading.

[Clyde65]

I would think...A). keep more fuel in the tank...B). do a sump, or put the tank in the bed and draw from under the tank ( same as a sump)

[Dillon79scotts]

well i know the newer chevy trucks have a baffle built into there tanks, so im wondering if this would be okay?

[BR3W CITY]

Fuel cell foam will work in place of a baffle. Helps keep fuel in place and my tank never ever sloshes, not even with how loose my rear setup is.

[Dillon79scotts]

Originally Posted by BR3W CITY

Fuel cell foam will work in place of a baffle. Helps keep fuel in place and my tank never ever sloshes, not even with how loose my rear setup is.

so one on each side of my pickup for the tank then? need to get dimensions so i can order some and give this a shot.

[BR3W CITY]

I have a sump point in the rear-center of my tank, so there is square of foam that sort of straddles the sump. I think mine is about 10x12x4 or something like that.

[Dillon79scotts]

Originally Posted by BR3W CITY

I have a sump point in the rear-center of my tank, so there is square of foam that sort of straddles the sump. I think mine is about 10x12x4 or something like that.

couple people i have asked and talked to dont think this foam will work for the offroading application for me?

[foamypirate]

Just order a tank and sending unit for an 87' truck with TBI. They have baffles since they were fuel injected, and are exactly the same as far as outside dimensions. BTW, you have a 16 gallon tank, not 17. RockAuto carries several different brands of aftermarket tanks for around $100. The fuel injected sending unit runs about $100 as well. You should be able to use the Walbro in tank just fine with that unit.

The aftermarket tank likely won't have the same style of baffles as the factory tank, but it will work just fine. For reference, here is a factory 87' 16 gallon tank with baffles (from my truck):

[BR3W CITY]

Originally Posted by Dillon79scotts

couple people i have asked and talked to dont think this foam will work for the offroading application for me?

I guess it depends; I'm trying to think of why it wouldn't work.
Dillon, is it an in tank 255? Or where are you drawing from?

[Dillon79scotts]

Originally Posted by BR3W CITY

I guess it depends; I'm trying to think of why it wouldn't work.
Dillon, is it an in tank 255? Or where are you drawing from?

im running the external universal fuel pump. mounted as close as i can to the tank. on my frame rail.

Yeah i think im going to start with dropping my tank, checking out the pickup tube to make sure its not cracked because that could help cause the issue. and then move onto a baffled tank.

[Dillon79scotts]

anyone know of a year truck tank that will fit in factory spot and is baffled

[foamypirate]

Originally Posted by Dillon79scotts

anyone know of a year truck tank that will fit in factory spot and is baffled

Did you even read my post? I gave you all the information you needed.

[Dillon79scotts]

Oh shoot. Okay I saw that and totally spaced out. Do the tbi fuel pumps run high enough pressure?
Posted via Mobile Device

[foamypirate]

Originally Posted by Dillon79scotts

Oh shoot. Okay I saw that and totally spaced out. Do the tbi fuel pumps run high enough pressure?
Posted via Mobile Device

No worries! I just re-read my most recent post, and I kind of sounded like a jerk, sorry about that!

You'll need a pump from a newer truck if you aren't able to use your walbro in-tank. The TBI pumps only put out around 20psi max (regulated to around 13 at the fuel rail) which is way too low for any LS motor. LSx's typically need around 58-60psi at the rail. ACDelco EP-381 will do the trick and is a perfect fit with the 87' sender.

[Dillon79scotts]

Originally Posted by foamypirate

No worries! I just re-read my most recent post, and I kind of sounded like a jerk, sorry about that!

You'll need a pump from a newer truck if you aren't able to use your walbro in-tank. The TBI pumps only put out around 20psi max (regulated to around 13 at the fuel rail) which is way too low for any LS motor. LSx's typically need around 58-60psi at the rail. ACDelco EP-381 will do the trick and is a perfect fit with the 87' sender.

Well I've got my 79 chevy sender still. I have a external walbro pump I run. But will my old sender work? Picked a tank and everything up for 50$ from local auto wrecking
Posted via Mobile Device

[foamypirate]

Originally Posted by Dillon79scotts

Well I've got my 79 chevy sender still. I have a external walbro pump I run. But will my old sender work? Picked a tank and everything up for 50$ from local auto wrecking
Posted via Mobile Device

You'll need the fuel injected sender, as it has provisions for an electric fuel pump. You can find one from pretty much any 87-91 squarebody truck. Make sure it's from the same side as the tank you got. Other than that, you'll just need an in-tank pump. The ACDelco EP381 I mentioned earlier is a direct fit to the 87-91 sender both physically and electrically (plugs are the same as the TBI fuel pumps).

[Dillon79scotts]

Originally Posted by foamypirate

You'll need the fuel injected sender, as it has provisions for an electric fuel pump. You can find one from pretty much any 87-91 squarebody truck. Make sure it's from the same side as the tank you got. Other than that, you'll just need an in-tank pump. The ACDelco EP381 I mentioned earlier is a direct fit to the 87-91 sender both physically and electrically (plugs are the same as the TBI fuel pumps).

i just took out the pump. and put my pickup tube there.

i got a tank today (87 tbi chevy) its a 16 gallon supposly but seems alot smaller than the 16 that was under my truck.

one thing im running into is the fuel inlets are different size, problem fixed there.
anther thing is between the two tanks since there different lengths, the mounting brackets are placed in different spots on the tanks. so i have to move it down further on the tank and hope this works.

if anyone has any ideas, or has done this before and input is appreciated. Doesnt hurt

[raic65]

If the baffled tank doesn't work out, try giving this a shot

http://www.vaporworx.com/

I kinda copied the idea and built my own tank using the pump out of a 07 silverado when I did my LSX swap

[foamypirate]

Originally Posted by Dillon79scotts

i just took out the pump. and put my pickup tube there.

i got a tank today (87 tbi chevy) its a 16 gallon supposly but seems alot smaller than the 16 that was under my truck.

one thing im running into is the fuel inlets are different size, problem fixed there.
anther thing is between the two tanks since there different lengths, the mounting brackets are placed in different spots on the tanks. so i have to move it down further on the tank and hope this works.

if anyone has any ideas, or has done this before and input is appreciated. Doesnt hurt

Is your truck a longbed or short? Sounds like you may have actually had a 20 gallon tank, you have a longbed (though my longbed came with 16s). But as far as I know, they both strap at the same location. I suppose it's not out of the realm of possibility that the non-efi tanks have straps in a different location. Can you post up some pics of both tanks?

[Dillon79scotts]

my truck is a long bed. 16 gal tanks, went from mid cab, to about mid bed.

this efi tank is about 2/3 the length of the original tank.
mounting brackets were in different spots which made my filler tube to short to. got it all worked out today.

Ive got pictures also

[Dillon79scotts]

im thinking i got a 10 gal tank or something from the wrecking yard. but idk yet i guess until i fill it up. i used the sending unit that came in the efi tank, and just removed the pump and put my pickup tube there.

Will this sending unit read right? on my gauge

[foamypirate]

Originally Posted by Dillon79scotts

im thinking i got a 10 gal tank or something from the wrecking yard. but idk yet i guess until i fill it up. i used the sending unit that came in the efi tank, and just removed the pump and put my pickup tube there.

Will this sending unit read right? on my gauge

I'm thinking it should, pretty sure all 73-87 were 0-95 ohms, but don't quote me on that. My EFI 16-gallon tank is the same size as what you got. Maybe your old tank was a 20 but full of so much crap it only held 16 gallons, lol.

[Dillon79scotts]

Originally Posted by foamypirate

I'm thinking it should, pretty sure all 73-87 were 0-95 ohms, but don't quote me on that. My EFI 16-gallon tank is the same size as what you got. Maybe your old tank was a 20 but full of so much crap it only held 16 gallons, lol.

had a dent on the bottom.
but it was very clean it amazed me. selling the tank.

oka well with 5 gallons of fuel in that efi tank its reading a half? lol