Fuel System. In tank or external? Baffling etc..

[Vandals909]

I'm at the stage in my build where I need to start putting together my fuel system. I have a 71 shortbed that i'm putting a 2006 Lq4 into.

I would like to relocate the fuel tank to the rear of the truck. Looking at options. Is it better to have an external or internal fuel pump?

My main concern with an inline pump such as a Bosch 044 is it starving due to baffling/not being able to mount it low enough for gravity to help feed it if the tank is less than 1/2 full. I do like the idea of having a pre filter and after filter on an external in line pump.

As for an internal pump, not sure how reliable they are and if they eliminate concerns for them starving for fuel.

Not sure which tank is the best option for internal and which tank is the best option for external.

I do not want a tank that is to low in the rear.

From experience what are the pros and cons to each setup?

Thanks in advance.

[ls1nova71]

All the OEM's put the pump in the tank, so that should say something... Only real down side to them is you usually have to pull the tank to change it, but that said, they last longer since they are cooled by the fuel and they are only pushing fuel and not pulling it which is harder on a pump.

[Vandals909]

From experience anyone like a tank and particular pump setup?

[Matt Cramer]

I've stuffed a Walbro GSS392 into my stock tank. Fit right through the sending unit hole. It's worth noting that an in tank pump on a tank not designed for one can still have fuel starvation issues while cornering.

I kept my in-cab fuel tank, but wouldn't do that if I did a swap all over again. Still has fuel fumes in the cab from time to time.

[compsystems]

I used a 1990 jeep wrangler gas tank and made brackets to mount under the bed. The tank is internally baffled. I used an 87 blazer sending unit and walbro 255 fuel pump. I modified the tank inlet location a bit for my setup.

It was a bit of custom work for brackets and tank inlet location but it fits well and is not seen below the bumper.

[slotard]

compsystems, what did it take to make the sending unit and pump fit? How big is the tank?

[compsystems]

the tank is 15 gallons. Its a little small but its the best option the tucks up into the frame. I used angle iron to make a square bracket the fit the space between the frame opening and tank.

The walbro is a bolt in install into the 87 blazer sending unit, no modification required. The sending unit is a drop in fit into the jeep tank with O-ring and lock nut. You will only need to get adapters to fit the metric thread of the sending unit to your fuel hose fittings of choice.

I went with -8 AN line feed and -6 AN line return.

Gas tank = $65
Blazer sending unit =$65
Walbro pump = $130

You will have to modify the tank for your fill location.
Bed fill \ fender fill\ ect...

[Andy4639]

In tank pump built for fuel injection is the best way to go.

[crakarjax]

Originally Posted by compsystems

the tank is 15 gallons. Its a little small but its the best option the tucks up into the frame. I used angle iron to make a square bracket the fit the space between the frame opening and tank.

The walbro is a bolt in install into the 87 blazer sending unit, no modification required. The sending unit is a drop in fit into the jeep tank with O-ring and lock nut. You will only need to get adapters to fit the metric thread of the sending unit to your fuel hose fittings of choice.

I went with -8 AN line feed and -6 AN line return.

Gas tank = $65
Blazer sending unit =$65
Walbro pump = $130

You will have to modify the tank for your fill location.
Bed fill \ fender fill\ ect...

Is this the sending unit you used? Amazon.com: Spectra Premium FG12L Sending Unit...
And it looks like the tank's filler might clear the frame rail for a side fill... true?

[Vandals909]

I hope some more people chime in on there tank and pump setups and if they have any issues with it? Starvation and irregular fuel tank level readings.

[Hart_Rod]

In tank and baffled.

[Vandals909]

What brand tanks and fuel pumps?

[BR3W CITY]

External, sumped, no baffles (tank foam). 16 gal cel.

Overall, has been solid for like 4 years at least. Haven't killed a pump yet, I drive ~42lb injectors, so its put some work in.

Only problem is tank foam was actually from pre-swap and is starting to get a little old. On extremely hard stopping when ~1/4 tank or less, it'll starve a little (like going 75-0 on a really short off ramp). Not always, and not usually all the way, but you see it in a log. I'm looking at switching to using a Fuel-mat, but haven't commited yet.

[Vandals909]

Looking at the BOYD welding tank and the ece efi tank. Anyone have any pros and cons to either? Besides price? Anyone driven around with either tank? Any issues full or 1/4 tank. These tank are expensive.

[Hart_Rod]

Originally Posted by Vandals909

Looking at the BOYD welding tank and the ece efi tank. Anyone have any pros and cons to either? Besides price? Anyone driven around with either tank? Any issues full or 1/4 tank. These tank are expensive.

I have used both and both are quality products. I have had no issues with 1/4 tank driving.

[Custom 68]

I am using one of Boyds first tanks with the EFI in-tank fuel pump.
I say it is one of the first because I believe he has since improved his baffling. Currently I need to work on this for my truck. It doesn't work as well as I think it could as it is. I am not bad mouthing this as it fits great and looks great. Most of the time I have no issues however under hard acceleration and under half a tank it gives me problems.
I am going to contact him and see if there are any suggestions.
I have seen the fuel mat Brew mentions and that may be a direction but I am unsure what baffling is in the tank now.

[Custom 68]

And to add to this prior to this tank I had a poly blazer tank mounted in back with an external pump. First it didn't look very good as it hung down quite a bit and I did have a pump go out on me. I had been on the power tour and was returning home so it had been stressed quite a bit with the heat. My trip home was 15 or so hours of straight driving and about 10 hours into it i started fighting it. I had to make several stops the rest of the trip for cool down but I did drive it home with no real problems. I swapped the pump until I could afford a nice tank.
Like others have said I think the in-tank pump is the best way to go It keeps cooler.
I have had this swap in for 11 or 12 years so either will work.

[Vandals909]

Thank you for the replies guys. I just want to make sure if I drop $700+ on a tank and pump setup that it has 0 issues. I think that's a reasonable expectation

[mongocanfly]

I'm running stock tank,, no baffle or foam,, walbro 255 external, vette filter/reg..I've run my tank level down very low and never had any starvation issues..I may have just got lucky though..in tank is probably best..as already stated the factory setups are that way.

[indymachinist]

A Bosch 044 can and regularly is used as an in-tank pump. For an average LS motor it is overkill though.

[BR3W CITY]

Originally Posted by mongocanfly

never had any starvation issues..I may have just got lucky though.

So many factors to ever know for sure. My cell is mounted center and VERY low, but I also have an extremely loose suspension compared to guys on stiff springs and low pro rims. My truck transfers a lot of weight front to rear, and I probably change the height of my cell more drastically than most guys. I can probably lift my rear end 6" if I locked up the front brakes (need to limit that in the new suspension).

Originally Posted by indymachinist

A Bosch 044 can and regularly is used as an in-tank pump. For an average LS motor it is overkill though.

Too Much = never enough.

[Andy4639]

Mine is a 42 gallon Suburban tank inside the bed under my fiberglass cover. it sit's right behind the cab and it was for a TBI fuel injection pump to start with. All I did was swap the pump out for the TPI motor and now for the LS motor.
You can use the foam but as stated it will start coming a part later on. The best solution is a tank made for this app.
I can't see anything wrong with the Aluminum tank as far as normal use. The steal will be a bit more stronger maybe.
The thing I don't like about aluminum is the threads are bad to strip and on SS they are bad to galling.

[Vandals909]

Does anyone have any experience with aluminum cracking or ripping? Trying to see if stainless is really worth the extra cost. Truck will be driven maybe 3 or 4 times a month a short distance

[BR3W CITY]

For a smaller cell, aluminum is nice just from a weight perspective. I don't mind the poly cells, but they don't usually take the "best" advantage of the room available, and you can't put your fittings at will.

Anyone know what those big 100 gallon bed-mounted extended range tanks the diesel guys use are made of? I have no idea.

[mongocanfly]

Brew if your talking about those in the bed diesel tanks.. a buddy of mine has 2 in 2 different trucks ,one is a stand alone tank and its made of 1/8" steel ..the other is a toolbox/tank combo and its all aluminum.