19g fuel tank swap w/fuel return line for efi.

I’ve got a 73 maverick my son and I are building for his first car. The car sat for many years without a motor. We’ve come to the part where the fuel system is to be dealt with. I ordered a 19g tank, straps and sending unit from AutoKrafters. The tank bolts in without any major fitment problems, including around the rear valence.

The question is, the evap fitting is different from the 15g tank vs. the 19g tank. Is there a clean way make the small push in type evap hole in my 19g tank a fuel return for an aftermarket FiTech or Holley efi system? The steel evap lines from under hood back to the tank would be great to use for this purpose also, as they’re already routed and look factory.

 

Here’s the 15g tank with the evap provision installed. Notice the nasty rust and goo inside the tank. Not good for efi.

 

When you remove the evap fitting, the bottom side looks like this. There’s a tiny hole inside the barbed end that could easily be drilled out to make for a fuel return. Problem is, the 19g tank doesn’t have this style fitting. The 19g has a more modern, push-in type fitting, presumably made of plastic.

 

Hit 71 Gold on the forum, I believe he has a 19 gal swap on his car. Frank has done just about all a person can do to one of these cars in the realm of modifications.

 

I believe Frank (71Gold) is running the Holley 12-305, and I don’t think it has a return.
https://www.summitracing.com/parts/hly-12-305

I’m thinking the Hyperfuel 40015 as it has provisions for a return.
https://hyperfuelsystems.com/products/40015/

 

I didn’t notice that on the FiTech site, but that’s probably going to work. Thanks for the link.

 

I believe he’s had FiTech b4 Holly setup

 

self return
Holley 12-305
"No return line needed (all return fuel is handled inside the tank)"
67 GPH/255 LPH @ 58 PSI

 

Return or Returnless: Which Fuel System is Right for You?
https://www.onallcylinders.com/2017/10/10/return-returnless-fuel-system-right-video/

 

interesting reading but....that was just one style return.
the...Holley 12-305
returnless... returns the fuel at the fuel pump pickup in the tank. that way only the regulated amount of fuel goes to the motor (EFI). it maintains a set 58 PSI. my ECU runs the pump to pressure then shuts off when only the switch is on and not in the start position. this way the pump only runs a few seconds if for any reason there is a no start situation or engine dies after starting.
also some systems require the regulator to be before/after the fuel rails.
I have a friend that switched his key on troubleshooting a problem and it got left on and hydrolocked the engine with fuel...

my system...returnless w/vacuum regulator
I did this so the regulator would drop the fuel pressure 5-6 PSI at low vac, conditions... idle/cruise.

suggestion...
don't buy a cheap regulator.

 

That means an injector was being held open, would run really rich. Was that the problem he was troubleshooting?
My GF's Nissan 300ZX had a stuck injector and hydrolocked. Shoulda seen all of the fuel that came out when I drained the oil pan.

 

I’m totally cool with running a return system over the internally bypassed Holley referenced above. I can see the fuel heating deal being a problem with low fuel in the tank, remember the car is for a teenager. There won’t be a lot of his own money to fill the tank.

I’m likely going to run the FiTech fuel command or the Edelbrock sump mounted between the passenger shock tower and the firewall. Both of these still require a return, but are fed by the mechanical pump on the timing cover.

 

That's what I have. Ran a 3/8" aluminum line back to the fuel filler neck for the vent.

 

I've read this several times in different media...if this were a problem then all tank pumps would be laying on their sides in the tank, not standing up sometimes 8-10 inches needing a half tank of fuel just to cool the pump.
I personally don't see it. the same pump is used for the rail mounted pumps. my take on it is the fuel going through the pump is what cools it, if not the rail mounted ones would burn up with a full tank of gas...
the sump in the tank is for...keeping gas to the pickup not to submerge the pump to keep it cool.

JMO

 

I’m talking about keeping the gasoline cool. The pumps can totally hang with heat. If the fuel is low, there’s minimal gas to take away the heat, so it builds up in the gas.