I apologize if this has been covered numerous times. I have posted much and would like some help. Its time for another fuel pump. Heres what im trying to do. I need a draw straw, walbro and the rest. My question is on the return lines and the breather. Is there a return line from the regulator to the tank and also one from my vp44 to the tank or do these get connected? the picture right I forgot the stock fuel filter in the picture.

 

I do not have a sketch but I will try to describe what I did.

From the tank I cut the metal line and used 3/8" hose.
To Napa 3033 20 micron fuel filter
To Walbro 392
To Simflo regulator - return line to filler neck vent
After regulator fuel line goes to 1/2" all the way to the stock fuel filter. I already had a "big line kit" on the truck.

I got the simflo from Vulcan Performance and they will put whatever size fittings you need on the regulator when you order it.

If this is unclear I can snap some photos. Hope this helps. Oh by the way, I see about 19 psi at idle and 15 at WOT. I'm very happy with the results and price.

Brad

 

Yes, there should be a return line from the regulator, or from before the regulator, to the fuel tank. There is no way to use a non-bypass regulator with a Walbro unless you use active pump control, like a PWM a la what Bent_Valves did on his. You can view an example of plumbing a Walbro in the link in my signature.

 

My question was more concerning the vp 44 return. With the draw straw 1 it has 2 ports so I didnt think you needed a return to the filler neck, I assume it goes to the other port on the draw straw. I was mainly trying to figure out if the vp44 return tee's into the return from the regulator, or do you need 2 return lines to the tank? 1 for the vp44 and one for the regulator? Bent valves setup is nice but I couldnt build a PWM circuit myself. I dont think he is selling them eighter. I really enjoyed your write up also.

 

The VP44 return IS the return line. There is a supply line (fuel tank to fuel filter to VP44) and there is a return line (VP-44 to fuel tank). You do not need a return line to the filler neck unless you think you will be spilling enough fuel to need one. Your setup should be: Fuel line to fuel screen to Walbro to swagelok (up to return line) to fuel filter to VP44. Your swagelok IS the regulator when you set it to the fuel pressure you want. I don't think you want a regulator AND a swagelok as they will be hard to get adjusted right. A regulator will have its own return line and have to be plumbed into the OEM return line. The swagelok in like manner is plumbed into the OEM return line but I don't think you can do both without having a lot of problems....

 

In my opinion you do need another return line, second one, from the regulator to the fuel tank. The VP-44 return line is too small to handle the Walbro overflow, which is many GPM. I made a second return line because I did not want to block up the VP-44 return line and cause decreased cooling flow through VP-44. If you tee into the stock return, you are essentially pressurizing the exhaust line of the VP-44, and increasing its internal pressure since your 14 psi check valve now will be operating at 14 psig over the pressure created by Walbro overflow, which I would say would be some 10-20 psi by itself with the 6 foot long 5/16 steel line for a drain.

 

I agree you do need a separate return line with the walbro pump it moves a lot of fuel and can produce a LOT more pressure than the stock carter,airtex, holley blue, ect, type of pumps .It is a positive displacement gear rotor pump.
I plumbed mine into the filler tube for my fuel tank very easy to do - cut it put in a tee and a barbed fitting slip on the line and clamp it.

 

I plumbed mine into the unused auxiliary tube that is normally capped off on the tank cap of our trucks. Zero mods needed.