Plumbing for Fuel Pressure Regulator

[Boaf 32]

Fellow LCer's


I have searched and viewed a few different ways to plumb a fuel pressure regulator for my 72 LC with a Weber Carb. I understand the pressure should be around 3 PSI.

The attached shows an inlet to the regulator (with the hose clamp) and and outlet and Vaccuum. My question is:

1. does the outlet go to the fuel return (before the fuel filter or into the tank)? Or
2. does it go to the carburetor itself.

What I have seen is the input to the fuel regulator has a T in the fuel line. One line goes to the Carb, the other to the regulator. Then the second outlet of the fuel regulator would go to the fuel return (tank or Line).

I have also read that the second “outlet” line goes to the Carb.

Naturally there are no directions or support line for this regulator (Get what you pay for I guess).

Any help is appreciated.

Boaf

 

[Weber Sarge]

Don't waste your time with a regulator, if the fuel pump is rated below 5 or so psi , just use an older Jeep CJ fuel filter. Those filters have a built-in bypass port that will route off the excess pressure back via the return line. Main input line is 1/4", output to return is 3/16" so you'll have to use a fuel-safe adapter or just stretch the hose to hook it to the stock return line on the truck. For the factory LC mechanical fuel pump it should work just fine as well.

Sarge

 

[screw aerodynamics]

I was perusing posts to get some insight as to my cold start issues on my Weber 38 DGES (synchronous) on my F-Motor FJ-40--1969 motor. Ventilation is good.
I was looking for a basic set up for the F-Motor with that Weber. Maybe something is not set right, which may be causing the hard cold start. Another issue is that I installed an after-market polyethylene gas tank which has the pick up tube on top of the tank (my old tank had it down at the lower side.) I wonder if the stock mechanical fuel pump will draw up the fuel the right amount? If not, I may need an electric fuel pump. I heard that the fuel pressure may need to be adjusted (down?) IF I use an electric fuel pump. That's when I saw your post about the fuel pressure regulator. Interesting. Are you installing that to achieve or fine tune to get 3psi? Also, where do you think the best place would be to install a fuel pressure gage? The gage is just a gadget thing (probably not really necessary.) Doesn't the Weber
have an extra threaded part (right where the carb. filter is) to place a gage? Thanks, you have good posts and I'll follow you.

 

[screw aerodynamics]

Just to clarify: the cold starts have been going on for years (I've just been using starting fluid spray for the occasional runs and Sunday trips.)
The new gas tank is something new (in addition) so the carb issue has come up. Also, since I'm doing maintenance, I wonder if there's something better I can adjust with the carb. BTW, I will test the output of the mechanical fuel pump with this new tank once I get it running (it should be ok,) I may just go ahead and install an electric fuel pump (since I do have one laying around here,) if nothing else as a boost to get gas in the bowl on those occasional rides. So there's really two issues I was wondering about: 1) the old issue of cold starts and 2) wondering if the mech. fuel pump will pull up from this new tank (I understand mechanical fuel pumps are good pulling mechanisms whereas electric fuel pumps push fuel from tank to carb. Thanks for any feedback.

 

[Boaf 32]

Thaks "SA" I need to check my pressure on my fuel line. I believe it is way above 3 PSI. Will keep you posted when / if it's installed, if I can figure out how to get a return line to the tank. Maybe like Weber Sarge says, use an old Jeep Filter. But as below, I need a return line to my tank.

Interesting about the tank. My original had holes that could not be welded. The tank I brough from SOR was different, no returns or filter holes for pressure relief. I called them back and they said that is what it called for. I should have argued, I know it is not right.

Boaf

 

[brian]

I ran weber's for years with oe mechanical pumps, never felt a need for fuel pressure regulator.

 

[MBest75]

I had an in-line fuel
Pressure gauge laying around and used it in this configuration bc I was running too rich and wanted to check it. Baseline is I needed smaller jets (humidity I guess) but it showed a solid 3 psi with the stock mechanical pump. So I’d be surprised if you need a regulator with a stock mechanical pump.


Also there’s really no fuel return with a Weber so you don’t need that line connected. Unless of course you want to run the CJ filter (which I’m planning on doing eventually).

If you want to just check your pressure buy an in line gauge.

 

[Rusty 72]

If your tank needs a return line here are a couple ways to do it. First is drill hole in top of tank then install this fitting.

Another way is to drill hole in filler neck and braze a piece of tubing in it. Inside the filler neck I run the tubing a few inches toward the tank. I have used this method with no problems.

 

[thebigredrocker]

How long are you having to crank your rig over til she gets primed with fuel?

Is your choke working? Mechanical or electric?

Does this problem result in you draining your battery? If so, you might try a gear reduction starter.

 

[Boaf 32]

If your tank needs a return line here are a couple ways to do it. First is drill hole in top of tank then install this fitting.

View attachment 1734369

Another way is to drill hole in filler neck and braze a piece of tubing in it. Inside the filler neck I run the tubing a few inches toward the tank. I have used this method with no problems.

Thanks Rusty. I thought that would be an option to put the return in the filler next.

 

[screw aerodynamics]

Thaks "SA" I need to check my pressure on my fuel line. I believe it is way above 3 PSI. Will keep you posted when / if it's installed, if I can figure out how to get a return line to the tank. Maybe like Weber Sarge says, use an old Jeep Filter. But as below, I need a return line to my tank.

Interesting about the tank. My original had holes that could not be welded. The tank I brough from SOR was different, no returns or filter holes for pressure relief. I called them back and they said that is what it called for. I should have argued, I know it is not right.

Boaf

Hey, B. 32, here are a few link for a decent gas tank. The pick up tube draws up from top though which I wonder if my mechanical fuel pump will draw up enough to have good fuel pressure. I used a Moeller Fuel gage with the supplied float arm, but if you want the right sending unit you may want to check out the one from E-Bay.
I had to bend the arm for my Moeller float arm to fit in properly and the gage does not read accurate, but close enough for me. FYI, I read that if you use that special 3-way Jeep filter that it should be locate at the highest point, or at least above carb. to prevent vapor-locking (see snap-shot by another helpful poster.)
Early to 1978 Toyota Land Cruiser FJ-40 Fuel tank [6040] - $199.94 : CruiserParts.net, Toyota Landcruiser Parts
MTS Plastic Gas Tank for 1973-1978 Toyota Land Cruiser FJ-40
FJ40 FJ45 Landcruiser Fuel Gas Tank FREE SENDING UNIT | eBay