Fuel return line delete - opinions needed

[Milktruck]

Looking for thoughts on deleting fuel return line.

I'm running stock 2150 with electric fuel pump (4-6) psi.
Pump works like a champ. Used relay and cutoff switch. Charcoal canister is present and connected. I HAVE BEEN using the stock metal fuel filter with fuel return line (oriented correctly) with the return on top.

In the past three days I've had two instances where I jump into the Jeep, start her up and drive for a block and then it cuts out. Troubleshooting led to fuel supply in each case. Both times the engine was warm from prior use - but not HOT.

I began to suspect a plugged filter, but I can't see thru metal. I did verify that gas made it to the filter. So I replaced with a proper spec'd clear filter with no take off for fuel return. Plugged the return line. Fuel immediately pumped into the filter and remained 3/4 filled and clear. Jeep instantly fired up and runs better than it ever has.

This morning I hopped into the Jeep (after popping hood and observing fuel in plastic filter) and the beast fired up on a single crank. It NEVER does that. The standard start up procedure is: pump pedal 3-4 times - energize fuel pump with ignition switch - wait 5-6 seconds - crank 5 times - fire!

So I'm thinking that a delete of return would:
Give me quicker starts
Give me easy visibility into fuel supply (yes a fuel pressure gauge is a good idea)
Possibly alleviate a return line vapor lock issue?

I am not seeing flooding/overflow but am concerned. I have had repeated instances where it seemed that there was something blocking the fuel at the filter creating slow starts, no starts, or cut outs on run. Gas is clean as my old man eyes determine.

What is the collective group wisdom?

-thanks.

[REDONE]

If it works, then I say do it. However, I would keep the return line plumbing in place for a while, just in case a change in weather results in a change in operation and you want to go back. In the meantime, keep an eye on the charcoal canister to see if it gets soaked in gas.

[will e]

My Holley would run with the return line but vapor locked on long hot trips. I put on a fuel pressure gauge and saw I was getting just a couple of pounds. So I replaced my fuel filter with a non-return modle and that took it up to about 6 pounds. I never had the vapor lock issue again. I also run an electric pump.

I always suggest putting in a fuel pressure gauge. I put in an electric one with the sending unit right at the carb. Being able to monitor the fuel pressue from the cab is great.

[440sixpack]

You don't need one it's a waste of time . AMC cars ran the same fuel pump and none of them had a return line.

[WT91]

Fix it and keep it, your fuel pump will be happier.

[will e]

You don't need one it's a waste of time . AMC cars ran the same fuel pump and none of them had a return line.

The other school of thought is that by circulating the fuel it helps to keep it from vaporizing and causing vapor lock. Some people have luck with a return, others do not. I was better off without one.

[letank]

You don't need one it's a waste of time . AMC cars ran the same fuel pump and none of them had a return line.

in the 70's, 80's and 90's gas was formulated differently, I could drive in 90 degrees... dang even 120F in Arizona... stop the engine, never needed to pop the hood up... and restart without any issues... yes, mechanical fuel pump and carburetor... no problems, no vapor locking... and no return line...

Times are different, twitter, facebook and fuel injection are mandatory tortures

This is my message and I approve it...

[Milktruck]

With the plastic fuel filter and now fuel pressure gauge in place it has become obvious that I need to pull the fuel tank and have it cleaned. I think that running the fuel pickup lower has allowed me to pick up crap that was in the bottom of the tank that wasn't getting sucked up before. Dang it progress!

[az chip]

Fixing stuff exposes other problems. Don't hate the game.


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[will e]

Fixing stuff exposes other problems. Don't hate the game.

Signature worthy.

[Milktruck]

Updating this after some major work and miles.

I now believe that one should retain the return line.

This is my experience: I live in a pretty warm summer climate (NC) and I was suffering from vapor lock. As I traced the vapor lock issue and rectified it, I realized that I was having the issue in two places. First I would vapor lock near the carb - between the carb and the fuel filter, and second I would vapor lock on the run between the tank and the rubber line that ran up to the fuel filter. I noticed that if I kept the delete, the vaporized fuel/air would create a block between the fuel filter and the carb, and in fact it built some pressure. If I disconnected the line from filter to carb, on the back side of the filter, the pressure would release and spray fuel back out of the filter. (not good BTW) LEAVING THE RETURN LINE IN PLACE solved this pressure build up.

Then I was able to attack the other source of vapor lock by installing my fuel pump behind the fuel tank on the cross-member in front of the spare. I've driven almost 1500 miles without incident. Most days the temp has been 95 F.

My vote is that if your rig had a fuel return line - you should retain it.

Thank you for everyone who weighed in and helped me figure my way through the issue.

[Stuka]

I had to remove the return line when I switched to my weber and put a fuel pressure regulator/gauge on. You can't run a return line with a pressure regulator. Well unless you run two of them. But anyway, I have not had a single vapor lock issue since the change over. And thats in 100+ temps at 5k+ feet.

If you remove the return line, you HAVE to run a regulator, or you will over pressure the fuel inlet on the carb. Even my mechanical pump would hit 11psi at the carb without the regulator to drop it back down to 3 (Which is what weber calls for in my case).

[Milktruck]

Makes a lot of sense. For my application I am running a stock motorcraft carb with an electric fuel pump that runs pressure designed for a carb setup (4-6 psi).

Think I'm going to do a write up on what I did to fix the vapor lock. There is a ton of info on the list, but I had to grab it piece by piece and then second check.