Vapor Lock - 1971 Satellite 318 Looking to install a Fuel Vapor Separator, Need some Direction

[Plymouth71]

I have developed a recent issue with Vapor lock. It seems the local Government thought it would be a good Idea to mandate a minimum amount of Ethanol in local gasoline. Unfortunately we have been experiencing a number of very hot/humid days, and I keep stalling in traffic. I've watched a bunch of videos, and read a lot of threads on the subject. I've decided to try the Fuel Vapor separator fix first. I've bought a wix vapor separator fuel filter part # 33040.

I am just trying to determine the best place to locate it, and if I need to install a separate return line to the fuel tank.

 

[62 Dart Convertible]

Stock location just before carb for Wix filter is best. 1/4" nipple should be at 12 noon postion (as bubbles float) and yes, return line should go back to tank. Many modify their pickup/sender with an extra nipple, some add a nipple into filler neck.

Solved my vapour lock issues 100%.

 

[69hemibeep]

I run one on my jeep as close to the carb as I can get it. Are you sure the fuel pump is okay?

 

[Plymouth71]

Pretty sure the fuel pump is fine, it only happens on really hot and humid days when I get stuck in traffic, or if I'm sitting in a Drive-Thru I'm behind somebody else. Pretty sure the fuel is boiling and it's causing the problem. I guess there isn't a factory return line I could splice into on my 318.

 

[diesel_lv]

As stated above, closest to the carb. Reasoning is the further away from the carb, the more chance to get vapor again. Simplest return is in the filler neck.

 

[Cheapsunglasses]

Get your carb off the intake with one of these too.

Carburetor Heat Insulator #9265 Square Bore

 

[WileERobby]

I suspect you got another issue. How do you know it's vapor lock ? In any event, have you insulated the fuel lines going to the carb ? I have zero problems with my stock 318.

 

[beanhead]

Next time it stalls, jump out and see if any fuel squirts when you bump the linkage.

 

[Canadian1968]

Insulate the fuel line as suggested. I use "hot rod sleeve" from summit. Mine starts just as the fule line comes threw the frame under the fire wall and every inch is covered right up to when the fuel enters the carb.

 

[62 Dart Convertible]

Pretty sure the fuel pump is fine, it only happens on really hot and humid days when I get stuck in traffic, or if I'm sitting in a Drive-Thru I'm behind somebody else. Pretty sure the fuel is boiling and it's causing the problem. I guess there isn't a factory return line I could splice into on my 318.

My vapour lock issues were horrendous. I tried insulating fuel lines and carb insulators and they did jack, return line solved everything.

 

[BMosely]

Return line would be madatory. Understand also that that wix is not plug and play. You need an orifice restriction on the return leg. You can do it in the nipple or in the exit hose, but your fuel pressure will be too low without it. .060” if I remember correctly. I drilled a brass screw, turned it down, and press fit it into the nipple. Mine is a 440 so the fuel routed up along the distributor line. With heat being the issue, I divorced the fuel line from the block as much as possible. Fuel pump to fender, wix, then over the top to the carb with heat wrap on the line.

 

[Plymouth71]

This is what I am thinking of doing. Wish I didn't have to run a return line.

 

[62 Dart Convertible]

Understand also that that wix is not plug and play.

My Wix filter has a built in .060" orifice. You can see it looking into the return nipple.

 

[62 Dart Convertible]

This is what I am thinking of doing. Wish I didn't have to run a return line.

you will be thankful once you have

 

[sogtx]

Dam straight will be happy !
I use a 035 weld tip from mig for orifice

 

[1 Wild R/T]

What year is the car? If it's 71 or newer it'll have a vapor recovery system, If thats the case you can re-purpose the vapor line as a fuel return.... Actually I just noticed the year is in the title, 71.... Your choice whether you re-purpose the vapor line but it's been done may times...

 

[72RoadrunnerGTX]

Or leave the vapor recovery/fuel tank venting system alone and install a pre-bent reproduction return line, easy job. Can either get a sending unit with a return fitting or add one.

In this case, needed a 3/8" return, the 1/4" fitting wouldn't do for this Snipper install.

 

[Sweet5ltr]

Stock location just before carb for Wix filter is best. 1/4" nipple should be at 12 noon postion (as bubbles float) and yes, return line should go back to tank. Many modify their pickup/sender with an extra nipple, some add a nipple into filler neck.

Solved my vapour lock issues 100%.

This is exactly what to do in order to solve vapor lock. Even on my 470" low-deck, the fuel would start boiling, not in the bowls, but from the (new) mechanical fuel pump. That short time period in the fuel pump, caused vapor lock issues. I now run a carburetor heat shield, and a vapor return line (IIRC 3/8" fuel filter model from a 69'-70' Corvette - NOS) back to the fuel cell.

You would find it hard to believe, but I had the same issue with the 318 LA engine in our truck, you could see the fuel boiling in the filter during the first 100 - 200 miles (lots of vapor) and the engine wasn't even that warm. We've now driven that truck 6,000-miles, zero issues after the change. Pump-gas is trash. Even back in the day, the OE manufactures were designing systems to route the vapor back to the tank, a lot of the early-GM fuel pumps had vapor return lines.

 

[Sixpactogo]

I believe the fuel boils in the fuel pump itself from the heat radiated from the engine causing the vapor lock. Mopar fixed the problem on the Hemi and 440 cars with their separator unit mounted on one of the fuel pump bolts sending the excess fuel back to the tank via a 1/4" line. That WIX unit looks similar to the one Mopar supplied and is much cheaper but I heard it won't perform like the factory piece did. Not sure why but it probably has to do with regulation some how.

 

[1 Wild R/T]

I believe the fuel boils in the fuel pump itself from the heat radiated from the engine causing the vapor lock. Mopar fixed the problem on the Hemi and 440 cars with their separator unit mounted on one of the fuel pump bolts sending the excess fuel back to the tank via a 1/4" line. That WIX unit looks similar to the one Mopar supplied and is much cheaper but I heard it won't perform like the factory piece did. Not sure why but it probably has to do with regulation some how.

Actually the Wix works fine at doing exactly that, it's the older reproduction vapor separators that had a problem... The return line didn't have an orifice so most of the fuel went straight back to the tank... Fuel pressure of about 2psi doesn't make a 440-6 or a Hemi very happy...