vapor locking

[green77]

I am having problems with my 77 vapor locking. I am running the stock tank, and factory 2bl carb. I replaced the fuel line with a rubber line when i restored it. I've changed gas caps, left the cap loose, nothing seems to work. It seems to be worse when it gets below a half tank. I can pull the fuel line off at the carb, crank it a few times and that will solve it for a while. Any suggestions will be appreciated. thanks.

 

[ps4wdc]

Make sure that the fuel line you ran is no where near the exhaust manifold, if the line is close in some spots cut another hose in half and wrap it around your fuel line in those spots...your problem is probably heat in this area.

 

[Jeep Slayer]

: ?:? :
Got no idea but keep us up to date

 

[Waverous]

I HAD a vapor locking problem, but no more! I too suffered from continual vapor locking in my 73. No matterwhat I did, I could not correct the problem. I tried new carbs, lines, mainifolds, cheap inline electric fuel pumps, return lines, and new tanks. The problem is Ford routes their small metal fuel line around and across the hottest part of the engine - between the hot air from the radiator and the heat from and engine.
I completely rerouted my fuel lines. First I purchased a decent rotary fuel pump from Mallory (120gph at 7psi) mainly to have a quiet electrical pump. I mounted it on the passenger side of the Bronco so that I could run the fuel line from the selector switch and across the transfer case crossmember. From there, I ran the fuel line up the frame and into the back of the carb - completely avoiding the front of the engine and the mechanical fuel pump.
As irony would have it, the day I did this conversion was on of the hottest days of the summer. I sat on I-70 in the middle of traffic for 1 hour in 103 degree heat while an accident was cleared off the highway. My bronco didn't spuutered the entire time

 

[green77]

thanks for the info. I tried to route my fuel line as far away from the header as possible but suspected it wasn't far enough. i had also given thought to an electric pump but just havn't done anything yet.
thanks again.

 

[74bronc]

Wrap the fuel line in that reflective insulation in the spots where you think the line is being attacked by heat. You can get it at www.summitracing.com for a reasonable price.

 

[Rustytruck]

I had a long time intermittant bout with vapor locking which wasn't solved until I changed to a quadrajet carb. but I did learn alot in the process. Check under the carb and make sure you have a carb gaskit that is about a quarter of an inch thick. this is an insulator type. if you dont have it get one. Run an aftermarket open element air filter under the hood. it will use up some of the hot air under the hood aiding air flow. Make sure you have as little obstruction to air flow around the engine as possible. Pertically the heater hoses get them up on the fender apron and not running along side near the exhaust. run insulation on your fuel line to the carb. Some people use and electric fuel pump in line with the stock pump and hit the switch to help push fuel through if it acts up. Dont use cheap gas for some reason it vapor locks easier. Try a different brand of gas. If in California the special gas they blend for the summer is no friend to us.

 

[mgweiss]

Vapor lock can be a very frustrating problem, I felt like pushing the old Bronc of a cliff a couple of times when it stalled out on the trail right after I thought I had fixed the problem. I put in a holly electric pump, plumbed the lines similar to Waverous, but every time I drove trails in the mountains the truck wouldn’t make it more than 15 min before stalling. Its very embarrassing when stock heep wranglers make it further up the trail than you can! If all else fails try installing a bypass fuel regulator with a return line back to your tank. This is what finally fixed my vapor lock problem. What happens is when you’re at idle, the carb isn’t using much fuel, so the gas just sits there in the fuel lines and heats up. Gas vaporizes at a lower temperate than your engine runs at causing vapor in your lines and carb, then the engine leans out and heats up even more making the problem worse. With a bypass regulator, gas will continue to circulate through your fuel lines and back to the tank when its not being used, so it doesn’t get a chance to heat up. I used a NOS bypass regulator form Summit Racing part # NOS-15851. I’ve also heard of people using an inline fuel filter with a built in bypass (3 port) from Napa which would be a lot cheaper than the regulator. Maybe someone else on the board has the fuel filter setup and knows the part number.

 

[t2jeff]

I remember a post a while back from some crazy kook that swore by this method. Clip a wooden clothes pin on your fuel line..........I dont know how the hell this would solve anything, but give it a shot. I think the post was pretty interesting......

out
JB

 

[americanhorses]

Just a thought. I notice you said 'when it gets below a 1/2 tank', and you live in ID.(cold and moist) If you have a open fuel system or leave the cap loose, The air moisture and cold will cause condensation and water in your tank. This could trick you into thinking it's vapor lock. Keep your tank full and see what happens.
Does it happen in summer?

 

[ASE-73]

[quote author=americanhorses link=board=5;threadid=14699;start=0#110881 date=1046368872]
Just a thought. I notice you said 'when it gets below a 1/2 tank', and you live in ID.(cold and moist) If you have a open fuel system or leave the cap loose, The air moisture and cold will cause condensation and water in your tank. This could trick you into thinking it's vapor lock. Keep your tank full and see what happens.
Does it happen in summer?
[/quote]

My same thought assuming cold weather. Use "HEET" 2-3 times per year to eliminate water as a potential problem. Also, make sure your intake has a "stove" for the winter. The carburetor venturi supercools and condenses the air to where a block of ice will form and restrict the carburetor with the effect much like that of vapor lock. After sitting for 10-15 minutes, the ice melts and everything works fine (for a while).

 

[howiebilt]

I will get you the NAPA part number today after work . It really made a difference and it is very cheap . I tried everything that has been mentioned so far ( except that clothes pin) and the return line was the deal

Save your money on the "HEET" and get yourself some "THERMO-AID" while you are at the NAPA store getting your new filter/return device ;D the thermo-aid will actually mix with the gas and allow it to be run through the system . Heet only keeps water from freezing .

The NAPA part # 3040 is an inline fuel filter with a 5/16ths inlet and a 5/16ths outlet as well as a 1/4th outlet . run the filter as you would usually but run the 1/4th outlet back to your tank . GOODBY vaporlock

 

[howiebilt]

[quote author=howiebilt link=board=5;threadid=14699;start=0#110888 date=1046370492]
The NAPA part # 3040 is an inline fuel filter with a 5/16ths inlet and a 5/16ths outlet as well as a 1/4th outlet . run the filter as you would usually but run the 1/4th outlet back to your tank . GOODBY vaporlock
[/quote]

;D ;D ;D ;D ;D ;D ;D ;D ;D ;D

 

[green77]

thanks for all your help. where do you suggest putting the line back into the tank? any place better than another. thanks again

 

[howiebilt]

[quote author=green77 link=board=5;threadid=14699;start=0#110957 date=1046383543]
thanks for all your help. where do you suggest putting the line back into the tank? any place better than another. thanks again
[/quote]

next to the gas filler hose there should be two smaller hoses that come from the charcoal canisters or vapor bottle . I discontinued using them so I used one of them as a return line or You could splice into the overflow hose on the filler neck .

 

[mgweiss]

My '69 never had a charcoal canister, so I put a plastic T - connector into the overflow hose that Howiebilt mentioned. If you have two tanks, just don't switch to the front tank until the rear is empty. Otherwise the return line will overfill the tank and gas will start pouring out of the cap.

 

[a67and77]

[quote author=t2jeff link=board=5;threadid=14699;start=0#110864 date=1046365666]
I remember a post a while back from some crazy kook that swore by this method. Clip a wooden clothes pin on your fuel line..........I dont know how the hell this would solve anything, but give it a shot. I think the post was pretty interesting......

out
JB

[/quote]

My 77 has a steel coil wrap around the fuel line in the engine compartment. But as far as close pins I used to have a 75 that would vapor lock all the time till my uncle said to put metal close pins on the fuel line like cooling fins. Seemed to work... ;D

 

[green77]

sounds great............. now i have a weekend project. thanks for all the help. howiebuilt, nice rig. i ran across your website quite a while back when i was putting my 77 together (about a year and a half ago) good stuff. thanks again to everyone

 

[GRIZZLY]

I did the aluminized wrap front to back and don't have any problems.....

 

[howiebilt]

[quote author=green77 link=board=5;threadid=14699;start=15#111103 date=1046408985]
sounds great............. now i have a weekend project. thanks for all the help. howiebuilt, nice rig. i ran across your website quite a while back when i was putting my 77 together (about a year and a half ago) good stuff. thanks again to everyone
[/quote]
thanks ;D