Vapor Lock - How do I prevent it?
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Vapor Lock - How do I prevent it?
I've got a 79 4wd F250 Crew Cab 400ci, 4sd with factory AC that I bought last fall. The guy I bought the truck from installed an electric fuel pump cause he said he was having some vapor lock problems. One the first long trip I made last fall, it think it vapor locked on me after a long climb on the interstate (at least I think it was vapor lock, could see fuel bubbling and spitting air in fuel filter he mounted near the carb and engine was sputtering and hesitating.
My question is how can I prevent this vapor lock? Fuel line, rubber hose mostly, run along drivers side frame rail, under engine along cross member and then up to fuel filter at the front of the engine then to 2V carb. Would re-routing the fuel lines help? How about going to all metal lines or even metal braided? I'd like to take some action before the hot spring and sumer months arrive.
Leroy in NM
My question is how can I prevent this vapor lock? Fuel line, rubber hose mostly, run along drivers side frame rail, under engine along cross member and then up to fuel filter at the front of the engine then to 2V carb. Would re-routing the fuel lines help? How about going to all metal lines or even metal braided? I'd like to take some action before the hot spring and sumer months arrive.
Leroy in NM
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Vapor Lock - How do I prevent it?
Leroy, easiest thing to do is wrap fuel line in heavy type aluminum foil. Best solution would be to install metal line. The black rubber is absorbing heat, giving you the vapor lock. You might also fabricate a metal shield around pump, to help keep it cool. Pay special attention where it routes close to exhaust system. Good luck.
"Nothing lasts forever except natural stone and old Ford trucks." (Willie Nelson)
"Nothing lasts forever except natural stone and old Ford trucks." (Willie Nelson)
Cargo Master
Joined: Jul 2000
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From: Northern California
Vapor Lock - How do I prevent it?
I went to the junk yard and picked up some fuel line insulation from a 280zx, it's thick about 1/5" and looks like alum on the outside but you can see insulation on the inside. I'm going to wrap the fuel line in this stuff. You can also re-route the fuel line and add a carb spacer plate that has the alum plate for under the entire carb. I've seen these at Jegs and Summit, but it seems simple to make.
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Vapor Lock - How do I prevent it?
i would start by replacing all the fuel lines with steel, because the rubber does work but man it is soo dangerous. to make it easier go to NAPA, they have fuel line wrapped with a spring, like brake lines are coming from the master cylinder on newer cars. the stuff is really easy to bend by hand, but costs a lottle more. i would also replace the fuel cap. i believe that is the vented style, if it is plugged up that could cause the vapor lock. since you dont have a vapor return line coming from your carb, or do you???
mattb
mattb
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Vapor Lock - How do I prevent it?
Elkhunter - I agree with that metal fuel line is the best. The rubber hose is not safe over long distances. You can take a trick from the new fuel injected cars and run a pressure regulator and a fuel return line back to the tank. Just fabricate a return into the gas tank next to the outlet. This keeps the fuel cooled by allowing the unused fuel to return to the tank.
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Vapor Lock - How do I prevent it?
I've had success running lower degree thermostats. Cooler engine = Cooler gas.
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From: Nebraska Farm
Vapor Lock - How do I prevent it?
Don't put an aluminum spacer under the carb. Aluminum absorbs heat and will make the carb even hotter. One old Ford trick my uncle used was to clip a clothespin on the line before it got to the filter. What it did I don't know but it worked until it got really hot out.
Dave,
79 F-150 4x4, 390 w/C6, Edelbrock carb, 33X12.50 never will be finished.
Dave,
79 F-150 4x4, 390 w/C6, Edelbrock carb, 33X12.50 never will be finished.
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1983 Ford F350 Crew
I have , I believe is vapor lock. But, it must've just happened recently. I've had this truck for almost 10 years, just recently put on another bed. While the old bed was off, I replaced all of the fuel hoses. And the hose that goes to the vapor plug/unit in the gas tank. After I put the newer bed on, that's when the truck wanted to stall especially on inclines. Anybody think that it may be vapor lock or the vapor plug/unit? Or, maybe something else? Please help. Thanks.
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From: Cave Spring Georgia
Vapor lock is when the gasoline turns into a vapor in the lines going to the carb, usually because of the engine or exhaust manifold heat.
Sounds like you might have pinched a line. bad line, reconnected something wrong Or it could be sucking air from a loose clamp.
Sounds like you might have pinched a line. bad line, reconnected something wrong Or it could be sucking air from a loose clamp.
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From: Glenvil Ne
Something to keep in mind is that when you raise the pressure of a liquid it raises the boiling point. A lot of times vapor lock is not a heat issue but something else, at least in my experience. Gasoline at 10lbs of pressure has a boiling point of over 250 degrees. Also if it is "winter" blend fuel it will have a lower boiling point. I don't know how often you drive your truck, but if you put fuel in it when it was cold then you go out and drive it 2 months later and the outside temp is 70 instead of 40 you could run into a problem. I guess what I am saying is that it probably isn't a heat issue and you should investigate further. Especially since you said it was boiling in the fuel filter and not the carb.
Hotshot
Joined: Jan 2011
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From: THIS IS SPARTA!, ...Mo.
You said the PO put an electric fuel pump on it. I had an issue with one of those cheapy electric pumps from the parts stores. The pump itself boiled the gasoline because it got so hot. Once it cooled off, it would run fine again. Take that pump off and put the mechanical pump back on it.
More Turbo
Joined: Oct 2011
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From: down a red dirt road
yeah i have an e8012s airtex pump. its a solenoid style pump 5-9psi. an e8016s is around 4-5psi
it works great on the 302 in my mazda but when my mechanical pump blew out on my 360 i put that pump on the end of my power steerin bracket just to get me by for a couple days. it would get hot and stop pumping i would have to sit for five minutes until it would pump enough to drive.
they work better the closer they are to the tank as they push better than they pull and the cooler fuel from the tank keeps it from overheating.
it works great on the 302 in my mazda but when my mechanical pump blew out on my 360 i put that pump on the end of my power steerin bracket just to get me by for a couple days. it would get hot and stop pumping i would have to sit for five minutes until it would pump enough to drive.
they work better the closer they are to the tank as they push better than they pull and the cooler fuel from the tank keeps it from overheating.
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Vapor Lock
I have an 1985, fuel injected system, 5 OL 302. It starts with ease. When its really hot outside, and only after it's been run a while, if I let it sit for about 10 to 15 minutes, it juct cranks and is treally hard to start. I'm certain it's a vapor lock even though I've got an external fuel pump (in the frame). Once she cools, no problem. I've tried clothespins, but that hasn't worked.
I need to find a way to keep the lines cool. I'm going to try getting insiulation around them. That should do the trick.
I need to find a way to keep the lines cool. I'm going to try getting insiulation around them. That should do the trick.