During the cruise at Turkey Run my '56 Ford vapor locked and died. I have steel fuel lines. My son told me that if I changed that steel line to a rubber one this would fix that problem. Is that so? Also I had this problem back in the '70's with a Ford truck in the mountains in Colorado. I put an electric fuel pump on it and fixed it. Whatcha think?
I use electric pump, mounted back close to the tank wired as a backup, not running constantly. I wire it through the ignition, plus another switch in series so that I can shut it off or power it up at will, that way it isn't running all of the time.
rubber lines will break down over time and more rapidly with the additives in today's fuels. Insulating the fuel line may alieviate the problem temporarily, fire sleeving commonly used for spark plug and wiring could be used. To cure a vapor lock problem you need to either move the fuel line away from the heat source or install a return line. I have used bypass style regulators, bypass style fuel filters and have rigged a return line into a multi-carb fuel block with a 0.060" carb fuel jet inline. the trick with any of these is to have the point of return as close to the carb as possible.
I know this will be unpopular but I personally don't believe in vapor lock as all the folk lore has touted. I never could understand how a car can perform beautifully for many years and then all of a sudden it needs clothes pins, insulation or a fuel line relocation to keep it running. I'm more inclined to think that it is a weak fuel pump or other problem. I don't doubt the successes that people have witnessed. When I was a teenager I heard the same thing (and not from a hot rodder) I tried the old clothes pins and tin foil tricks. It did nothing. I think it turned out to be a failing coil but I can't remember for sure. I just think it's more folk lore than factual. JMHO
Vapor lock is the real deal. I modified the exhaust on my old truck that had run perfect until then. After changing the exhaust it started running like crap after it warmed up. I got to looking and the exhaust was blowing straight at the fuel pump(electric). I rerouted the exhaust to where it did not blow on the fuel pump and again the truck ran just fine. Makes no difference if you have an electric or mechanical fuel pump. I have experienced it with both.Later, Dick
I have experienced it as well--usually gas line too close to exhaust or lying on engine--Elpolako has the right suggestion--keep the fuel in circulation
Yes no doubt but you changed something to cause it. That makes perfect sense. It's the cases that all of a sudden for no reason develops vapor lock that I don't understand. I did not mean to imply that it doesn't exist. I just think it gets diagnosed too often.
Vapour Lock. Why now and not before? Good question! For years in the days of mechanical fuel pumps we pulled our fuel from the tank to the fuel pump under low pressure or below outside air pressure. As the pressure is reduced the boiling point is reduced (Charles Law.) So any lines near anything extremely hot would easily boil if the fuel stayed by that spot too long. Like at a stop light. The pump itself is mounted on the engine and gets extremely hot as well so even though one side of it is under pressure it is still hot enough to boil modern gasoline. For many years the fuel companies formulated our summer gas to contain an additive to stop this. Seems to me Texaco was one of the first when engines started getting big and engine compartments crowded. Now with 99% of vehicles being EFI and the fuel is pumped from the tank mounted pump under very high pressure the whole thing is irrelavent as far as the fuel companies are concerned. THey are not concerned about the 10 of us out of every 1000 still using a car with a mechanical engine mounted fuel pump a couple of nights a week. The additive to prevent this is no longer used as it has as far as they are concerned no function now. A couple mentioned an electric pump and that will work. I didnt want to listen to the roar of a big pump on my 426 Max Wedge while going to cruise night so I tried a lot of things. Insulating the gas line with a heat sheild like the original Max Wedge cars had but still had the problem. I kept feeling the fuel pump and knew that if I poured cold water on it or held a cold soaked rag on it it would cure the problem for the moment so i set out making a heat shield. I got one that works perfect for our BB mopar engine with mech pumps and many on the 62 to 65 mopar website now use it. There is a pattern there of it and it can be adapted to any engne. Be sure to make sure the shield reflect the heat of the block away from the pump. Despite its seeming simplicity it works very well on both small and BB mopars and there is no reason to think it wouldnt solve the problem for other makes too. Mine would quit at long stop lights in 90F weather and was almost impossible to restart. Also on hot days if I went into a store for more than a few minutes and the car was hot it would almost not restart till cooled down. This cured it completely. Just to be sure i tried it on my buddys cars as well since he was also having a terribe time with his 440 powered 64 Dodge. He says it has never happened since we made it and installed it. Like hooked on phoenics it worked for me. Don
This is an excellent explanation. I used to always get it in the mountains of CO in my Ford F250. This was at altitudes of 10,000' + which also lowers the boiling point. Do you have pictures or something of the heat shield you made? Yes! Vapor Lock is real! I was in traffic for a long time at Turkey Run and that did it for sure. The engine never got hot but I know vapor lock when I experience it.
It is on the tech tip section of this website. I believe he worked to make a printable pattern from the photo. http://www.1962to1965mopar.ornocar.org Don
when we first bought our '86 motorhome with 454 it would sputter,sometimes die and hard to restart when it was very warm outside. well, we also would be running a/c--so i routed the a/c drip line so that in dripped the cold water on top of the mechanical fuel pump and kept it cool -no more problems-
Yep, was vapor lock. I'd bet my ass on it. I've seen it and know what it acts like. Once I got away from all that traffic and things cooled back down it was fine and has been ever since just like it was before all that sittin' in traffic. That's the one and only time it ever did it.
I know some people who have gotten vapor lock in recent years when it never happened to them before. I think it's partly due to whatever additives they've been adding to the fuel lately. Cars that were on the verge of vapor lock due to a really hot engine compartment with headers and poor air circulation are more prone these days to vapor lock. Some of them fix the problem by getting better ventilation under the hood, or by messing around with electric fuel pumps, or rerouting their fuel lines away from hot areas.
The first thing I'm going to do is the rubber fuel line. If that doesn't fix it I'll do the electric fuel pump thing as an <meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 10"><meta name="Originator" content="Microsoft Word 10"><link rel="File-List" href="file:///C:%5CDOCUME%7E1%5CEJ9442%7E1.STI%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"><!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><style> <!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} --> </style><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman";} </style> <![endif]--><!--[if gte mso 9]><xml> <o:shapedefaults v:ext="edit" spidmax="1026"/> </xml><![endif]--><!--[if gte mso 9]><xml> <o:shapelayout v:ext="edit"> <o:idmap v:ext="edit" data="1"/> </o:shapelayout></xml><![endif]-->[FONT="]auxiliary[/FONT] fuel pump.
Customline Vicky,Sorry I didn't get to catch up with you at Daytona. Don't feel too bad,my Hudson was on the verge of dying at Belair Plaza too. Hudson addressed the issue back then with heat shields and insulators under the carbs.Even the fuel pump got a "fiber" insulator on the base and fiber washers under the bolt heads to slow the heat transfer.Funny thing,is I never had an issue till this year.Hamb Drags in 06 had me driving(and crawling) in MO and OK in 100* plus heat and it was fine. OK,it did get a little pissy if I had to restart within 15-20 minutes of shutting it off when hot.Anyhow just letting you know I was dealing with it too and will be installing a Carter electric pump back by the tank for when this happens again.
I had this same issue on my 56 Buick (notorious for this). It was fine in normal SoCal weather (70-80 degress), but once it started to get really hot outside (85-100+ degress) it would vapor lock. I would have to wait between 30mins to 1 hour and let the car cool down before I could start it. It started right up after driving in normal weather, but once it got hot... I was in trouble. I tried the clothes pin trick. I tried insulating the rubber fuel lines. Nothing worked for me. Finally, installed an electric fuel pump near the tank and problem solved. Hasnt vapor locked on me since.
I probably saw ya there and didn't know it. Was that your Hudson parked there with the HAMB'ers? I went up and down on Thursday night and things worked fine. It was on Friday night that things really got jammed up there southbound on A1A before Bel Air. Once I got off A1A I went to Riverside and northbound to the bridge. Once I was moving things were fine. On Saturday night I was with my son in his red/white '56 Chevy pro street rig. That was an experience let me tell ya .. I think the electric fuel pump is probably the answer. The car wasn't all that hot and of course the weather wasn't hot either. 190 was as hot as I saw on the car. I've got a 1" spacer under the carb too. Maybe see ya next year. I want to go to the Moonshine Festival in N. GA next year too.
Vapour lock is when heat causes the fuel to evaporate before it reaches the carburetor. It does not cause lack of fuel pressure, but results from insufficient fuel being pushed through the lines to overcome the evaporation through heat. I just replaced a faulty electric fuel pump which caused the engine to lean out when I got on it - under any atmospheric conditions. Exact same symptoms, but NOT vapour lock and not heat related - lack of fuel pressure plain and simple.
I have always installed a return line system in all my cars and never have had a vapor lock problem in up to 115 degree temperature. Simply add a fuel filter up near the engine that has the return system line built in. I run a line back to the tank and install a nipple in the gas fill tube about 6" below the fill cap. When the carburetor needs gas the needle valve opens and lets gas into the fuel bowl. If it don't need fuel it flows back to the tank and keeps the fuel moving at all times in both lines. Moving fuel has a less chance of boiling in the lines. The biggest thing is routing the lines so that they are away from any heat sources.
I had vapor lock issues on my 53 Merc flathead v8 a couple of years ago on I80 in Wyoming. The temp outside was in the 90's that day and every 100 miles or so the engine would die from fuel starvation. I would cool off the fuel pump and lines and the engine would start right back up. The weird thing was the day before it did not stall once during a 300 mile drive. The funny thing was the day after all the vapor lock. It vapor locked twice before needing gas. Got the gas put in the tank and did not vapor lock the rest of the way. Reason: OCTANE RATING. In Wyoming, the octane is at 85, while in Colorado it is 87. That measly two octane points were causing the vapor lock. I now run 89 octane if available and it seems to work fine. Furd didn't think too well when they put the fuel pump on the top of the intake manifold. It sure gets hot up there, so that isn't helping either.
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