Vapor Lock

[Oldgearz]

1954 Y-block 239 here, and it loves to vapor lock with temp above 85 degrees. After running at 60, I go into a store and come back and it starts right up, but stalls or bucks badly after a block or so. I've put heat tubing (cloth stuff) on the gas line above the fuel pump, nothing below except rubber gas line back to the new gas tank. I've heard non-ethanol helps, but I haven't tried that yet. Anything else I can do?

 

[bhgreg]

Oldgearz non ethanol fuel helps, also maybe keeping the fuel tank fuller, to keep the fuel in the lines cooler. A phenolic spacer under the carb may also help keep the fuel in the carb cooler.

 

[taycotrains]

I finally fixed my issues recently…

Electric fan in front of the radiator
Carb spacer (as mentioned above)
6 blade fan on water pump side.
Completely rerouted the fuel line and insulated it.

Don’t waist your time with blue racing antifreeze or water wetter products (complete waist of money)

My car did the exact same as yours…

Park it
Come out start it
Drive off and it drops dead !

Very embarrassing !

BT

 

[paul2748]

erased

 

[Oldgearz]

taycotrains: where did you find a six blade fan that fits?

 

[41Fordor]

A back up electric fuel pump located on the frame rail near the tank that can be switched on and off when needed. The 6V Carter can allow the mechanical pump to draw fuel through it even when off. It must just be insulated from the frame to run on positive ground.

 

[taycotrains]

taycotrains: where did you find a six blade fan that fits?

Can’t post a link because not enough post counts…I guess someone found out about the great bazooka bubble gum heist I tried to pull off at the local candy store back in 1968…

I got it off Amazon

I first bought a 18 inch

No good to big

Then I exchanged it for a 15 inch

That worked !

I might have gotten by with a 16 inch but I just left it.

Bob T

 

[Flathead Fever]

I would check the pressure of you fuel pump it might be getting low which would cause vapor lock. I was fleet mechanic during carburetor years and never saw vapor lock on a large fleet of vehicles until a suburban went up the mountain and the guy said it just ran out of gas until he let it sit for a while and then it started back up. I drove it around down the hill and I could not find anything wrong, so I drove it up the mountain and sure enough at around 5000' it started running out of gas. I had a bottle of cold water, and I poured it on the fuel pump, and it started right up. The mechanical fuel pump wasn't quite putting out the pressure it should, the pressure went down as I went up in altitude. This was the only time I ever saw vapor lock in my 30-years as a mechanic. I don't know if your car is perfectly stock or has been modified. Make sure all the fuel lines are running away from hot sources. You might try my water trick on the fuel pump. Also, I've had stuff plug the fuel pickup tube. It will let the vehicle run for a little bit until it plugs the tube. then I'd shut it off and it fell off the tube, and the car will start again. I had a '33 1 1/2 truck that did that. It would start at the house and get about a block. A lot of these cars' problems are because they are old, not because they need to be modified. If it ran once for years and years then there is no reason to modify anything, you just need to find the problem.

When your engine stops spray some carb cleaner in the carb and see if it runs. That will tell you if it's fuel or something else. Look down the carb and operate the linkage and see if it squirts fuel. Pull the fuel line off the carb and put it in a bottle and crank it and see if its pumping fuel. Pull the line off of the pump from the tank and blow air into the tank and see if fuel flows out of the line. At work we had spare everything on the shelves, so it was easy to throw a new fuel pump on and that usually fix it. Every once in a while, you got one that took some research. We also had the luxury of switching carbs between vehicles to see if the problem followed the carb of not. We also hooked a fuel pressure gauge between the carb and pump to see what pressure we were getting. I'll probably think of a bunch of other stuff. There were four of us mechanics, sometimes it took all of our brains to figure out the weird ones. We even had Ford dealer tuneup guy that was an excellent carb guy, he taught me "a lot". He owned '67 and a '70 Shelby GT-500 and I owned a '66 GT-350.

 

[Oldgearz]

My car is almost perfectly stock, except for the rubber fuel line from the new tank to the fuel pump. A long while back I bought my son a 1950 ford coupe for school use and he carried around a water pistol to spray the lines and fuel pump when she vapor locked (100 degree weather). I've ordered 2 different water pistols but the ones today all leak. With all this AI and stuff, they can't make a water pistol that's any good!

 

[Flathead Fever]

The rubber line all the way from the tank to the pump might be the problem. I'd start by replacing it with an original style steel line run it the stock position. I've seen rubber lines squeeze shut and block off the fuel. No car uses rubber lines all the way from the tank to the pump, just a short piece at the tank and a short piece at the engine but it's a steel line all the way under the car away from the exhaust. That what I mean about things that have been changed from the factory, it ran once with a steel line and now it doesn't. Put it all back to how it once was from the factory. More than likely the original steel line got damaged or plugged and somebody replaced it with a rubber hose. Now if you absolutely do not want to replace the rubber hose you can still change it to fuel injection rubber hose, that stuff is tuff and will not collapse but at the price per foot I would go steel. The problem you might have is learning to make the bends, that takes some practice. The material is pretty cheap and so are the bending tools. Don't forget to flare the ends so the rubber hose doesn't slip off. Those you practice making the flare on the pieces you bent wrong. See if they make repro steel lines. I'm not saying that's what's wrong but that's where I'd start, it needs to be done anyway.

 

[Oldgearz]

Thanks all. Good advice here.

 

[norcalal]

All good advice. Put some marvel mystery oil or ATF in the tank just before you fill up. It worked for me!

 

[Oldgearz]

All good advice. Put some marvel mystery oil or ATF in the tank just before you fill up. It worked for me!

I use that in my Model A. Didn't thing to try it with the Y-block. I'll do as you say and report back. Thanks

 

[dmsfrr]

taycotrains: where did you find a six blade fan that fits?

Oldgearz,
Are you looking for a 6 or 5 blade fan? I have a 5 blade over here from '66. It's 18 inch diameter and been gathering dust for several years. Light surface rust is from before it arrived here. I bought it as a spare / backup for a 4 blade and never installed it.
Looks almost like an aftermarket flex-fan due to the thin blades but is an oem part.
There's a 2 inch spacer and 4 mounting bolts in the box with it. Bolt spacing is 1 & 3/4 inches. Center hole looks like 5/8.
You can have it for the shipping cost.