Vapor lock, possibly?

asapguy

asapguy

Senior Member
Just acquired a nice 55 2dr Fairlane from my uncle. It had to be transported from Iowa the PNW in an enclosed trailer so gas was at 1/8 tank. I took it for the 1st ride with my wife after adding 2 gal of gas from a can. It was warm day, mid 80's. The car ran fine to my son's house 6 miles away. it was shut off there for about 15 mins & started right up for the return home. About a mile after leaving it start crapping out & quit. Thinking it was still low on gas I called my son & he brought me 5 gals. We had waited about 15 mins for him to bring the gas but it started right up again after adding gas. Started home again another mile, same thing & it quit. We were going down a very long hill and able to coast to parking lot. Again after sitting about 10 minutes it started up & made it home. I'm guessing vapor lock The fuel pump looks new. I used non-ethanol gas.
 

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asapguy said:
... The fuel pump looks new. ...
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A new fuel pump? it depends on where it came from and how recently.
Virtually all the new replacement mechanical fuel pumps in the last 3 years are made in china and they're defective in the box.

If it's a rebuilt older pump they are much better.

Probably a good idea to double check the fuel pump pressure and flow.
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If when it started right up after waiting 15 minutes, you didn't have to crank it over to refill the carb, and it actually did start right up, then I 100% agree with Alaska Jim as far as a bad condenser or coil, especially if made off shore like China.

Sal
 
Vapor lock is when the fuel boils and turns to a vapor between the tank and the carb. It can happen on a hot day at high altitudes where the atmospheric pressure is not as high as lower elevations. We had that problem on some of the phone company's Suburban's when their fuel pumps were getting old and they would only put out 5 lbs. of pressure instead of 6. That was all it took for them to vapor lock on a hot day at 6000' elevation. They would not do it down in the valley. If they did it we poured cold water on the fuel pump it would run again for a while. That is the only time in my 30-year mechanic career I ever saw actual vapor lock happening. I doubt that is what is wrong with yours, it's possible but not my first choice for quitting. Next time it quits immediately remove the air cleaner and see if the accelerator pump is squiring fuel, if it is you do not have a vapor lock problem or probably no fuel problem at all. I's most likely ignition related like a bad coil, condenser or no voltage to the coil. It could picking stuff up in the tank and plugging the tube until it quits. Once the engine shuts off and the vacuum from the pump is gone the stuff falls away from the tube and it will run again for a while. It could also be a plugged vented gas cap not venting the tank. When you release the cap, it should not make a sucking sound. Thats' kind of a rare problem but it does happen. If your accelerator pump is squirting fuel the carb has fuel so those cannot be the problem. At home you can take a heat gun and warm the coil or distributer up and see if it quits.
 
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I talked with my uncle who I got the car from, he said he had this problem when doing a couple of parades. He said he removed air cleaner & poured a little gas in the carb & it fired right up. He sent a new electric fuel pump with the car. I also see Bob Drake sell a heat shield that fits under the carb to prevent vapor lock. I have a new 6V Autolite coil still in the box & a couple new condensers I'll try those also.
On one of my Model A's I've had a problem with the coil getting hot if points closed & the pop out ing. switch doesn't open when turned off. The coil gets so hot you can hardly touch it & won't start. Starts right up when coil cools down but never quits when driving it.
 
My experience 99% of the time; bad condenser. All available condensers are made overseas with very poor quality, workmanship and substandard materials. Some are bad right out of the box. One time it was a bad ignition coil. Make sure you don't have something blocking the gas tank vent tube (which exits near the gas cap). Could also be so much crud in the bottom of the gas tank that the crud gets sucked into the copper screen/sock, blocking gas from exiting the tank (until you shut off the engine, then the crud falls off the sock and allows starting again).
Heat is the main enemy of the offshore coils and condensers. Try to keep engine coolant level to provide a normal operating temperature below 190 degrees F. I use 160 degree thermostats.
 
My 63 Ford Galaxie with 390 would have a very slight surging going down the highway. Someone told me to change the coil and I did. It fixed the problem. The coil looked to be fairly old, so I didn't suspect China made.

On the other hand, in the 70's, I had a 46 Ford PU that would run great for months (I used it for a daily driver for a couple years), then all of a sudden, it would stall. Park along the road for a while, and it would start and go on its way. But, it would do it again other times. I finally pulled the sending unit off the top of the gas tank, under the seat and looked inside. There were three apple seeds moving around on the bottom of the tank, and sometimes they would get pulled into the gas line and plug the flow. After sitting a while, the vacuum would release, and they'd move somewhere else for a while. I don't know how those three seeds got in there.
 
asap, agree with mercman! Beautiful '55 Two Door! Also am in the camp of try a new condenser first. Imagine you're still 6 volts? Any chance you could ask your uncle if he ever had a similar problem before the car was shipped to you?
 
I did talk to my uncle, he said the only time he had a problem was when doing a parade and going slow. Never quit when he drove it on trips of 10-30 miles, even warm days.
 
OK, lets say it's the condenser, where the best place to get a decent one? Are 6V condensers pretty much the same? I have a few boxes full of Echlin & other NOS electrical parts, points, condensers, vacuum adv., dash pots, switches etc, from the 50s & 60s. These were parts deemed obsolete in the mid 70's and were supposed to be destroyed. A friend was in wholesale parts business but knew I was into old cars so gave me the stuff.
 
Just got a list of everything done to the 55 Ford since my uncle purchased the car in Sept of 2005. The total comes $17798.48. Everything in the eng. electrical system has been replaced, points, condencer, coil, plug wires, dist leed, cap, rotor. New fuel pump, carb & rebuild, fuel lines, filter. This list also includes all the, plating, upholstery, new glass, refinishing dash, radial WW tires, 3 batteries. Granted the condenser may need to be replaced again, so that's my 1st priority. Thanks for all the input.
 
asapguy said:
OK, lets say it's the condenser, where the best place to get a decent one? Are 6V condensers pretty much the same? I have a few boxes full of Echlin & other NOS electrical parts, points, condensers, vacuum adv., dash pots, switches etc, from the 50s & 60s. These were parts deemed obsolete in the mid 70's and were supposed to be destroyed. A friend was in wholesale parts business but knew I was into old cars so gave me the stuff.
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I wouldn't toss any of those old parts unless they are confirmed defective and not repairable. Old parts that were routinely thrown away back-in-the-day are often still better quality than the current crop of 'off-shore' made replacements.
Old dual action fuel pumps are in particular demand by '55/'57 T-Bird owners as cores for rebuilding. The new replacement fuel pumps all come from china and are Defective in the box.
Even old Made in the US condensers can still have a longer usable life than the cheesy replacements.
 

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I completely agree with dmssfr, except that I personally would not use NOS (or old possibly used) condensers or coils as the insulating material can degrade with age making them defective. But I prefer OEM fuel pumps, carburators, generators, power steering components and certain electrical components such as starter solenoids, starter neutral switches, horn relays, anything having contacts. The chinese made repro's are total junk. I'll take a used one of any of these over a new chinese made one and rebuild the old one myself.
 
asap guy, very good advice from all the members.
Here is a strange thing that happened to me a while back.

I bought an older Motorhome with a big ol' V/8 in it.
Before I paid for it, I just drove it for a couple miles and it seemed to run good.
Arrived back at the guys house after about 5 mins, and paid him for it.
It had over a half tank of gas, so I started the hour long drive home.

I went about 15 miles, and it started chugging and quit running. I pull 'er over
and loosened the gas cap a bit. Jumped back in, turned it over for a minuet
and it started, so I took off, thinking maybe the vent in the cap was plugged up.
Went about 15 more miles and she quit again. I got out and looked it over to
see if there was a gas leak or something. none found, so I cranked her over
and after a bit it started up and so I hit the road again. Went about 15 more
miles and was dang near home. Chug, chug, chug. It quit again... NUTS.
Cranked her over and after a little bit, it started up, and I hit the gas for home,
and made it the 3 miles.
Ran in the house to find a cold one and slammed it down, what a relief. :)

I called the seller up and told him the story. He said he had his son put
a NEW fuel filter on it two days ago and was sorry to hear of a problem
and to let him know when I find out what's wrong. Goody-Goody :rolleyes:

The next day I found the NEW fuel filter his son put on, and looked at it
and seen the Red Arrow was Pointing the WRONG WAY on the glass bowl.

I took it off, turned the filter around and drove it about a half an hour, and
the next day drove it for over an hour, pulling our boat. NO Problems.

Found out that the "INLET" end on a filter will hold a lot of Crap particles,
but the "OUTLET" end of a Fuel Filter holds VERY FEW Crap particles...
So, it's a long shot, but Maybe, just Maybe your fuel filter is on backwards

Good luck, hope you find your problem...:cool:



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I had this Happen on my 55. It was the vent hose from the gas tank to the gas cap tube. Back then gas caps were not vented. It's a rubber hose underneath the car. It gets old and collapses. I replace it all is fine. Good luck.
 
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