1957 Stalls out after running half hour

[1954MGTF]

MY 57 RUNS GREAT, BUT stalls out sometimes like out of gas when it has ran 45-60 minutes, but starts right back up. Have new back up electrinc fuel pump box i can flip with a switch. i think it is in ignition maybe when it heats up. Could it be the coil? How to test? Could it be the petronix distributor. And what petronix unit is used on a 57? Thanks.

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[paul5456]

When it stalls, does it cut out right away or does it slowly die? Usually, the first would indicate an ignition problem, the second a fuel problem.

Next time it stalls out, go to the gas tank and take off the cap. If you get a whoooshing sound, it's a bad gas cap (must be a vented cap). The other possibility is something in the tank clogging up the exit of gas and when the car dies it falls back and then the car will start again. Then it can repeat itself.

 

[biddle]

Please use the four-digit model year in the subjects of your future posts as prompted. This aids with Google and our site search. I have revised to "1957".

 

[vernz]

I had a 1968 Thunderbird 429 with a similar problem, although quite a bit less than 45 minutes. In my case it turned out to be bent fuel line that was restricting flow. After the car died, vacuum on the fuel pump side of the bend would refill the fuel line and it would then run for a while again. My exhaust system had been replaced shortly before this problem appeared and it turned out that the line was bent when the exhaust system work was done. Good Luck!

 

[Ron Sessions]

When it stalls, does it cut out right away or does it slowly die? Usually, the first would indicate an ignition problem, the second a fuel problem.

Next time it stalls out, go to the gas tank and take off the cap. If you get a whoooshing sound, it's a bad gas cap (must be a vented cap). The other possibility is something in the tank clogging up the exit of gas and when the car dies it falls back and then the car will start again. Then it can repeat itself.

Another possibility could be vapor locking. When it dies out, look for air bubbles in the glass fuel filter. If you have a return line to the gas tank, this probably isn’t the problem.

 

[Frankie the Fink]

It could well be vapor lock with modern gas, hot weather and an old car.
If it starts to stumble in traffic and you can get it going correctly by switching on your electric booster pump immediately then that's your issue, not ignition. Be aware that adding a booster electric pump to an older car can create dangerous conditions so only use it temporarily and when needed:

1) If there is not a provision for an oil pressure, pump "shut off" switch the pump can continue to operate after a crash (unlike a mechanical pump) creating a huge fire hazard.
2) If the electrical booster pump operates THROUGH the mechanical pump and the mechanical pump rubber parts should fail, the fuel will be injected directly into the crankcase without noticeable symptoms when driving...

There is really no good test for an intermittent ignition coil issue related to heat/vibration other than replacing it with a "known good" coil as a troubleshooting tool.

Any vacuum gauge is nearly alwasys also a fuel pump pressure gauge and can be used to test fuel pump pressure but you also have to check volume. Pressure is NOT volume. Cranking the car with the igntion coil wire removed and the fuel line in a glass mason jar will check volume. The tests are described in this document that came with my vacuum gauge:

 

[willcarterdc]

When it stalls, does it cut out right away or does it slowly die? Usually, the first would indicate an ignition problem, the second a fuel problem.

Next time it stalls out, go to the gas tank and take off the cap. If you get a whoooshing sound, it's a bad gas cap (must be a vented cap). The other possibility is something in the tank clogging up the exit of gas and when the car dies it falls back and then the car will start again. Then it can repeat itself.

I’d definitely check the gas cap to see if that’s part of the issue. I had similar problems and am now on my *fifth* gas cap in trying to solve it.

The one that came with the car was non-vented, so I replaced it. The second and third ones (different brands and different vendors - one was a Stant; can’t remember the other one) were both supposedly vented but the venting wasn’t working properly: I would get a very big “whoosh” even after a short drive (one time, the pressure was so strong that it blew the gas cap out of my hand as I was taking it off because I only had a light grip on it). I cut away some of the rubber gasket inside the third one as someone on this forum or elsewhere had recommended, but that didn’t change anything. The fourth one is a vintage reproduction from one of the usual t-bird suppliers in which I drilled a very small hole. That one works - when I drive with that one on, I no longer get the “ran out of gas feeling” stalling that I was getting before and I don’t get a “whoosh” when I open the cap after a drive. But (1) it continues to strike me as potentially unsafe (even though it’s only a very small hole, I now only ever fill the tank half full for fear of gas sloshing out; plus, the fumes themselves are flammable) and (2) there’s obviously a stronger gas smell when driving with that cap, which isn’t pleasant and which reinforces my safety concerns.

So, I recently bought a fifth one. The venting is better - still a “whoosh” when I open it after a drive, but less than with the other non-drilled caps. But: the car now again stalled while sitting at a stop during a 30 minute drive yesterday. I flicked the electric fuel pump on and was able to get it restarted, but it was a bummer.

I say all that to say:

1. Definitely check your gas cap.
2. Could folks who have vented gas caps that actually work properly *without needing to drill a hole or cut away the gasket* please post the brand, model, and vendor from which you got it?

If my experience is anything to go by, there’s a very high failure rate with the vented caps, so “crowdsourcing” might be helpful.