1955 stalling after driving for 5-10 minutes

[Jbud82]

Hello,
I am new to this forum and just bought a 1955 Thunderbird a month ago. It's an awesome car, but I can't seem to get it to run right. The car starts and runs perfect while in park, and for the first 5-10 minutes of driving. After 5-10 minutes of driving it starts to sputter and eventually stalls out. I pullover, put the car in park and it fires right back up and away I go for about 1/4-1/2 mile until it stutters and stalls again. It does this all the way back to my house. The thing I can't figure out is once it stalls out and I start the car back up and leave it in park, even rev the engine little it runs fine and will stay running fine until I shut it off. I have replaced about everything I can think of: new 6v electric fuel pump with regulator (bypassed mechanical), fuel filter, ignition switch, 6v ignition coil, distributor cap and rotor, adjusted the points, changed the spark plugs and wires. Had a shop put and new Holley carburetor on it. All this and I still can't drive it for more than 10 minutes. Any help would be appreciated.

This page contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

 

[dmsfrr]

Does air woosh in or out of the gas tank when you loosen the gas cap? If it does you need a vented gas cap. The fuel pump may be creating a vacuum in the gas tank.

Unrelated to stalling every 10 minutes... does it have the original Loadomatic distributor?

 

[Jbud82]

Does air swoosh in or out of the gas tank when you loosen the gas cap? If it does you need a vented gas cap. The fuel pump may be creating a vacuum in the gas tank.

Unrelated to stalling every 10 minutes... does it have the original Loadomatic distributor?

Sorry I forgot to put I replaced the gas cap with a new vented one as well. It does have the original distributor.

 

[Tom Alpers]

When it dies do not try and start it again. Take the air cleaner off and look in the carburetor and look to see if there is any fuel that squirts in from the accelerator pump when you open the throttle by hand. You should see fuel squirt but if it's dying and you don't see fuel that's a good indication its a fuel delivery problem rather than an ignition problem. One possibility, given that you have replaced so much stuff, is that there is a restriction in the fuel supply from the tank, which can be as simple as the gas cap on it is not a vented cap. No vent and no air can get in and the fuel pump can't pump any more fuel out. You can drive the car without the gas cap (don't drive around corners fast) and see if that fixes it. If it does, buy a new vented gas cap. You can also pull the gas line that comes from the tank off the electric pump and see if fuel dribbles out for as long as the line is off. If you get nothing that line may be plugged. For this test it helps to have a full tank of gas. You can also blow air backward into that line and see how hard or easy it is to blow air thru it.

 

[Jbud82]

When it dies do not try and start it again. Take the air cleaner off and look in the carburetor and look to see if there is any fuel that squirts in from the accelerator pump when you open the throttle by hand. You should see fuel squirt but if it's dying and you don't see fuel that's a good indication its a fuel delivery problem rather than an ignition problem. One possibility, given that you have replaced so much stuff, is that there is a restriction in the fuel supply from the tank, which can be as simple as the gas cap on it is not a vented cap. No vent and no air can get in and the fuel pump can't pump any more fuel out. You can drive the car without the gas cap (don't drive around corners fast) and see if that fixes it. If it does, buy a new vented gas cap. You can also pull the gas line that comes from the tank off the electric pump and see if fuel dribbles out for as long as the line is off. If you get nothing that line may be plugged. For this test it helps to have a full tank of gas. You can also blow air backward into that line and see how hard or easy it is to blow air thru it.

Thanks Tom... I will do that, and check the fuel line better that I have thus far. I do have a new vented gas cap as well. Could it be that I have an aftermarket carburetor and the original distributor isn't operating properly?

 

[sre]

I had 2 cars that basically had the same circumstances. The one was a lot of very fine rust/dirt in the gas tank. It would sit and run all day, as soon as I drove the car, from the movement of the gas in the tank the rust moved around and clogged the filter attached to the end of the fuel line. The other car would drive about 3-4 miles and shut off. After sitting a few min. it would restart and drive about 1/2 mile. I found that the main fuel line from the tank to the fuel pump was loaded with rust. The rust would gather in one spot and shut off the fuel supply. After sitting a few min. it would disperse and car would start, exactly like yours. I'm not saying this is your problem, but sounds like the same issue.

 

[Tom Alpers]

It is likely that the aftermarket carb, if its the modern style, won't send the right vacuum signals to the distributor for best performance but it should not change while you are driving. If it runs good at first, I don't think the carburetor being a different kind would be the problem. Since you have replaced so many ignition parts the most likely thing is a fuel delivery problem between the gas tank and the carburetor. If it was happening after an hour, one might think it's some electrical part getting hot and flaking out but it doesn't sound like its running well long enough to get much past warmed up.

 

[dmsfrr]

It is likely that the aftermarket carb, if its the modern style, won't send the right vacuum signals to the distributor for best performance but it should not change while you are driving. If it runs good at first, I don't think the carburetor being a different kind would be the problem. Since you have replaced so many ignition parts the most likely thing is a fuel delivery problem between the gas tank and the carburetor. If it was happening after an hour, one might think it's some electrical part getting hot and flaking out but it doesn't sound like its running well long enough to get much past warmed up.

Inside the distributor doesn't the timing advance continuously change while driving, to meet the engine load and RPM conditions?

 

[Grumpy Rick]

If that new Holley carb is not the teapot style like original, the original distributor will never work right with it. You need a later model 292 distributor. That is what I did. A Pertronix ignition in the new distributor also helped a lot. If the carb is a teapot...disregard.

I also suggest you might also try a new ignition ballast resister if you are still on the original ignition. It's on the firewall.

 

[sylvurhfox]

There are many great suggestions here. I have found in the past that a fuel pump is most likely to cause this issue. When the vehicle is sitting still, it requires little fuel to rev the engine. Under load requires more fuel and the engine will shudder and stall. I have also had the issue of debris plugging the fuel filter. Most of the time this would not allow you to continue until the filter is cleaned or changed. I also have a 55 and mine is still 6v pos ground. I had coil failures because the wires to the coil were backwards. The wire from the key needs to be on the negative side of the coil. Hope you find your problem before the summer driving period runs out.

 

[vernz]

Years ago I had the same problem with a 429 1968 Thunderbird. The car had some exhaust system work done to it and they bent the fuel line near the tank. It would slowly allow fuel to pass but not enough to keep the engine running. The engine would use up the fuel in the line then stall out. The vacuum left in the fuel line would slowly refill it, then the car would run until it again used up the fuel in the line. This cycle repeated itself until I got the car home and figured out what had happened. Vern

 

[airbus]

It is likely that the aftermarket carb, if its the modern style, won't send the right vacuum signals to the distributor for best performance but it should not change while you are driving. If it runs good at first, I don't think the carburetor being a different kind would be the problem. Since you have replaced so many ignition parts the most likely thing is a fuel delivery problem between the gas tank and the carburetor. If it was happening after an hour, one might think it's some electrical part getting hot and flaking out but it doesn't sound like its running well long enough to get much past warmed up.

nobody mentioned it but make sure your float level is adjusted properly

 

[SP6TIW2F]

I had the same problem after installation of the Holly 4160, distributor had been upgraded prior to carb., replacement and had issues with it stalling and just would not run. Problem was needle valves for the floats, see photo

 

[willcarterdc]

Two quick thoughts:

1. Definitely check the float level in the carb as someone suggested above. I spent many months chasing a persistent hesitation and stalling issue on my ‘57; turned out to be that the float level was too low.

2. Just because you bought a vented gas cap doesn’t mean the gas cap’s vent is working properly. Trust me, I know: I went though 4-5 different brands and models of vented caps - several of them from various well known and reputable T-Bird suppliers, not a random auto parts store - before finding one on which the venting actually works properly. (Before finally finding one that worked, I drilled a very small hole in one of the “supposedly vented but not working properly” caps. That worked too: but still glad I finally found a cap on which the venting works properly). As someone suggested above, driving with the gas cap off - slowly and no sharp turns, of course - will give you a sense of whether improper gas cap venting could be part of your issue.

 

[doug7740]

Below is an article I wrote on the 1955/56 Thunderbird vented gas cap.

doug7740
1955 Thunderbird Blue

 

[Birdielasalle]

The same happened with my '55 years ago. My mechanic cleared gunk from the fuel line to solve the problem.