1950 Buick - starting hard when warm

Hi guys,
Hope someone can help shed some light on this problem. I have a 1950 Buick Special 248 6volt. It starts fine when it's cold. However after I've driven it awhile and it gets hot and I shut it off and go to restart it, it starts really hard. By that I mean the engine turns over and I have to hold the pedal to the floor for about 15-30 seconds of continuous cranking before it finally starts. I've tried not touching the gas at all (I also have a push button starter), tried holding the pedal half way down, and putting it to the floor.

As I said it starts fine when cold, but has a hard time starting when it's warm. Any advice from anyone would be greatly appreciated.
Thanks
Scott

I have the same problem with our roadmaster 1949 does anyone have an answer for this?

Volitile fuel could be the cause, 15 second turn over of starter is normal when hot start as per manual, gas pedal all the way to the floor, and hold it, dont pump, 15 to 20 seconds normal.

Heat riser may be stuck, should be free, and kept that way with GM Heat Riser solvent. Comes in a can like shaving cream, shake it good, and the stuff that comes out is grey color. Spray all friction points, and tap the shaft back and forth gently, when free, try working lever gently up and down until it is free.

Should have a bi-metal strip coil that opens and closes the valve, and a spring on the other end to control rattle of the lever when it is working properly.:thumbsup:

After a google search, I found this link and I wanted to verify that this is what you are talking about.

http://www.acdelco.com/html/pi_vehcare_shop.htm

the selection is Super Penetrant. Part number is X88A 12302866

It looks like a shaving cream can. I want to make sure I get the right solvent. I have tried soaking the valve in gasoline but it didn't make a difference.

I had the same problem with my 52 Super and to correct it I removed the top of the carburetor and set the float slightly lower. The new fuel seems to expand more than the old stuff did and it seems to flood the engine when warm.

Would an Electric Fuel Pump, improve staring when hot and after it has set a few days, and if so could you install it with the current vacum pump back by the gas tank?

Electric pump would be the way I would go, in conjunction with the manual pump. Just enough to get the fuel up to the carb when you turn the key on. Modern fuel evaporates quicker than old leaded fuel. Once running, the electric pump cuts out, and you run with the manual pump. This can be done electronically or with a manual switch. Talk to your local auto electrician.

I have a 52 Super straight eight, I have installed an electric fuel pump back at the fuel tank and it only works when I turn on the toggle switch. I use it to prime the carb after it has been sitting for a month or so, then I pump it about 15 times, turn on the ignition switch and it starts. The electric pump has no effect on the mechanical pump. I have used this system for many years. My experience is only when it is cold, I have no problem starting when it is hot.