Stalling Problem

[glen]

Took my `51 Kaiser out to a Sunday car show. Got there with no problem but when it was time to leave, it started up for a few seconds and then just sputtered out. No amount of trying would get the engine turned over. It wasn`t flooded, actually there was no gas getting to the carb.
I left it for 2 hours and then gave it a pump or two on the gas and it fired right up.
Drove (problem free) directly to my mechanic.
He started it up the next morn and went for a drive and after a short period the car wanted to stall, so he headed back and shut it down and tried to restart but it wouldn`t. Once again, carb not getting fuel.
He replaced the gas filter with a clear filter so he could see the gas flow if any.
He noticed that gas was slowly bubbling into the filter.
He checked the pressure from the fuel pump and that was OK.
Over night the fuel filter was fuel and it didn`t drain back and the car started but wouldn`t restart. The clear gas filter was dry again.
Fuel pump working=OK, Fuel filter=OK, Carb=OK, Gas= looks OK
So could it be trouble in the gas tank and sending line?
Do you have any ideas before he takes out the gas tank?

[Fid]

How warm was the weather there? This sounds like vapor lock.  It doesn't  happen much with newer cars with electric fuel pumps (although my brother told me his '05 Ford Focus vapor locks on extremely hot days) but it is a known and common issue with older vehicles, especially KF products.  What happens is the steel fuel line and fuel pump get hot due to being mounted in close proximity to the exhaust manifold,  you shut off the car, the hot steel boils the fuel away and you have air in the fuel line and pump. The carb is still full of gasoline so the car starts and when the fuel in carb is all burned, the air pocket in the fuel line does not allow new fuel from the tank to be pumped through and the engine dies.  You leave the car sit over night, it cools, and the pump pumps new fuel up and the car starts and runs fine... till you shut it off again.  
Many owners install an electric fuel pump to supplement the manual one.  I had a '51 Kaiser which did this badly and we made an aluminum baffle to cover the pump and protect it from heat from the manifold. That worked pretty well until we installed a new fuel pump. Turns out those Mexican made fuel pumps are definitely inferior to the original type. I picked up an NOS one and installed and it and now it's fine again.  An electric fuel pump is usually the ultimate fix.  The earlier KF cars (1947-50) have this problem big time. I had a '48 Frazer and it was awful in the summer time.

[joefrazer]

My 50 Traveler and 54 Manhattan have never vapor locked (now that I've said that...), but my 53 will do it at the drop of a hat. Must be something to do with the hood design, lack of sufficient incoming air at slow speeds and just old age...and today's cheap gas. I'm very close to mounting an electric pump on my 53. If anyone does decide to go the electric pump route, mount it as close to the fuel tank as you can. You want the fuel pushed to the carb, not pulled.

[glen]

Hi,
My mechanic doesn`t think that vapor lock is the problem as the motor never had a chance to really heat up.
Also when I drove it on the highway for 45 min. heading home last weekend (temp. outside was around 65), I didn`t experience that problem (although I have in the past on highway drives in hot weather).
I`ll pass along your comments and let you know.

[boatingbill]

Make sure the gas cap is vented and the vent hole is not getting plugged. Air has to get into the tank to
displace the gas being pumped out.

[Fid]

Sounds like you're well familiar with vapor-lock - I wasn't sure. One of the things that caused a similar issue on my '51 was that mexico-made fuel pump was leaky on the bottom side. The car would leave puddles under it but I could never find the problem. When Weas came to look at it, I started it up and let it run. We looked under the hood and the fuel pump looked like a shower head it was spewing so  much fuel! I could never find the problem because when the engine was off, there was nothing leaking. The castings were not true so the surfaces did not line up and it spewed fuel and sucked air. The car acted like vapor-lock, even on 65° days.  Once we replaced that pump, the trouble was gone!
Doesn't quite sound like the same symptom though. Since it's fuel related, it may be sludge or build-up in the gas tank and clogging the line.  Car sits, fuel recedes/sloshes around, clog goes away. Anyway, keep us informed.

[superk226]

If the heat riser in the exhaust manifold is stuck and not opening all the way, it will cause the car to vapor lock even on a cool day.