hard start only when hot

Ken Arms

Ken Arms

Well-known member
My 59ab doesn't start well when at temp. Engine starts cold instantly but once at driving temp (180) it will just crank and crank unless I feed it fuel with pedal. carb is rebuilt 97. engine is stock. fuel pump rebuilt and fuel flex line has a check valve. I thought about trying a carb riser. car is 12v and resister under dash has been removed, coil has built in resister. ignition is bubba built and runs super. Any suggestions welcome. thanks Ken
 
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Ken Arms said:
My 59ab doesn't start well when at temp. Engine starts cold instantly but once at driving temp (180) it will just crank and crank unless I feed it fuel with pedal. carb is rebuilt 97. engine is stock. fuel pump rebuilt and fuel flex line has a check valve. I thought about trying a carb riser. car is 12v and resister under dash has been removed, coil has built in resister. ignition is bubba built and runs super. Any suggestions welcome. thanks Ken
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Before attempting to start it next time when it is hot, remove the air filter and looking down the carburetor, pump the accelerator.
You should see two streams of fuel, first time you pump it.
Let us know what you witness and we will better equipped (knowledge) to go from there.
 
I would prefer a coil without a resistor and have the resistor ahead of the coil. Then you can have a bypass wire around the resistor to the coil when the engine is cranking. JMHO. I had this same problem years ago on a different brand. It was an instant cure for the hot/no start.
 
12 volt ignition systems had a starter solenoid with an ignition terminal specifically designed to bypass the resistor. When I had a 6 volt system on my car I was fortunate enough to come upon an aftermarket solution to bypass the resistor. That was for six volt system
 
I had the same problem on a 221 Ford with stromberg carbs and the coil was rebuilt and still had the hot hard start problem. I put 4 -5 gaskets under the carb and installed cupped core plugs in the exhaust cross over. Now starts instantly cold or hot. If you floor the accelerator when hot, does that make it start quicker? If so, carb is toooo hot. I note you are in Vermont and my solution of blocking the exhaust cross over will not work well at temps below 50degs F. I think heat is the root of your problem.
 
Thanks everyone, kube I did try pumping when hot with no improvement. Got my carb riser today so I will report back.
 
Ken Arms said:
up date, the carb riser has fixed my issue. Starts up with just a bump now when hot. Ken
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I suspect the ethanol fuel was the issue. It does not take well to enginge heat especially when you shut it off hot and try for a restart before it cools down.

I have a driver '47 that I experienced the same issues in. My ignition system was operating 100%. Skip rebuilt coil, 3rd Gen rebuilt distributor, new wires...

I insulated the gas line coming up from the firewall to the fuel pump. Then I installed an insulator carb riser. This soved my issue.

Ford did not do this. I wasn't alive 80 years ago so I can say for sure, however I doubt this was an issue at that time. We should not have to do this to ensure reliability. Ethanol fuel is by far one of the worst things you can run in an engine. Modern fuel injection will put up with it. Anything with a carburetor will not. Not my lawn and outdoor power equipment, antique tractors, old Ford. I keep pure gas on hand at my home for these types of applications. If I'm out on a long drive, I will inevitably have to fill up with enthanol gas. I hate it but have done all that I can to prevent issues.

A good friend of mine recently ran E85 in a flex fuel engine. One week of it caused an entire day in the shop for repairs to sensors. Ethanol is a fleecing.
 
again we are dealing with two totally different fuels . there is nothing wrong with either when used as they where designed older style fuels were designed to sit in open containers (ie carb bowls and vented fuel tanks] where as alcohol fuels [ethanol blends] are designed to be kept in enclosed systems [ie injection with pos/neg pressure vent tanks ] so when ethanol is left open it tends to evaporate off as it has a lower boiling point that is compensated by the pressure in the closed system so keeping it as cool as possible in paramount
 
Hi all,
i had the same issue on my 37 when i bought it. when was hot if i stop the engine i was obliged to pump several time with accelerator to run... I measured temp at fuel pum and carb and found more than 60°C.

I solved the problem by closing the two holes in intake manifold with 2 little metal sheets and adding a big seal (5mm) between the carb and the intake manifold.
 

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feufeu said:
Hi all,
i had the same issue on my 37 when i bought it. when was hot if i stop the engine i was obliged to pump several time with accelerator to run... I measured temp at fuel pum and carb and found more than 60°C.

I solved the problem by closing the two holes in intake manifold with 2 little metal sheets and adding a big seal (5mm) between the carb and the intake manifold.
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