Engine stumbles on acceleration

I installed the original cap, set the timing with the Nu Rex wrench and then swapped the old cap for the modern cap. Do you see anything wrong with doing it that way?
 
It sounds logical but I dont' know if the spark plug locations in the modern cap are in the same locations. If the modern cap has different clocking relative to the tab that engages the distributor body, your timing will be different. Can you check it with a timing light? I forget if you said that you had done that.
 
arnhemmer said:
If you a vacuum wiper motor check it and the hose for possible leaks.
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Get it started and running at the lowest idle speed and spray carb. cleaner around the manifold to block areas and if you get an increase in RPM chances are a intake gasket leak. Quick acceleration, not only from idle, has to start with a rich mixture and intake leaks will cause a lean mixture.

John
 
The vacuum wiper port on the manifold is plugged, temporarily, while I rebuild the wiper motor. I did change the manifold gaskets some time back. I will try spraying the carb cleaner on the manifold.
Thanks for the ideas.
 
I had another idea on the timing if you are having trouble setting up a timing light. I know it is a pain the first time because there is no mark on the pulley or pointer to go by.
Set the timing using the NuRex wrench and the original style cap, then keep the original style cap in place when you run it and see if that fixes the hesitation. Then you know it is a difference in the two distributor caps.
 
Yesterday I changed the plug wires from resistor to solid core. It made a significant difference in the way it ran. Cleared the stumbling 90%. I compared the old distributor cap with the new modern cap. They are virtually identical. I checked for air leaks around the intake manifold. That’s all good. I used the unlit propane torch method. I did put an extension on the carb intake to make sure I wasn’t sucking any propane into the carb. Today I’m going to remove the fuel filter and check the timing with a timing light. I did a vacuum gauge check and the gauge reads between 18-21 inches of vacuum. A little bouncy! I still can’t get it to idle low enough. That causes gear shifting problems. A low enough idle causes it to want to die when coming to a stop. More testing to come. I may have to take the plunge and buy a new carb.
 
I changed the fuel line to remove the filter. No change in the way it runs. I made a timing pointer (photo attached) to check the timing. Timing was right on. Looks like it's time to buy a another carb!
 

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So, i completed all the things discussed in the above posts except the carb replacement.
The car runs 90% better than it did before. No more backfiring. The two things that made the biggest difference were verifying the timing was correct and changing from reistor plug wires to solid core wires.
The addition of the timing pointer was a big help. I cut a small notch in the crank pulley with my Dremel grinder and put some silver paint on it.
See attached photo
 

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Neshkoro said:
Marshall,
Thanks for the PM. I'll remove the fuel filter and do as you suggested. I wont be able to get back to the for a couple of weeks. As soon as I do, I'll reply with the results. Thanks so much.
Bill
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Marshall V. Daut said:
Only any fuel filter between the sediment bowl and carb, not the pencil filter inside the gas tank or the round filter screen inside the sediment bowl. See that the sediment bowl screen is clean. Also remove any external air filter on the back of the carb to test if that's affecting the acceleration by choking fresh air intake.
M.
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700rpm said:
I have high respect for Mr. Daut, but my experience re: pencil filters vs inline filters is just opposite of his. :) I ageee on the sediment bowl advice.
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So let me get this straight. Marshall recommends to remove "only any fuel filter between the sediment bowl and carb" but leave the pencil filter in (to which I agree) but you are saying the opposite, to remove the pencil filter and put an aftermarket filter between the sediment bowl and carb?
 
I tried that. It didn't seem to help much. The A runs pretty good now. As good as you would expect a 90 year old car to run!!!
Thank you all for all your help.
Motor on!
 
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