Acceleration hitch

[SoCalCoupe]

Car is a '41 Coupe w/ 221 engine, helmet distributor, Skip Haney coil, Tubman condenser, stock fuel pump, and a Eddie Meyer intake w/ dual Stomberg 81s.


It was running really strong a couple of years ago but slowly degraded with less power and a pronounced stumble in acceleration. I was thinking timing so I re-timed it on the KR Wilson timing tool and that was a big improvement. No more stumble under normal acceleration.


But I still have a hitch under heavy acceleration. Not a stumble, but a single momentary hitch like the ignition momentarily cuts out. Of course it could be a fuel problem too.


Anyone else had symptoms like this they were able to fix? Rather than spend hours going through all the possibilities, it would be nice to cut to the chase.


There are several possibilities I can think of:
1. ignition switch contacts
2. low float level
3. water in fuel
4. need more timing advance above specification
5. low fuel pump flow


I had a year-old tank of gas in it back in March because the car was out of commission for a year with the rear end in pieces. The first time I drove it, it was fine, since then I've run the tank down to half full three times and topped it off with fresh gas.


I have an electric fuel pump I use for priming and a fuel pressure regulator with a gauge just before the carburetors. The easiest thing to do would be to check the fuel pressure at the outlet of the stock pump for the 1000n't time, it's always fine. I could then drive the car with the priming pump running to see if that makes a difference. That would point to or rule out the mechanical pump but I don't really think that's it. I was driving it around yesterday but just forgot to try this.


That still leaves four options.


Like I said, just looking for experience that would help me shorten this process.