Both of my Buick Skylarks (69 and 71) 350s hesitated until the timing was advanced 5 or 6 degrees past the factory setting. A similar hesitation was caused be a bad vacuum advance on the 69. Remember OK4550’s suggestion not to get carried away with advancing the timing.
Make sure the idle passage in the carb is clean.
If possible remove the idle mixture screw and spray carb cleaner in there with an extension tube.
ok4450: Both idle mixture screws were just slightly over 2 turns out. No EGR. If by “reading” the plugs, you mean checking the color and/or gap, then yes to both. The gaps were all right on, and the color was neither a jet black nor smokey white. It was a brownish color…
Stock points ignition? As Tester said, that little wire pigtail that connects to the points…How many years has THAT been in there?
What they’re getting at in regards to that wire is that it moves with the vacuum advance plate.
Bend a paper clip enough back and forth and things start going wrong.
What about the condenser? This little widget usually gets overlooked and can cause all kinds of grief.
Fixed it! I took a closer look at the distributor, and the inside of the cap looks like it had been tearing itself apart little by little. The metal on the inside was burnt looking and had little chunks of plastic stuck to them. Also, the inner center of the cap was very unevenly worn, so I replaced the cap and rotor, and all the stutters went away! Did a tune-up (timing, dwell, idle mixture, idle setting) and she runs like new. Thanks for all the help everybody!
If you did not change the condenser I would highly recommend doing so. There is no way of testing these things and failure can be at once and permanent or it may come and go erratically.
Many years ago a lowly condenser left me stranded in a small town in the OK Panhandle on a holiday weekend while I was riding a 40 year old motorcycle. The condenser on that one was only a year or so old.
Very small town, the weekend, nothing open, and I was pretty much skeerewed. A gentleman who ran a quick shop store there knew someone who owned an old deserted shop down the street and he was gracious enough to call the guy up to see if he had anything.
The elderly man who owned the shop said he had several old 40s and 50s era motors sitting around rusting away and I could help myself to anything that would help me out.
Luckily there was an old flathead motor sitting there and I pirated the condenser out of that. Since it would not fit the motorcycle I clamped the condenser tab to the frame and ran an additional wire to the coil. Crude, but it provided a spark and got the last 200 miles to where I was going.
Nice car you have. My sister had a ‘64 GTO (389), my cousin had a’ 65 LeMans, and a good friend had a '64 Le Mans with the 326. The 326 was a vastly underrated engine and a good solid performer.