Hi, first post (busy working on my 57 Studebaker Golden Hawk last 10 years, Model-A before that). I bought my dad's '53 Buick Super V8 convertible years ago, which we've had since 1974, and is STILL up at the farm where 95yr old dad STILL has driven it to church on Sundays til the past year of Covid. So all I've ever done is occasionally change some fluids and try to keep the power windows working over the years. 🙂 In all those years, it has never stalled (except parade vapor lock). 95,000 original miles, engine partially rebuilt 30 years ago, otherwise original but for 50 yr old paint and upholstery. (and occasional tune-ups, new starter, MC, all over a decade ago or more)
Problem: last weekend, I went up to the farm and took it out for the usual 4 mile round-trip just to keep things lubricated jaunt. I got 2 miles down the road, purring like usual, when all of a sudden the RPMs dropped off, but then (maybe went from 55mph to 40? never thought to look) it came back up to speed. This continued all the way home ; imagine an old police siren cycling up and down, that was my RPM. When I got to the farm driveway, it died completely, but perhaps because i slowed for the turn. Enough momentum to coast all the way down the driveway and 1/2 way into the old car shed. Thought "shoot, how am I and dad going to push this in now? Without denting the bumper?". Put it in Park, pressed the accelerator (start) and roared to life. Revved it up and down as high as I dared, smooth as silk for 15 minutes. But now I don't dare drive it out on the highway again, and really get stuck out there and no way to get towed home!
i think it is completely coincidental, NEVER an electrical issue in the 50 years we've owned it, but I DID turn the lights on (getting dusk) slightly before the cycling started. I turned them off, "just in case", and didn't affect anything. Again, all lights work, no gauges are burned out, no shorts...
I put an NOS Delco fuel pump in .... probably 15 years ago now (hoping to help with the vapor-lock stalling; it did not). But less than a 1000 miles on it since then I'd bet. Not convinced a fuel pump would cycle like that anyway.
Carb was maybe rebuilt about 20-25 years ago (mom and dad still driving it all over Minnesota with Alexandria Car Club) , but I can't think of ANYTHING that would make it cycle like that, vs spitting and dying like a bad coil or condensor or other electrical would do. Or clogged carb jets.
Oh, also put in fresh premium non-oxy fuel a few weeks ago with Stabil and SeaFoam (and had driven it several miles after that without issue).
Dad's health is starting to fail more quickly, and I need to be able to drive the Super to Mpls/St.Paul area (~3hrs) with confidence when that sad day comes (or after farm auction at least).
Any ideas what would cause engine RPM cycling like that? Was going to rebuild the carb "just in case", as I can't think of anything else TO do with it. 😞
Thanks! Hope to join the club and restore the car to CITY driving capability someday when this Golden Hawk is FINALLY done. (and rebuild the DynaFlow, instead of putting in 3qts of Dexron every spring! only leaks in the winter...)
Barry Rosell Lake Elmo, MN