See the video. Provide input please. Just put a new coil, condenser and points on. Dwell at 40 degrees (probably a bit high but couldn't find specs). It's a '54 235 in a 54 chevy.
Darn video didn't attach. Here's a description: When running normally and you 'stab' the throttle it falls flat, seems to really suck air for a second, and then comes up on RPM's. (this is in neutral but in gear, running around, it is the same). A steady, slow increase of the throttle results in a slow, steady increase in RPM's. Thoughts? Thanks, Scott
You guys probably can't see this video. I'm not sure how to make it so you can see it. I tried putting it up direct on here but it was rejected. Scott
Try putting the video on You tube . My truck had that stumble off idle for ages, fine tuning the timing / idle mixture / valve lash / plug gaps all helped. I pulled the carb, cleaned and cleaned it , put a kit in , did all of the above again . got it a little better . Tossed the carb (W-1) and fitted an old Zenith outta the junk heap in the shed ...... Goes Bloody Brilliant !!!
make shure your accelerator pump squirt comes in as soon as possible off idle if you have to adjust do so it may be getting air before fuel and going lean for a second
If you have a Rochester carb check the accelarator pump link hole. I've seen them wear so bad that the pump doesnt squirt till about 1/4 throttle.
bump your timing up dont go by the bb in the flywheel advance it enough to take out the stumble and not ping wont take much . 28 to 35 deg dwell new points .019 and used .016
had a terrible stumble with mine. Advanced the timing and bingo. I used a vacuum gauge to set it up pull as much vacuum as you can at idle and you will be good.
I had a Rochester B carb once that had the same symptoms. The accelerator pump spring was too small/weak and squirted too much gas. Replaced it with a longer spring from a spare carb and problem was solved. The RochB accelerator valve is vacuum operated, so the spring (or springs with more than one carb) needs to match the engine to work properly at part or wide open throttle. If the spring is too weak it will open too wide, too soon and flood the intake, giving too rich gas mixture and the engine hesitates/stumbles until it can recover. Check the timing and carb idle mix settings first, also check for vacuum leaks at the intake and vacuum advance and then check the carb.
Sounds like the accelerator pump isn't working. Take the air cleaner off and look inside the carb with it running. Goose the throttle and see if it squirts a stream of gas into the carb or not.
I've been dealing with the same issue on a GMC engine and after going thru about everything the fuel pump was not working right. Crack the fuel line at the carburetor and turn it over to see if you have fuel at the carb.Mine didn't, quick change out and it's running much better.
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