I have a stock 235 chevy six and it runs inconsistantly. I ran it on saturday down some service roads at about 65 mph and it ran great. Pulled it into my friends shop and it started to cough and sputter and lurch in spurts of power instead of developing smooth power. Changed out the fuel filter and it still does the same thing, struggles to build rpm in neutral and in gear. I have done the new plugs, wires, cap, rotor, points, condenser and when I bought it 6 months ago the guy said he rebuilt the carb. The only idea I can think of is that the valves are out of adjustment, and/or the vacuum advance of the carb is not working. I think that the vacuum advace is supposed to turn the whole distributor (instead of the internals) but when I open up the throttle the distributor does not turn. Am I wrong here? Will the distributor turn from the vacuum advance when the motor is in neutral? Any one else have any ideas what might be wrong? The motor seems really strong and does not burn oil bad. I want to keep running the six, but it is giving me fits. Geno
On the stock 235 I had you could see the dist. moving. Accelerator pump working? Maybe the carb got some dirt in it?
My experience with a 235 (1959 model with solid lifters) was that if the rockers have too much slop in them it will run but clang and tick really badly. The only problem we ran into with the engine running rough and stalling was when the rockers were too tight. And I can't think of any way that yours would tighten up on you from driving. I don't know if the dizzy is supposed to twist in neutral, but I can't see why it wouldn't. Can you turn it with your hand? Maybe something is hung up in it. Maybe the line has a crack or leak somewhere. Check all your vacuum lines. Which carb is on it?
The distributor should turn when you increse RPM's, replace your Vacuum advance unit, you can find new ones on Ebay. My 51 Chevy ran the same way just before the fuel pump shit the bed completely. Later 230/250 CI Chevy 6 pump is the same. also, check for possible vaccum leaks at intake manifold & carb base by spraying area with carb clean & lisetenig for change in rpms while idling. The bad Vac. advance could be a source of a vacuum leak also. Hope this helps. Billy
While we're on the topic... sorta... I've got a '53 235 that runs beautifully 99% of the time. The only time it doesn't, is after a long period of deceleration or say, going down a hill with my foot off the gas. When the car idles after that, it misses like crazy until you get back to cruising, then it runs as smooth as can be again. What's up with that? Derrick
Twist your dist each way and rev to see if it runs smooth in either direction. The advance from carb to dist starts at 500rpm and up while throttle/load is applied to the motor. If you adjust the timing, plug the vacuum line from the carb after disconnecting it. The valves being to tight as Deyo stated is true and harmful. If they're not ticking, they're too tight, and that is bad! If its been this way for a while you may have to replace your valves. Lastly make sure your carb is correct since your motor is having troubles on throttle. Good luck. j
Yeah I am going to have to tear through the carb I think. Just spent the last hour in the driveway with a flash light fighting with the old fuel pump and replaced it. Still made no difference. Sure hope that the carb has an easy to fix problem. Geno
53- are you sure it isn't bucking from being in too high of a gear? Geno- which carb is it, if it is a Carter 1bbl (YF is the model of the one on Munson's truck) it is easy as hell to rebuild. The hard part is figuring out if the last guy that rebuilt it had the appropriate needle and seat assmebly as there are 2 options. NAPA has the kits, they are about $20 or so.
From what you described, your vaccum advance is not working. The dist. should move/rotate as engine RPM's rise. If it doesn't, you have no advance to your timing. This will cause the symptoms you describe. Proceed accordingly... r
you can get the vac advance unit from a variety of sources new. YOu don't have to go to ebay. I think they run around $40
It doesn't miss when I'm slowing down, it's once I've stopped. it starts missing during the idle and through acceleration for a little bit after, then just goes away until next time. Only happens when the engine's warmed up good.
Has any one ever ran one of the HEI units from Langdon's Stovebolt? I was thinking that if I needed a vac advance, it might be worth it to purchase the HEI Dist. for the 235. Geno
The Jalopy Journal
