Technical Chevy 235 Distributor questions

Hey y’all, so been having a few strange things here and there happen with the 54’ bel air. To my knowledge it’s mostly stock, aside from radiator and a few other suspension things. Lately she’s been bucking on me while on the freeway (it’s the same big turn every time, I let off the gas while coasting around a large bend, and then when I go to get back on the gas she’s bucks on me, before finally catching) and it’ll die occasionally when I coast up to a stop, unless I throw it in neutral pretty far back. I got to poking around, went through the ignition system with new points, condenser, coil, and new resistor but the problem persists. For shits and gigs I hooked a hand pump up today to the steel line going from the carb to the dizzy (left it hooked and the dizzy and disconnected at carb and hooked up hand pump there) went to pump it to test vacuum and it held nothing. So first thought, vac advance isn’t working. Then I started down to rabbit hole of how to replace it, and it brought me here. Does the distributor need to come out? Checked my shop manual and searched thread topics, but found no concrete answer. So anyone out there got a little walk through, or want to hold my hand on this one? I’ll post a photo I took of it today

 

The way it's made you have to pull the distributor.

 

I had to look to be sure but apparently so.
Take something and mark a reference point on the side of the motor as to where #1 plug wire in the cap sits or for that matter the plug wire that you can get the best reference mark on. Then take the cap of and bump the motor over so the rotor is at a spot where you can make a mark to line it back up. I'd also check the orientation of the distributor housing. Then take the distributor out and swap the advance. The tab the bolt goes through to the block should have a 0 mark and some degree marks center the 0 spot on the hold down bolt and turn the distributor body to line it's orientation up before you tighten the clamp. I'd set the timing with the light by turning the distributor housing in the advance clamp and then you can fine tune it by moving the advance plate a mark or two if you feel the need. Back in the day that was how you adjusted the timing to compensate for crappy gas.

 

The vacuum advance is not causing the problem....

 

move chased my tail for weeks and short getting into the fuel system I’m not sure where else to go with this. So any Insight on what it may be is seriously appreciated!

 

ive been having simular problems . new fuel pump , no help . new e dist.., no change . placed a elect fuel pump before fuel pump , problem solved . im not sure if its caused by todays fuel , but either way ,i can leave the drive and return !!

 

also new tank/lines before the start . no new carb still , but problem solved .im planning on re -installing stock dist. with real points condencer , and fit/ look !! hamb friendly ???

 

Pulled one off a couple weeks ago.
Have to remove the dizzy.
Listen to mr48 Chevy and make reference marks.
Take pics with your phone.
Squirrel is usually about 99.99% accurate.
Have you checked the carb?
My Ford advance wasn’t working.
Didn’t skip or stall. Just felt slower on accelerating or going up hills.

 

Timing pointer on the bell housing and ball is on the flywheel and you can see it above the starter in a hole. I always paint the flywheel marks with white paint when I have the lower bell housing cover off..

 

Good idea
Thanks

 

Try replacing the coil,when the oil in it gets low they can act funny when turning and stopping.

 

Coil was replaced a few days ago. I went through the ignition system front to back

 

The two times my 59 truck did stuff like that, 40+ years ago...once was the wire from the distributor to the coil, was loose, the other time was the fuel line under the cab, was cracked and sucking air.

There are a bunch of weird things that can happen. Loose carb screws...holding the main body to the base....loose contacts in the ignition switch...loose motor mounts letting things move around...the list is endless.

 

Have you looked into the float level in the carb.

 

Hmm...water will roll around on the bottom of a float bowl or tank and can get sucked in, under certain circumstances....like a big turn in the road.

 

this was my next endeavor probably. Problem is, my knowledge of these old cars is slim to none. I’m learning as I go. Prior to owning this 54 I had never even pulled a spark plug, so needless to say I’m slamming my head into a wall every time something pops up. Gotta love these old cars

 

^^^^^^^^^^^^^

 

there's one way to learn...get in there and do it! You'll make mistakes, but you'll fix them, too.

 

I suppose as long as I don’t do any reversible damage it’ll all be fine. Only thing that’ll get seriously damaged will be my pride and fighting spirit (hopefully) so, let me ask, if this were your car, what’s the next troubleshoot. Ignition system is up to spec, vacuum holds steady on intake manifold, and timing is on spec. What’s a young man to do next?

 

Check your mixture, sounds like it is off. Adjust while the engine is running, find the spot which gives you the highest RPM (it will not run well either side of this point), and then go for a drive.

 

would this be best done with a tach hooked to the coil? Or with a vacuum gauge. I picked up a vac gauge the other day and so far just checked that manifold vac was holding steady, but I also want to tune the carb with it. If vac gauge is the best route for that, would I hook it up to the carb and play with the air fuel mix screw until it achieves best vacuum? And where exactly on the carb should the gauge go? Again sorry for the “day one knowledge questions” but I’m still learning here

 

Sounds like a vacuum leak somewhere, spray some engine start around the carb base and manifold gaskets.. Beware of sparks while you're doing it tho..

 

Either will work, but I have always done it "by ear". Any where after the butterfly in the carb is ok, I think there is a threaded port on the 235 inlet manifold between the carb and the back of the motor.

 

Thought this too, since the intake was off a few months back and had headers put on. I tried a bit with some WD40 yesterday, but didn’t notice anything major in change of engine sound. Might revisit it again with some butane and a bit of rubber hose at the end of my torch head

 

Intake installed with the correct alignment rings?

 

I seem to recall none of those being removed when the headers got put on. A buddy helped me with that one, so luckily I had someone who had done that type of thing before hold my hand through that one. There was a bit of grinding on the headers to get everything to fit well though

 

The intake uses 3 thin metal alignment rings.
Just spitballing
Wanted to make sure ya still had em.

 

Yea one of those bad boys popped out when we pulled the stock exhaust and intake to put on the headers, but it went back in the right place, and we used a new intake/exhaust gasket I got off chevs of the 40s beforehand. Before work this morning I’m going onto fire her up and let it idle to operating temp and go back to spraying around some wd40 to try that again. Vac leak would make sense as the bucking tends to happen when I’m off the gas on the freeway going through a roundabout, and when I get back on it she bucks. So vacuum would be at its highest when off throttle, and sucking air during that time causing a lean mixture, I think at least

 

Although, let me offer this little tidbit. I did have a vac gauge hooked to the wiper port on my intake yesterday and it held at 20 steady. Would a leak somewhere in the intake manifold cause it to drop or act erratic?

 

A steady 20 sounds great.
How does it read when you give it throttle?