maineolds

My 1949 Olds 88 with the original 303 has a distributor issue. Ive mentioned it in previous posts but still struggling a bit with the solution. Here's the situation:
The rotor fails to clock accurately from one spot to the other. In other words, as the rotor rotates, it sometimes hangs up or fails to spring to the next point on the distributor cap. That means after a bit, the rotor no longer makes good contact with the cap points leading to each spark plug. I've never seen this happen before and so im at a bit of a loss. I've replaced the cap, rotor, even the ignition system to Pertronix ignitor before I found the real issue. This problem has persisted no matter what cap, rotor or ignition system I use. I've used OEM vintage parts and good quality Napa replacement parts. Im absolutely confident the issue is deeper than the surface of the distributor. It's in what ever mechanism causes the rotor to rotate. I've oiled the little felt pad under the rotor so the distributor should be lubricated. Am I missing something? After 71 years of service I'm wondering if the distributor as a unit is just worn out. Are there replacements for the early 303? Searching Summit and other parts houses shows plenty of parts to rebuild and improve the guts of the distributor, but no drop in replacements. Im open to any and all ideas!

oldcutlass

There is a pin that holds the distributor gear in place. Is it sheared?

maineolds

nope. Still there. It’s not spinning freely, just a little more sloppy than it should be. Imagine a clock face and a minute hand that ticked from minute to minute. After enough rotations, the small accuracy shortcomings from minute to minute add up to make the clock inaccurate

Sugar Bear

Hopefully we get input from someone very familiar with that generation of engines. On later motors the distributor is driven by the camshaft which is driven by the timing gears so, the problem could be in the timing chain/gear on the camshaft front, the gear on the camshaft back, the gear on the distributor bottom, the pin retaining the distributor bottom gear as mentioned, a broken distributor shaft or stuck/sticking advance weights in the distributor.

Start with the easy things first like the pin old cutlass suggested, the weights in the distributor. You could pull a valve cover and see if the skipping correlates with the valvetrain, then it's in the timing gear set.

Good luck and keep us posted!

oldcutlass

If you grip the rotor and turn it both ways does it stop or keep turning?

maineolds

it stops most times at the appropriate place, but some times I can get it to advance by a click with a little wiggle room. This is very hard to describe. I’ll try to take a video next time it acts up.
the car runs flawlessly for many miles, then starts to stumble. Usually after I shut down the engine and start it again. That’s when I know to pop the distributor cap, rotate the rotor a bit till it finds its home and clicks into place. Then we’re good again for a while.
I don’t know how the mechanics of a distributor work, but I’d guess the problem is with the stuck/sticking advance weights in the distributor.

maineolds

If all else fails, I'll send in the original to https://mondelloperformance.com he's an Olds legend. I spoke to them today and they offered to rebuild it. Let's hope it docent come to that.

oldcutlass

I wouldn't, Lynn can screw up a ball bearing with a feather. He's a legend alright, there are many nightmare posts on here pertaining to dealings with him and his company.

zzcruzin

Sounds like it might need a new bushing and a good cleaning and lube.

maineolds

wow! Never heard that before. I certainly keep your concerns in mind. Anyone else able to chime in with personal experience?

redoldsman

There are lots of threads on here about this issue. Joe Mondello was not involved with Mondello Performance in Paso Robles, CA. Stay as far away from this company as possible. Joe Mondello Racing is located in Crossville, TN and is run by Joe's widow. Here is the link. mondello.com - Builds and Tech Articles I doubt they will be much help on your distributor.

maineolds

that was not the company I sent a link to. The link I sent was for the company in Paso Robles.

Charlie Jones

I got my 394 distributor rebuilt by Everyday Performance in CT .
They did a good job . And it works excellent .
https://www.everyday-performance.com/

maineolds

hey that’s a great lead! Thank you!

Tedd Thompson

Does your vacuum advance hold a vacuum if you suck on it? Could be the degraded rubber in it have a leak and keeps it from advancing at times? Does it always malfunction on acceleration but idles ok at low RPM. Just a thought... Tedd

PS... Any distributor from 49- 56 should work and 56 is the preferred because of the windowed adjustment for the points. You might check with Ozzie and his Hollander exchange bible incase my memory is lacking....Tedd

maineolds

good thoughts Tedd. Unfortunately it doesn’t seem to be that. The vacuum advance is fed by a copper pipe. No leaks present. The malfunction isn’t speed related. It’s start cycle related. Some starts have no affect, other starts and you know immediately that something isn’t right. That something gets worse the longer your drive it till the cap is removed snd the rotor is clocked into its proper position again. Usually just a fraction of an inch, but it’s enough.

Sugar Bear

Sticking advance weights???

zzcruzin

X2 on this possibility.

rocketraider

I'd be inclined to send it off for a rebuild and having it set up on a distributor machine. That will uncover and correct any problems.

If a 56 distributor will work I'd for sure look into that. The availability of and ease of setting points would be a big plus, and undetectable unless you knew what you were looking at. DK how compatible it is with 6V electrics.

Charlie Jones

It will work OK , if you swap the condenser for the '49 condenser , so it matches up with the coil .

redoldsman

The 56 distributor is a huge improvement. I put on in my 54 because I got so tired of taking the distributor out to accurately set the points on the 54 distributor. You can pop a set of points and condenser in it and it will usually start up with points right out of the box. Then you can take an allen wrench and set them exactly at 30°. I consider it a great improvement.

maineolds

Im no expert, but after a thorough exam of the distributor removed from the vehicle it looks like all is well enough. It’s holding vacuum. I bet this is simply a case of it being 71 years old and in need of a good servicing and a little more expert testing.
I had a starter rebuilt by these guys https://www.northstarautoelectric.com/ and they were excellent to work with. Turns out they do distributor service too. I spoke with them today and will be sending it out for service to figure out what’s up with the fickle advance. Thanks for all the help and advice. I’ll keep everyone posted on the ultimate solution.

OLDSter Ralph

Try these people !

Look for a 56 distributor and have it checked out by the people Charlie suggested ! I am suspecting the bushings in the distributor body are worn badly. The drive gear on the distributor could also be severely worn.

redoldsman

Interesting. I bought my 56 distributor on ebay for $30 plus shipping. The guy sold it as a rebuildable core. When I got it the shaft would not even turn. I soaked it with PB Blaster for a couple days and then put it in a vise and took a pipe wrench on the drive gear and gradually broke it loose. I then kept lubing it and turning it until I could spin it with my fingers. I then cleaned it up and put a new vacuum advance, points and condenser and a new cap and it works great. It was one of those things I took a chance on and it paid off.