1923 Buick 4-39 Engine problem

I have recently got my 1923-4-39 running and on the road (see previous posts and video) and have come across an issue that i'd like the clubs advice on. my Buick has been running well for the past few months, I run her every weekend with many smiles and thumbs up as I drive down PCH. Yesterday, when I fired her up she ran well for about 2 minutes, then sputtered down to running on 3 cylindres. I let her sit for a few minutes, fired her up again, and the same thing happened. I continued this cycle all day- hoping that she would somehow "fix herself". Well she hasn't.

It is my #2 cylinder each time- runs smooth, craps out after about 2 minutes, let her sit fires up smooth- craps out to 3 cylinders.

I am by no means a mechanic by any stretch of the imagination, a tinkerer at best.

Changed the #2 plug, changed the #2 wires.

What do you think it is, and where should I start?

I'll keep the forum updated.

Dave,

First, just do one thing at a time to find the problem and try the easy to fix items first. You have already eliminated bad wire or plug, so I would next check for a crack or carbon deposits in the distributor cap. You can use WD-40 to clean it up. Next, you could do a compression test to see if #2 is lower than the rest. That would mean either a burnt valve or worn rings causing low compression.

I will agree with Mark on doing only one thing at a time.

My rule for fixing something is to FIX THE OBVIOUS FIRST!.

Got burned once by not following this rule and have never violated it since. I spent a lot of time trying to diagnose a no start problem years ago and it turned out to be a damaged wire that I did not think was the problem.

The fact that it will run on 4 cylinders OK for a while suggests that nothing major is wrong since it will run OK. You have a crazy intermittent going on, finding it will be the challenge.

Hard to diagnose remote control. Maybe a #2 exhaust valve hanging up? Put some oil in the #2 valve retainer ad see what happens.

It will be interesting to find out what the problem is - be sure to post the solution

Agree with all that has been said.

When the issue with #2 starts, pull the wire at the plug at #2, with the engine still running, and hook it to a known good plug and check for good hot spark. This will tell you to look at ignition or to look at the valves/compression.

I've seen bad caps do what you have with a hairline crack that opens and shuts due to temperature and when open gave that cylinder a grounding path for the spark.

Also, I once had my engine die for no good reason, like someone pulled the coil wire going down the road. And it kept doing it. Drove me nuts. The issue was a broken ballast resistor wire that would work fine at the first cold start, then get hot and break the circuit, then cool and come back together and work. And then start the cycle all over again. Finally found it working by the side of the road as it got dark and saw the little devil sparking as I was cranking.

Also had the bake-O-lite (?) rubbing block on the points finger crack and fall off due to age causing the points to not open. Dead-on-the-road then too. Took a while to find that one. Found it when checking for gap, there was none. Then thought, how can that be, where/how did it go away? How could I have been running with no gap? Answer was laying on the plate of the distributor, that little piece of bake-o-lite. I had an old worn set of points that had been bouncing around under my seat since before Coolidge was in office. Found them, cleaned them up with what tools I had, eyeballed the gap and away we went.

Excellent suggestions- I will get to work on them starting Saturday. I will keep the group posted.

Thanks, Dave

I would check the point gap. My 15 Buick was doing about the same as yours years ago. After some sorting around with plugs, I took the cap off and found that the point gap had closed enough that on three of the lobes it was hitting on and one, worn just a few thousands difference that the others, the points did not quite open enough. I re-set them and it has been fine for many miles since. Dandy Dave.

I have NOS ignition parts for your car if you need them 402-359-5762 926-6909 or tsvanmeet@gmail.com

Tom