Graham Paige misfiring.

[GrahamPaige29]

Hi guys. Finally got my 1929 Graham Paige model 612 running. She seems fine at idle but beyond low rpms wants to sputter and misfire.   According to my observations of markings on the bracket, my coil should be a model CR6912C but I have a generic 6 volt coil on there right now. Would the wrong coil cause these issues or is it most likely the distributer?  I took it apart and cleaned it and the springs seem to be ok. The point gap seems ok too. I can't figure out why she doesn't like higher rpms. 

[Old buicks 2]

Try a new condenser

[GrahamPaige29]

I have changed the I have changed out the condenser with no result. 

[Old buicks 2]

Are the high speed jets open in the carb?   Just a thought,  also try opening  the fuel adjusting valve 1/4 to 1/2 turn

 

[Bloo]

It is tough to guess without a 1929 Graham distributor to look at.

 

Some sets of points have a copper strap as well as a spring that take up the movement as the points open and close. Others only have the spring, no strap. One thing I have seen a couple of times is that a previous owner installed a set of points that had the copper strap, and left the spring off, leaving only the copper strap to act as a spring. The cars would idle, but as soon as you increased RPM the points would float. it's a long shot but worth a look I guess. The illustration is just to show a set that uses a copper strap and a removable spring, I don't know what that particular set in the picture fits, but most likely not a Graham.

 

The modern 6 volt coil should be fine. Make sure the polarity is correct. Older ones were sometimes different parts for positive vs negative ground. Today probably not, but if the Graham happens to be a positive ground car, be sure to hook the (-) side to power and the (+) to the distributor.

 

Too much timing advance in the distributor advance mechanism could do it. Also how do the points ground? Is the breaker plate bolted solid to the distributor in that model? If it's movable, there should be some sort of a ground inside, probably a wire.

 

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Edited March 11, 2021 by Bloo (see edit history)

[GrahamPaige29]

Hey Bloo.  Good ideas.  I will check those out later today.  If I can't see an apparent issue, this might be the first time I get a mechanic to look at the car.  I don't want to throw more money at the problem (buying more parts like another coil) and be disappointed they don't work again. I did drive her into the garage yesterday (10 feet).  Big day in my life haha.  But I would like to take her around the block without the stuttering and backfiring.  I'll take a bunch of photos of the distributer parts as well and maybe post them here....

[DFeeney]

Hello,  I am surprised that the general comment has not been on timing.  If your engine does not have external timing marks like many early engines ,make your own.   Bring the piston up to TDC on the compression stroke and stop.  Take a piece of metal coat hanger and make a pointer with one end attached to a bolt and the other end going over the crankshaft pulley.  Paint a mark on the pulley.  You now can see your static timing, you should also be able to see your spark advance,  Plus if you change anything you will be able to put it back to where it started.  Life is Good,

[Dave39MD]

All good suggestions. You might try pulling the choke out a little as you accelerate and see if it runs better. Like Old Buick said it may be lean past idle.  

 

Let us know.

 

Dave