1969 Coupe DeVille 472 engine runs rough until it warms up

[cadillacmike68]

TJ, I think mine are R44XLS as well (but I'm not home to verify).

[R Schroeder]

All this talk about the plugs, but I don't believe I read anything about the points.

If they are not set right, the coil could be producing a weak spark.
The dwell is needed for the coil to have enough time to build up its correct charge. If the dwell is wrong , your going to have a weak spark. Then you will get fouled plugs.
If points are to close , you will burn them. Timing also will be off.
Set dwell then timing. 30 degree dwell on this car.
Plugs are gaped at .035 . One site I looked at called for R44N plugs.
To me it looks like you either have a weak burn on the spark, or you are using some oil in that car.
But there can be other problems too.
Roy

["Cadillac Kid" Greg Surfas 15364]

Roy,
FROM THE SYMPTOMS of running rough when cold and ok when warmed up I would deduct that the spark being "hot" enough is not the issue.  When the engine warms up and  the cylinder pressures get higher (due to increased compression) is when a weak spark would show up.  What is apparent (to me at least) in the fouled plugs is probably a combination of oil fouling due to worn rings and/or valve seals, and an "under driven" vehicle that needs more exercise.
Greg Surfas

[R Schroeder]

Greg, I would agree with you that this car is probably TIRED IRON , and has oil problems.
Just tossing out other ideas. It probably isn't the cause of the problem in this engine.
Probably would be nice if owner would give mileage ,and the type of driving they do in the beginning of these types of postings.
Roy

[TJ Hopland]

I did not go back and read every reply in this thread but fairly early there was mention of electronic ignition and plug problems so I think that is how we ended up coming back to spark plugs and why there was no talk about points.   Just recently I asked about the type of driving and we got a reply that most of us think is a a little on the short trip side so we were thinking before condemning the engine condition that it would be worth seeing what the plugs look like after a longer trip. 

[cadillacmike68]

He did mention electronic ignition on page 1 and how it devoured his plugs!

I would Rip it out and put in a proper Delco P&C ignition.