Engine misses, stumbles

[joltesvig]

Standard 4 banger engine in my 31 coupe. The plugs look good and so do the points. When it warms up a little it starts missing /stumbling when I step on it a little. The manifold vacuum tube is not loose or leaking. It starts and idles fine. Maybe needs a new condenser...is there an easy way to know other just replacing it? Any other ideas? Worried it's going to die out completely on the road one day!

 

[RawhideKid]

How old is the distributor body and rotor? If you have one of the Red distributor bodies they are known for jumping spark between 1&2 and between 3&4 internally, so it could be the problem.

Where is the GAV set? If it is more than a full turn open it can cause too much gas into the engine, which can cause a coughing.

 

[Tom Wesenberg]

Hold the coil wire 1/2" from a head nut, and you should get a hot blue spark. If you do, then the cap or rotor could be bad as just stated.

If the spark is wimpy yellow, then try a new condenser. If that doesn't help, then try another coil.