First Start Issues

[bil1024]

Running carbed 302 with MSD distributor and ignition box. Seems I am getting a dull spark at plugs, coil spark looks fine. The distributor is locked out no weights or springs . Could I have a bad coil or distributor faulty ?

[ayellow56]

First I'd look at input coil voltage, 12,6 or better, then I'd check your plug wire resistance. Your chassis to engine ground cable should also be checked just to be sure. Good luck. Steve.

[Alphamacaroon]

I second the engine ground comment.

Also, I’m not an ignition expert by any means (I’ve only used MSD once and it was years ago), but doesn’t the MSD act a bit differently than a normal ignition system? Doesn’t it fire multiple smaller pulses rather than one large one? Could that be what you’re seeing and maybe it’s a red herring for another issue?

[Old Timer]

Check voltages first, while cranking the engine.
Might look for cracks in the distributor cap? Other abnormalities?
There has been failures with the MSD boxes lately. Is it easy to bypass the box?