Help 454 wont start just diesels

[Lash61]

I started my winnie 3 times today with no problem 4th time no start. It diesels a bunch when I stop cranking the engine. It spews unburnt fuel from the carb. The only thing I hear different is a rattling in the distributor when I turn the key to on. How can this be? Any Ideas?

[gadgetman]

Pull the distributor cap and take a look, maybe you have a rotor that has come loose or a gear that has stripped and the shaft is now out of time.  Its likely one of the 2.

[GONMAD]

Also look at the advance weight assy. Depending on the mileage you might have need for an aftermarket Advance Curve Kit. As the stock advance for an HEI (if thats what you have)is only 4.5 degrees mechanical it kind of leaves you flat for power Use one heavy spring & one medium spring & reset the timing to 8 to 10 degrees. You'll have your timing at no more than 34 degrees TOTAL for a good big block. If this is NOT your problem look at the timing chain to effect it in this fashion also. Hope for the aforementioned remedy, it's cheaper!
Hope this helped  C YA! GONMAD

[Lash61]

Thanks for the tips. Problem is solved. It turned out to be the electronic spark module. Somehow in its old age it grounded out to the distributor plate and died. Heres the clue, it caused the plate to take the firing charge and caused it to vibrate and rattle. Just glad it wasn't the timing chain.