Hello Gentlemen . I have a 67 rs ss thats a pita!! She will not start on a regular basis . I have had her at performance shops that specialize in these cars lmao. They charge my battery and then say all fixed . when I go back and tell them they didnt fix the strating issue that I paid a small fortune for they tell me its another issue .I brought it in explain the situation in GREAT detail !! OK so new battery new starter new wires the old ones were spliced numerous times on each wire holy cow !! alternator re and re;d . new plugs and she wil start then I go for a tour and if I turn her off she will NOT restart for hours . There is a heat shield on the starter so saturation should not be an issue . I have had her for years and NO ONE is honest enough to fix her properly!! I have spent a pretty penny for no results VERY VERY frustrated here PLEASE HELP summer is here and I want to take her out but dont want to get stranded as usual

 

Is it cranks but won't start or no crank?

 

Check the main connector at the firewall. The connector is held in place by plastic tabs that are probably gone due to age. This loose connection intermittent no starts. First time it happened to me I had the car towed home cause I had no tools. When he dropped it off the flat bed it started right up. I pack some tools in the trunk and the next time it happened it only took me 5 minutes to track it down. You just need it when its doing it. I wire tied the large connector together and put a whole new harness on my wish list.

This is the large connector under brake master cylinder.

Note: this is just what happened to me. Step one when its a no starts is to figure if its loosing spark or fuel.