Just purchased a 64 deville and replaced the starter on it. I was/am still having issues when it would run for a while and I would shut the car off then trying to restart the car and it would struggle to start. I would act as if the battery was bad but I also replaced it at the same time as the starter. I’m not sure if it’s heat soaked or the wire from the starter to the battery is bad (the wire looks fairly new) or could it be that the car is running rich which it is. Cold starts it’s fine fires right up every time. Any suggestions?
i can finally chime in and say,,i had same problem,, thought it was starter, but turns out, that wasnt it,,,so replaced starter,, then the ignition wires burned up at the key, melted the connection,,, did the jumper process as noted in post above to start car,, car would start just fine cold,, but if i went out for a ride, turned off car, then tried to start again, immediately, it would not turn over.. after about 10 or 15 minutes, it would start just fine,,,cleaned all the grounds straps of globs of gunk,, replaced battery cables, I noticed that my ignition wires were running right next to the exhaust manifold,, like millimeters from touching, so i thought they may be getting over heated and affecting the starter power,, I got some of that heat resistant tape wrap, wrapped those wires, then found a little wire holder clip on the body where those wires were supposed to be clipped to, and that piece was well away from the eshuast manifold,, go those newly wrapped wires into that clip, now, i dont seem to have the starter problem,,, it will sort of sag for a second on a engine start after car has been running, but it picked right up and starts... did the wrap help,, dont know,, i dont think it hurt,,, please note, i didnt figure this out by myself,, got lots of help from forum..