I have started to have the same problem with my '82 with 174K+ miles- not related to heat or anything though- happens either stone cold or very hot. My workaround at present is to simply leave the key on, push it about 2-3 feet and pop the clutch in first gear- jumps/starts real easy. Then it starts with the key maybe another gazillion times before the inevitable... having read the horror stories about starter removal etc... (which I was quoted at only a 2.5 hour labor charge- Is this correct?) I'm going to wait awhile and se what happens...