1992 Chevy Camaro starting problems

I have a 92 Chevy Camaro z28 with 40,000 miles. It has developed a starting problem. Sometimes it will start fine and when turn off the engine it will not start the engine turns over. Let it set for a few days then it will start but during that time I will have replaced the coil. The speedo will stop work from time to time but will start working again. It start just before the starting problems.