94 Mazda MX6

PROBLEM: The car will not start.

The problem first occured when one day it took many cranks to start the car. Then while driving it one day, it just decided to turn off. Sounded like it ran out of gas even though it had half a tank. When I went to crank it, it wouldn't stay on. You could add a little gas for a bit to keep it cranked but once you let go of the gas it would turn off. Now it will turn over but not start. Long story short, we ended up replacing the fuel pump and fuel filter. That was not the problem. It is getting gas just fine. So we checked for spark from the spark plug wires. None of the wires are getting spark. I don't think all wires could be bad. So I replaced the distributor cap (no spark), the rotar button (no spark), the ignition coil (still no spark). Is there any way of checking the distributor? What else could it be? Could it be the ignition module? If so, where exactly is it, what does it look like, how can I check it, where can I purchase one? I prefer not to have to buy a whole distributor. Are there any other checks I can do before purchasing another part?