I have a 1991 Olds Cutlass Supreme that won't start how can I rule out the timing chain, car turns over well dose not fire at all??

You may be able to inspect by removing the oil filler cap while cranking and watch for rocker arm movement. Otherwise, a compression test should be revealing.

It could be something as simple as replacing the ignition control module.

You could always remove the front valve cover and observe if the valves are moving. Also remove one plug and feel for TDC and test valve lash #1 cyl. for slipped timing chain.