'89 4.0 won't start

My Cherokee will crank merrily away, but won't start. The ignition module tested bad, so I replaced it and still have the same problem. Any suggestions? I do have a real mechanic to call on if it's something major, but I would prefer to keep my costs down by having an idea of what to tell him to check. Thanks.
Kate

If you're still getting no spark, it's probably the crank position sensor that's taken a permanent vacation. Ask your mechanic to check if the sensor's resistance is within spec.

I second Dr. Dyno.

Sometimes the CPS fails gradually and you'll notice rough running, hard starting, or skipping. The one on my '88 4.0L didn't do any of that. I ran flawlessly and reliably with no symptoms. Then one day it simply would NOT start.

Thanks guys. This gives me someplace to start. Computerized cars can be mind boggling, especially when one is somewhat feeble minded to begin with.

Kate