buick century shuts off after 15-20 minutes

1992 3.3 v6 buick century shuts off after 15-20 minutes. I check for spark on spark wire cable - none. Replaced ignition module - the problem did not go away. Can the problem be the crankshaft position sensor ?

That is what I would change next. The CPS will cause just exactly the problem you are indicating.

I will try it and let you know...Thank You....ED