Cadillac Repair: Stalls after runs for about 20-30 min, spark plugs, spark plug

Question
My 89 seville stalls after it runs for 20-30 min.  I changed the filter and pump w/ no avail.  The inside of the tank looks clean (no debris floating).  it starts with loss of power and then eventually stalls.  If I let it sit for about 15-30 min it usually starts back up and I can make it home before it stalls again.  Only thing I can think is Ignition control module is going south, any Ideas?

Answer
FIRST you need to determine if your losing fuel to the engine or spark to the spark plugs when this fault occurs.

See if you have any spark to a spark plug when this fault occurs.

IS or HAS the CHECK ENGINE light ever illuminated while driving the vehicle and if it HAS, What code or codes are you getting from the computers ?.