Chevrolet: Chevy Lumina wont start, chevy lumina, older cars

Question
My wife has a 1991 Chev. Lumina, 3.1 F1 Multi-Port.  One day she went to the store and car ran fine.  The next day, the car won't fire up.  There is plenty of battery/crank and it appears the engine is getting gas.  Can you help and please be specific, I'm a cracker-jack mechanic.
Someone suggested the coils.  Can you tell if only 1 is bad or do you have to replace all 3, if in fact that's what you may suggest.
Thanks again, you guys are usually right on the money.....Mike O.

Answer
hi
   the only thing that i can think of is the map sensor
as that is what it will do when it goes. or a computor should be pluged into it so it can tell you what it is that is wrong.or what is going on with it.I really do older cars but as far as i know when you have the trouble that you are having it is the sensor most of the time.and as far as the coils i think that  i would go for all 3 also.