Idrove my sunfire yesterday now today it cranks but won,t start.recently had new fuel pump installed,new battery, new plugs@wires?? it,s a 2002pontiac sunfire 4 door 2.2lter

check your timing chain or timing belt.

Won't crank or will crank but won't start? Two completely different issues. Check any wiring anywhere even close to where you were working. Chances are there is either a loose connection at the starter or a disconnected/loose plug-in connection somewhere close to the area of recent work. If it won't crank at all then start at the battery and check the major connections for tightness and cleanliness. If the car worked properly yesterday and not today after the work then you should not have to look too far to find the bad connection.

You can't tell weak too well just looking

Check for injector pulse while cranking
like you did for spark

Check fuel pressure KO/EO

Won't turn over or won't start?

Has to turn over fairly fast

Check for fuel pressure & either spark or
injector pulse while cranking

BAD COIL OR IGNITION MODULE INSIDE DISTRIBUTOR RUN OHM TESTS TO VERIFY

Definitley NOT an O2 sensor(they don't even do anything for the startup).What happens if you shoot some starting fluid in it?

scanned wont pick up failed fuel pump--or clogged fuel filter check and test wiring --relays--connections and fuses

You could have a bad pump motor in your fuel pump. You will hear the "hum" of the pump motor but it won't continuously feed enough pressue to the system.
When you prime it the engine will draw enough to run for a bit then quit. They usually dry out if not kept full and sunfire fuel pumps are noted for this type of failure.
Try a used one for about 75 bucks. My kids Sunfire did exactly the same thing.

This is Caused by the Fuel Pump. If you remove the Fuel Pump relay and it will try to Crank, You have a Bad Fuel Pump. I do Believe that the Fuel Pump is located inside the Fuel Tank on the Sunfire. Not an easy Repair But, Necessary

Needs Crank sensor. Good luck