changed starter but still wont start!

I changed the starter on my friends sunfire gt the other day because it wasnt working. After replacing the starter the engine turns over but refuses to start. When you turn the key on you can hear the pump buzz like normal, but it just cranks and cranks without even firing. Anyone have any ideas...?:banghead:

What year and which engine?

Will it start if you spray carb cleaner into the intake while cranking?

If yes, then either no fuel pressure(need to test with a gage) or the injectors are not firing(Security problem?).....

If no, check for spark on all cylinders.....

also pull the vac line to the fuel pressure regulator and check for fuel in the line....

Any codes?

Before the no crank problem, the car started ok?

It's a 2000 gt. so I think it's 2.4..? I tried to spray carb cleaner and it didn't help. I'm gunna try checking spark thanks

Have you changed the Crank Shaft Position Sensor ? I have an 89 Cavalier that wouldnt start after changing the fuel pump and coils and stuff come to find out the the cps was bad.