Cranks but doesnt start

I am a self emplyed mechanic, if a motor cranks but does not start, that is not a starter, you need to see if you have gas or spark . is there a buzzing in the gas tank when you turn the key. if so then you have gas. now you needto see if you have spark. need 2 people to do this . pull a spark plug wire and stick a screw drive in the boot and crank the motor please stand back,and look for spark. if you have spark. then you need a crank position sensor thank you ted

REPLACING STARTER ON CAR THAT CRANKS BUT WONT START DOES NOTHING..CHECK FOR FUEL,BY SPRAYING STARTER FLUID IN T.BODY IF STARTS YOU KNOW YOU HAVE FUEL PUMP PROB,IF NOT CHECK FOR SPARK AT PLUGS

Check the Main Relay and fuse.
Hope this helps.