after sitting a few years,and a water pump pulley change ,i cant get itto start it cranks i tried starter fluid the back fire blew apart air filter box.that was the only thing that i got out of it.i checked fuel and spark.any suggestions?

If you messed with the timing belt, sounds like you installed it wrong. A common mistake. Also, go easy on the starter fluid. Too much and you will crack a piston. 

Edited March 23, 201511 yr by john in KY

Cam timing sounds off.