2000 ES replaced water pump- won't start

The car was overheating.We figured that it was the water pump. We drove it into our barn- when we started this process- so it was running. Replaced the water pump with all the right tools- made sure the timing didn't get off track. Now it won't start. We tested the fuel pump, spark plugs, checked the sensors and such to make sure nothing was missed. It will turn but won't crank on up.

Any suggestions?