I have a 02 ford escort with a 2.0 16 valve zetec bual over head cam motor.The serpentine belt had broke while driving. Tried driving it home and cut off and wouldn't start back up. The car was not over heated. Had it towed and put a new belt on still won't start. It backfired through the intake. I figured it jumped time. But I had it checked timing is not off. Used 1st cylinder and it's top and center. Valve cover has been taken off and everything is in time. I have replace the cam sensor and the crank shift sensor. Still won't start. It's getting fuel, and spark. Compression has been tested and it's good. All this has been done by a shop. They can't find the issue please help me.. We have exhausted all measures.. Please help.

 

If it is backfiring through the intake , has to be one of two reasons.
Either the valve timing is off or the ign timing is off or both.
The cam timing may have been set correctly, but the relation to the crankshaft could be off. This is one of those where the whole process has to be started from the very beginning and each step done correctly.