98 plymouth breeze engine turns over will not start

Check fuel pressure and injector pulses

Fuel pressure is 50 psi as it should be. checked crank and cam sensors checked good with in spec's, checked both fuel pump and ASD relays they checked good,here's what has me puzzled now when crank and cam semsors are connected I get fuel preesure but no fire now with cam sensor disconnected I get both fuel and fire but no engine start up i hear popping going on in the cylinders and after several attempts it will blow back through the trottle body but only unbrunt fuel??

Check the crankshaft positon sensor again