1996 tacoma 4wd 2.7 automatic crank but no start

my truck is a 1996 tacoma 4wd with the 2.7 and auto transmission. stopped one day and will not start. changed fuel pump,fuel filter,distributor,wires,plugs and wires and crankshaft position sensor. now it wont fire. mechanic said it was the ecm, so i ordered one online and now when u turn on the switch, the check engine light doesnt come on and it still wont fire. what else can it be. mechanic says the ecm i bought is defective cause check engine light wont come on. any ideals

 

What codes are recorded?

Was the check engine light on before the initial "stopped one day" event?

 

Have you verified it’s getting fuel and spark. It’s either air, fuel or spark.

 

Had the same thing happen.Sent the ECM off and had it repaired now everything works as it should.