Had a fire due to o ring where gas lines going into spider. Pulled motor and trans. All new gasket and timing chain on motor. Pulled wiring harnes and checked continuity in EVERY wire going to every sensor ect. New parts include distributor, wires, plugs, crankshaft sensor, ecm, coil, module,knocksensor, spider injector,neutral safety switch, oil pressure switch.
I have no spark. It's got me second guessing the alignment of the timing chain and gears. Will that cause absolutely no spark?

 

That will not. Do you have power to the coil?

 

no I traced it to the crankshaft sensor. Had voltage but when I turned the crank by hand and no switching voltage. Come to find out it wasn't seated flush so it wasn't picking relaying signal to ecm. By then it was to late to try and start truck.
When I put different ecm in blazer do I have to do passlock again. The reason I say again is I got stranded with key stuck in ignition. Long story short I put in switched push start and did passlock. Directions with new ecm said to do passlock but when I tried the security light never goes out. Solid not flashing.