I have a blazer that cranks but won't start. It has good spark, it is definitely getting fuel into the cylinders and the PSI at the schrader valve is right on 60 when the pump primes. Doesn't leak down very quickly either. I checked the ignition timing today, it was good. I brought cylinder #1 to tdc and the distributor rotor was just slightly past the arrow with the 6 molded into the side. Only a quarter inch, far less than one tooth difference on the distributor gear. I just put this engine in, the old engine ran but it knocked bad so I replaced it but now it won't start. I checked where the timing was on the old engine and it was actually a tooth behind where it should have been. (According to that arrow jutting in on the side and where the other engine was at) but because the other engine did run I set the timing back a tooth, turning counter clockwise. Still wouldn't start.

Can some one tell me what tells the PCM to fire the injectors when they do? If there is fuel , spark, and ignition timing maybe the injector timing is off? We did swap the crankshaft position sensor because the one on the donor engine was broken, and I swapped the sensor in the bottom of the distributor??? Camshaft sensor or spark pickup??

I swapped the coil, cap/rotor, wires , and plugs out of the old engine. I don't think it's a spark issue and when I pull the plugs out there coated in fuel. Any help would be appreciated!!