i have a 93 s10 blazer 4.3 vortec im pretty sure i have the timing right it gets good spark is getting gas but wont start it wont even backfire so if anyone can give me any help i would appreciate it

 

If the engine is turning over it needs 3 things to start and run :

air
fuel
spark

 

Check the fuel injectors, I had a Camaro doing the same thing found out that one of the injectors was bad and shorting out the others. It was getting spark had fuel pressure but would not fire. What I did 2 figure this out was had someone turn it overwhile Ipulled the harness off the injector itdidn't start, put the harness back on that one and moved 2 the next and so on, got to the last one pulled it off andit fired up, replaced that injector and haven't had a problem since.
Hope this helps

 

If you have that CPI fuel system, that system is noted for problems? Fuel pressure is critical. Any troublecodes?