92 s10 blazer vortec w getting horrible mpg like 4 to 5 miles per hard starting poor performance when running. Recently bought this thing to fix it up but at loss now because I did a complete tune up as far as plugs wires cap and air filter and oil change. Replaced o2, air charge temperature, coolant temperature sensors did nothing. Cleaned egr did nothing any suggestions ?

Also changed the distributors rotar and reset the engine control computer

 

does it stall out? map sensor or spider injector?

 

92? thats TBI right? if it is, have you tried changing out the injectors? they could be either leaking, which you would noticed by the way that the motor would run, or they could be gummed up so its not getting enough fuel you are having to jump on it to get it to run the way you want.
just my .02

 

its a CPI (Vin W)
Do a fuel pressure test, search the forum and you will find all the info you need.

Pull your dipstick, and smell it, does it smell like gas?