92 Chevy S-10 2.5L 4cyl?

i've been a master ASE technician for a few years now.... i've addressed this problem time and again. this totally sounds like the valve timing is off. first bring it up to top dead center on number one.if you aready done this bear with me... do it again. make sure the dot on the camshaft is top dead center and the crankshaft mark is at the o position. the distributor rotor should be pointing at the number one cylinder. check this before proceding... it is very important.