So my 96 (97 or 98 engine) blazer is annoying me at the moment. Runs fine and makes plenty of power when cold and runs fine (no sputtering or dieing) when warm but it just seems to lack horribly in the bottom end when it is warm. Only thing i know of with it is the battery is bad and needs replaced and its pretty dang loud (kind of like a airplane) on when accelerating. Any ideas? Engine is only at 70k from a 97 or 98 s10 not sure on the trans if its original its 155k. Was thinking timing or maybe the trans needs serviced fluid looks clean on the dipstick though and it will cruise at 80 mph just fine all my dash lights work also but the it doesn't have the check engine light on or anything and doesn't have any codes.

I am comparing this to my v8 truck and our 3.0l ish v6 oldsmobile intrigue both are pretty snappy

 

Have you cleaned the MAF sensor? When was the last time a tune up was performed (plugs, wires, cap & rotor - remember, these trucks prefer AC Delco caps & rotors)?