would like to know why after installing rebuilt transmission for the 2nd time that there is no acceleration above 1000 rpm

have a 2002 s10 pickup, 4.3 ltr vortec, vin. code w,SB,SC,automatic
transmission.
tranny went bad had it rebuilt,reinstalled transmission the 1st time, started
engine,motor would rev up when pedal was push,and return to idle upon
pedal release,problem was transmission pump gears were misaligned and
transmission failed to work,removed transmission again and
repaired,reinstalled tranny, it worked fine,backed out of shop attempted to
drive down the street would only accelerate to 1000 rpm,ran diagnostic scan
code came back as a bad mass airflow sensor,installed new sensor,still
same problem, upon raising the hood with the engine running at idle and
truck in park, i reached up and pushed throttle linkage to rev engine up and
noticed that as engine revved the 3" air intake would suck itself flat, removed
air intake hose from throttle body and engine would still only rev to between
3k-3.5k.and the check engine light is not on.
would anybody have an idea on why this problem would occur after a
transmission install?