suzukis doesnt reverse why? on 2003 Suzuki Grand Vitara

it will reverse simi ok when it has been driven for a while during the day but when its been parked for more than a few hrs it refuses to back up. i push the gas peddel all the way down b4 it will move than it just bolts backwards.

Asked by for the 2003 Suzuki Grand Vitara
poss internal trans issue get a free diag at aamco and then shop price