i have a 89 trooper 4x4 automatic transmission 4doors 4cyl, and it does not shift correctly because it shifts at 4500revs on normal drive (not full throtle), from 1st to 2nd runs like 30-35 mph. it shifts to 3rd, but for that i need to go hell fast!!! what could it be ??? does anyone has the same problem ????? i tried to adjust the throtle cable that goes into the trans but was useless.... a sensor maybe ?????? please help me!!