I have a 1989 2.8 that i recently swapped the ecm from an exact car as mine same engine and same year beacuse it wasnt turning on the fuel pump. Before the car would change gears smoothly had more acceleration now the car struggles to accelerate and gets stuck around the second gear. The rpm goes up but it wont change. It is not displaying any truoble codes. What can be the problem? does the computer need to be reprogrammed or is it something like a speed or a tps sensor? PLs Help