I have a '97 Mercury Mountaineer 2WD. It runs great esp. when cool or cold. However, when it warms up I have to get the RPMs up to 2500 and let off on the throttle before it will shift into all gears. There is intermittent times when it will shift fine when warm but I can't figure it out. It did get progressively worse about it running fine before warm up...that is it took less time before malfunction over time. I've checked TPS, fluid/filter, VSS and the voltages required for them. It doesn't slip, it just doesn't shift unless I throttle back. Does anyone know why. Damn online mechanics don't know diddly squat. I've told them same info. I even tried CARTALK but they don't answer. Probably because they don't know either.