I ended up not changing the solenoids first. I bought a 5k potentiometer to chase after my hunch with the overheating making it shift right. I measured the resistance of the engine coolant temperature (ECT) sensor to be 260 Ohms at operating temperature. I took the connector that attached to the ECT and attached my potentiometer and made the resistance 150 Ohms. The car shifted wonderfully through all gears and went into overdrive also. I went and purchased a new ECT and replaced the old one. The car continued to flare from 2nd to 3rd and the resistance at operating temperature was 270 Ohms on the new ECT. I'm not sure why a lower resistance alows the car to shift right, but I also considered the thermastat being bad and not letting the car warm up enough, but I just recently replaced that with the head gasket.
Saturday, November 5th, 2011 AT 6:41 PM