for what it's worth...here's my 2 cents....my 1990 300TE was idling extremely poorly and the transmission was acting like a dick...not shifting out of 1st until around 3000 and then just jumping through 2nd into 3rd like an idiot. Extremely frustrating....replaced the coolant temp sensor and changed the plugs and the engine straightened up...then reset the tranny shift points back to factory specs and all is well....good luck