About a year after having the trans overhauled on my '94 4.0 with ZF trans, it wouldn't shift out of first until about 3000RPM and then usually went into Limp Home. Mechanic who overhauled it decided it was a solenoid, which was replaced. Shifts became even more erratic, but when I had to put about 20 road miles on car and got it good and warm, it shifted perfectly for the rest of that trip - so smooth you could barely feel. Next morning, one rough shift out of first, then Limp Home. Lately just starts in Limp Home. Replaced ECM & no difference. Are we down to trying to find an intermittent short, or is there something we're missing?