91 stock engine rebuild, new main harness, rebuilt stock turbos. All this bolted to the Automatic Transmission. The car shifts fine when cold or warm. Without O/D it runs 50MPH at 2500 RPMs. If I kick it down to passing gear, it shifts down and will not shift back into third. It will run 50MPH's at 4800 RPM's. Overdrive switch will not work once I kick it into passing gear. Letting the car cool down it works fine until passing gear is engaged. I have adjusted the TBS to 4.v volts. Did a transmission service and can not do an auto diagnostics due to the fact that It has no lights in the dash. So now I still looking for a Consult I. Thanks Al