How can I tell if my torque converter is locking up in my 700r. I have an 85 Berlinetta (LG4). On the highway, the car goes into O/D and I lift off of the accelerator. If I get back on the gas a little, the car seems lag or slip then downshift into 3rd. It seems like it is not sure what gear it wants. I could continue doing this by lifting for O/D shift then touching the gas.

Does this sound like a TV cable problem, converter problem or something else?