[HO455]

Originally Posted by pjmoreland

I agree 45 mph would be a good cutoff. I am not sure if I'm going to be able to make the vacuum sensor work to my satisfaction. My impression is that you don't have to press the gas pedal down very far to make the vacuum level go almost completely away. I'd like to have the TCC stay locked maybe all the way to half throttle. Maybe a pedal-mounted switch from a 71-72 truck with a TH400 would be a better way to go. Another approach might be to tap into one of the pressure ports on the side of the 700R4 transmission to read the pressure associated with the TV cable position. I have thought it might work well to base the decision to lock or unlock the TCC on whether the gas pedal has been pressed down slowly vs. quickly.

On my 91 S-10 (700R4 behind a 4.3) the converter stays locked up when the throttle is pushed down slowly to maintain speed when going up a grade but unlocks immediately if I push down the throttle quickly. It seems that how guick the throttle moves is part of the equation.
Also the converter doesn't lock up below 45 mph on the S-10.

Thanks for the link to the sensor!