I recently rebuilt my transmission and now when it is cold it will not go into gear. Hooked up to main pressure and intermittently main pressure goes to 0. Replaced valve body with another valve body same thing. I have built a few turbo 350's and never had a problem. New torque convertor, transgo shift kit, modulator valve. Went out yesterday when it was 70 degrees out and it worked just fine. Went out this morning when it was cool and it acted up for just a second. I just don't know what I could have missed. :spank:
