Hi All, when I engage my transmission in drive or reverse it just wants to tear everything, example when on a stone driveway when putting in drive or reverse as soon as i release the brake pedal it spins the wheel like crazy without touching the gas , any idea what causes that? thanks,
Other than high idle, Vacuum Modulator or 'throttle valve' controls the C4 trannys' internal hydraulic control pressure. Vacuum line to engine intake is often disconnected or modulator is defective and results in slamming shifts and jerky starts. https://www.motortrend.com/how-to/mump-1203-understanding-automatic-transmissions/ '76 Comet GT - 200cid with C4 - modulator is at lower right side of tranny . (bottom left in picture): have fun
