Governor Check
WARNING: This page does not describe the selected car, but rather 124 other vehicles, including the 1991 Chevrolet Pickup, 1991 Chevrolet Cab & Chassis, 1988 GMC Vandura Special, 1988 GMC Vandura, and 1988 GMC Value Van. However, it is still accessible from the selected car via links, so may be relevant.
- Raise vehicle on hoist (rear wheels off ground). Disconnect and plug vacuum line to modulator. Connect pressure gauge to transmission and tachometer to engine.
- Start engine, keep foot off brake pedal, move selector lever to Drive range, and check line pressure at 1000 RPM. Slowly increase engine speed to 3000 RPM and determine if line pressure drop of 10 psi (.7 kg/cm2 ) or more occurs.
- If no pressure drop occurs, inspect governor for stuck valve or weight, or restricted orifice in valve. Ensure governor valve entry and exhaust has .020" (.51 mm) minimum opening.
- Check governor feed system. Check control valve assembly or case screen. Check governor pipe for restrictions and proper fit in case holes. Control valve assembly should be disassembled, cleaned, and inspected if pressure drop of 10 psi (.7 kg/cm2 ) or more occurs (with transmission malfunction).