Air Valve
- To check air valve operation, allow engine to cool so coolant temperature is below 140°F (60°C). Start engine.
- Pinch hose going from air valve to air intake chamber. See Fig 1. When hose is pinched, engine speed should drop. After engine warm-up, engine speed should not drop more than 50 RPM when hose is pinched.
- If valve does not operate as specified, check for 12-volt power feed to air valve. If voltage is okay, ensure resistance across air valve terminals is 40-60 ohms at 176°F (80°C) with air valve closed. Replace air valve if defective.
NOTE:
Air valve is fed 12 volts by the circuit opening relay and is on the same circuit as fuel pump. At room temperature, gate valve should be slightly open when viewed through hose port on valve.