• Checks for leaky, sticky, or burnt valves, incorrect timing, accurate fuel pump vacuum and pressure and gas line leakage
• Gauge is calibrated from 0-30 Hg for Engine Vacuum readings and from 0-15 PSI (0.1 - 1.0kg/cm²) for Fuel Pump Pressure readings
• Includes rubber hose and tapered fitting

Testing Manifold Vacuum

1. The Engine should be warmed up to operating temperature and idling slightly higher than normal idling speed.
2. Connect the gauge to the intake manifold. Whenever possible, connect the gauge to the vacuum pipe on the inlet manifold in order to avoid any leaks that might exist in the windshield wiper or other connections.
3. With engine running at idle speed and choke valve fully open record vacuum reading.
4. Rapidly increase engine speed and record reading. (Open throttle).
5. Rapidly decrease engine speed and record reading. (Close throttle).
6. Add required correction factor to adjust readings to altitude where tests are performed.

Testing Fuel Pump Vacuum

1. Disconnect gas line from fuel pump inlet. Cap or plug line to prevent fuel leakage.
2. Connect tester to fuel pump and start engine while observing gauge. If fuel pump is in good condition, reading will gradually increase to approximately 10 inches (250mm) of vacuum.
3. Stop engine. Remove tester and reconnect the gas line.

Testing Fuel Pump Pressure

1. Disconnect fuel line at fuel pump outlet. (Between pump and carburetor).
2. Connect Tester to fuel pump and start engine. With engine running at idle speed. Observe reading on pressure half of dial face.
   1. Readings during idle should be from 1 ½ to 4 pounds (.10 to .30 kilograms) as specified by engine manufacturer. Higher then specified pressure can cause carburetor flooding, too rich a fuel mixture and poor gas mileage.
3. Stop engine and observe Tester reading for several minutes.
   1. Pressure reading should stay steady, then slowly decrease to zero. If pressure drops as soon as engine is stopped, check for worn fuel pump value or leaking pump housing or diagraph.
4. Remove Tester and reconnect gas line to fuel pump.