See Figures 1 and 2
This system cuts off part of the fuel in the slow circuit of the carburetor to prevent overheating and afterburning of the exhaust system.
- Connect a tachometer to the engine.
- Start the engine and check that it runs normally.
- Pinch the vacuum hose to the vacuum switch.
- Gradually increase the engine speed to 3000 rpm. Check that the engine misfires slightly between 2400 and 3000 rpm.
Perform this procedure quickly to avoid overheating the catalytic converter.
- Release the hose and gradually increase the engine speed to 3000 rpm. Check that the engine operation is normal.
- With the engine at idle unplug the solenoid valve. Check that the engine misfires or stalls.
- If a problem is found check the switch and solenoid. If everything is normal connect the vacuum line and wiring.