Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Duty Solenoids
The duty solenoid(s) are solenoid valves that are operated by the control unit. The solenoid(s) open and close at a constant rate of about 40 cycles per second, though the "ON" time can vary. When the engine is being monitored by the oxygen sensor and control unit (closed loop), the average "ON" time is 30-40%. This time determines the air/fuel ratio and can be measured using a dwell meter.
The duty solenoids for the 2-bbl. carburetor are located on the intake manifold and are connected to the carburetor by air hoses. A small air cleaner is provided to filter the air which enters the carburetor through the duty solenoids. The duty solenoid for the 1-bbl. carburetor is mounted on the air horn of the carburetor.
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.