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.
Description & Operation
All Honda engines have ignition control systems to lower emission levels, maximize fuel economy and improve engine performance. The system is designed to advance and retard ignition timing as necessary.
Vehicles use a vacuum solenoid valve which is operated by the control unit. Control unit receives signals from intake air temperature sensor and thermosensor. Models with auto. trans. also receive signals from ignition coil, vacuum switch C and speed sensor. When the vacuum control solenoid is open, intake manifold vacuum is allowed to enter the distributor vacuum advance unit.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.