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.
1987 Mazda RX-7 Base, AutomaticFACTORY OEM SERVICE PROCEDURE
By-Pass Air Control Valve Check
- Warm up engine and run at idling speed. Using a tachometer, check that engine speed decreases when the By-pass Air Control (BAC) valve connector is disconnected. See Fig 1 .
- Remove BAC valve from vehicle if further testing is needed. Drain coolant, disconnect water and air relief solenoid valve tubes from BAC valve, remove attaching nuts and remove BAC valve. Disconnect BAC valve connector.
- Using an ohmmeter, check valve for resistance. Resistance should be 10.7-12.3 ohms. Apply battery voltage to terminals of BAC valve. Valve should make a clicking sound. If not, replace BAC valve.
Factory Service Tools
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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.
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