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.
1990 Mazda RX-7 GTU, AutomaticFACTORY OEM SERVICE PROCEDURE
By-Pass Air Control (BAC) Check
- Warm engine and allow to idle. Connect a jumper wire to ground at single-pin Green connector near battery. Install tachometer to engine. Note engine RPM.
- Disconnect BAC solenoid valve connector. See Fig 1 . Note engine RPM. Engine speed should decrease with connector removed. Reinstall solenoid valve connector.
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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