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.
1989 Mazda B2600i BaseFACTORY OEM SERVICE PROCEDURE
Signal Inspection
- Warm engine to operating temperature and allow to idle. Connect dwell meter to White check connector pin No. 1. Disconnect vacuum hose from vacuum sensor and plug hose.
- Connect vacuum pump to vacuum sensor. See Fig 1 . Apply 19.7 in. Hg. Verify dwell meter registers in the 20-70 degree range. Release vacuum. Verify dwell meter indicates a fixed zero degrees. If not, check vacuum sensor and "1E" terminal voltage of ECU. See PIN VOLTAGE CHARTS article.
- Remove vacuum pump and reconnect vacuum hose. Increase engine speed to 4500 RPM. Verify dwell meter indicates a fixed zero degrees. If reading is 72 degrees, check idle and neutral switches. If reading is other than zero or 72 degrees and other devices test within specification, replace ECU.
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.