Rough Or Unstable Idle
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2002 Mazda Tribute, 2002 Mazda Protege5, 2002 Mazda Protege, 2002 Mazda Millenia, and 2002 Mazda MX-5 Miata. However, it is still accessible from the selected car via links, so may be relevant.
- Check for A/C compressor continuous operation (always on).
- Check for A/C condenser fan circuit malfunction.
- Check for A/C relay circuit malfunction.
- Check for air charging pressure control system malfunction (Millenia 2.3L).
- Check for Camshaft Position (CMP) sensor malfunction.
- Check for Crankshaft Position (CKP) sensor malfunction.
- Check for damaged sensor ring on crankshaft pulley.
- Check for damaged sensor wheel on camshaft.
- Check for EGR system malfunction.
- Check for fuel injector malfunction.
- Check for Pressure Regulator Control (PRC) system malfunction.
- Check for fuel pressure regulator malfunction.
- Check for fuel pulsation damper malfunction.
- Check for fuel pump malfunction.
- Check for Idle Air Control (IAC) valve malfunction.
- Check for incorrect A/C refrigerant charge.
- Check for intake air system leak.
- Check for incorrect gap between CKP sensor and crankshaft pulley.
- Check for incorrect ignition timing due to Crankshaft Position (CKP) sensor malfunction or damaged crankshaft pulley.
- Check for incorrect valve timing.
- Check for low engine compression.
- Check for overheating engine.
- Check for PCV valve malfunction.
- Check for poor fuel quality.
- Check for Power Steering Pressure (PSP) switch circuit malfunction.
- Check for purge solenoid valve malfunction.
- Check for restricted exhaust system.
- Check for restricted fuel filter or fuel inlet sock.
- Check for restricted or plugged fuel lines.
- Check for spark plug malfunction.
- Check for spark plug wire malfunction.
- Check for Variable Valve Timing (VVT) system malfunction.