TROUBLESHOOTING GUIDE — 9 LOW IDLE SPEED/ROUGH IDLE — BEFORE WARM-UP
F-32spec table9 LOW IDLE SPEED/ROUGH IDLE — BEFORE WARM-UP
DESCRIPTION: Engine speed low or engine vibrates excessively at idle during warm-up.
NOTE
[TROUBLESHOOTING HINTS] (1) Low intake air amount: Airflow meter stuck; Air cleaner element clogged; Idle speed control [Air valve, Correction for coolant temperature]. (2) Low fuel injection amount: Fuel injection control malfunction (Correction for coolant temperature). (3) Poor atomization of fuel: Low RVP (summer) fuel used in cold weather.
Troubleshooting steps 1-5
1
INSPECTIONCheck if '00' is displayed on Self-Diagnosis Checker with ignition switch ON — page F-78
RESULTYes
ACTIONGo to next step
1
INSPECTIONCheck if '00' is displayed on Self-Diagnosis Checker with ignition switch ON — page F-78
RESULTNo
ACTIONMalfunction Code No. displayed: Check for cause (Refer to specified check sequence) — page F-80. "88" flashes: Check ECU terminal 1F voltage — page F-128; Voltage: Approx. 12V (Ignition switch ON); If OK, replace ECU — page F-127; If not OK, check wiring between ECU and Self-Diagnosis Checker — page F-7
2
INSPECTIONCheck switches for correct operation with Self-Diagnosis Checker Monitor Lamp and ignition switch ON — page F-89
RESULTYes
ACTIONGo to next step
2
INSPECTIONCheck switches for correct operation with Self-Diagnosis Checker Monitor Lamp and ignition switch ON — page F-89
RESULTNo
ACTIONLamp not ON/OFF with specified switch: Check for cause (Refer to specified check sequence) — page F-90. Lamp always ON: Check wiring between ECU terminal 1D and Self-Diagnosis Checker — page F-7
3
INSPECTIONCheck if ECU terminal voltages are OK (2D, 2O and 2Q) — page F-129
RESULTYes
ACTIONGo to next step
3
INSPECTIONCheck if ECU terminal voltages are OK (2D, 2O and 2Q) — page F-129
RESULTNo
ACTIONCheck for cause (Refer to "Check Point for Each Terminal") — page F-132
4
INSPECTIONCheck for correct intake manifold vacuum at idle; Vacuum: More than 450 mmHg (17.7 inHg)
RESULTYes
ACTIONGo to next step
4
INSPECTIONCheck for correct intake manifold vacuum at idle; Vacuum: More than 450 mmHg (17.7 inHg)
RESULTNo
ACTIONCheck for air leakage of intake air system components — page F-93
5
INSPECTIONCheck if air cleaner element is clean — page F-75
RESULTYes
ACTIONGo next step
5
INSPECTIONCheck if air cleaner element is clean — page F-75
RESULTNo
ACTIONReplace air cleaner element — page F-92
See also
F-78SELF-DIAGNOSIS FUNCTIONF-80SELF-DIAGNOSIS FUNCTIONF-128CONTROL SYSTEM - Engine Control Unit Terminal Voltage TableF-127CONTROL SYSTEM - Engine Control Unit InspectionF-7OUTLINE - WIRING DIAGRAMF-89SELF-DIAGNOSIS FUNCTIONF-90SELF-DIAGNOSIS FUNCTIONF-129CONTROL SYSTEM - Engine Control Unit Terminal Voltage Table (continued)F-132CONTROL SYSTEM - Check Point for Each Terminal (continued)F-93INTAKE AIR SYSTEMF-75ENGINE TUNE-UPF-92INTAKE AIR SYSTEM