TROUBLESHOOTING GUIDE — 8 ROUGH IDLE — ALWAYS
F-30spec table8 ROUGH IDLE — ALWAYS
DESCRIPTION: Engine vibrates excessively at idle in every condition.
NOTE
[TROUBLESHOOTING HINTS] (1) Air/Fuel mixture too lean: Air leakage; Fuel injection control malfunction; Low fuel line pressure. (2) One or more injectors not operating or clogged. (3) One or more spark plugs not sparking. (4) Injection timing misadjustment. (5) Low engine compression.
Troubleshooting steps 1-5
1
INSPECTIONCheck for correct intake manifold vacuum at idle; Vacuum: More than 450 mmHg (17.7 inHg)
RESULTYes
ACTIONGo to next step
1
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
2
INSPECTIONCheck if air cleaner element is clean — page F-75
RESULTYes
ACTIONGo to next step
2
INSPECTIONCheck if air cleaner element is clean — page F-75
RESULTNo
ACTIONReplace air cleaner element — page F-92
3
INSPECTIONCheck if '00' is displayed on Self-Diagnosis Checker with ignition switch ON — page F-78
RESULTYes
ACTIONGo to next step
3
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
4
INSPECTIONCheck switches for correct operation with Self-Diagnosis Checker Monitor Lamp and ignition switch ON — page F-89
RESULTYes
ACTIONGo to next step
4
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
5
INSPECTIONCheck if ECU terminal voltages are OK (2D, 2O and 2Q) — page F-129
RESULTYes
ACTIONGo to next step
5
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
See also
F-93INTAKE AIR SYSTEMF-75ENGINE TUNE-UPF-92INTAKE AIR SYSTEMF-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)