Rough Idle/Engine Stalls at Idle — Before Warm-up
F2-35flowchart9 ROUGH IDLE/ENGINE STALLS AT IDLE — BEFORE WARM-UP
Engine speed low or engine stalls or vibrates excessively at idle during warm-up.
NOTE
[TROUBLESHOOTING HINTS] (1) Low intake air amount: Volume air flow sensor stuck; Air cleaner element clogged; Air valve. (2) Low fuel injection control: Fuel injection control malfunction (Correction for coolant temperature). (3) Poor atomization.
Rough Idle/Engine Stalls at Idle — Before Warm-up
1
STEP 1: Is "00" displayed on SST with ignition switch ON? (Self-Diagnosis Checker, System Selector 49 B019 9A0, SELECT SW: A, 49 H018 9A1, Monitor Light) (page F2-73)
No
Diagnostic trouble code No. displayed: Check for cause (Refer to specified check sequence) (page F2-74)
Yes ("00" displayed): Go to next step
2
STEP 2: Is intake manifold vacuum correct at idle after warm-up? Vacuum: More than 450 mmHg {17.7 inHg}
No
Check for air leakage of intake-air system components
Yes: Go to next step
3
STEP 3: Is air cleaner element clean? (page F2-70)
No
Replace air cleaner housing element
Yes: Go to next step
4
STEP 4: Are ECM terminal voltages OK? 1C-Starter signal; 2E-Engine coolant temperature sensor; 3D-Sensor ground (page F2-141)
No
Check for cause (page F2-141)
Yes: Go to next step
5
STEP 5: Disconnect idle air control valve connector. Does engine speed increase after warm-up?
No
6
Replace IAC valve (page F2-95)