#
NO.10 ENGINE RUNS ROUGH/ROLLING IDLE [MZR-CD (RF Turbo)]

id0103f1820800

10 | ENGINE RUNS ROUGH/ROLLING IDLE
--- | ---
DESCRIPTION | • Engine the speed fluctuates between specified idle speed and a lower speed and the engine shakes excessively. • Idle speed is too slow and the engine shakes excessively.
POSSIBLE CAUSE | • Poor fuel quality • Air leakage from intake-air system • Intake-air system restriction • Incorrect idle speed • Engine overheating • Cooling fan system malfunction • A/C system improper operation • EGR system improper operation • EGR water cooler malfunction • Fuel leakage • Inadequate fuel pressure • Fuel pressure sensor or related circuit malfunction • Suction control valve malfunction (built-in supply pump) • Fuel pressure limiter malfunction (built-in common rail) • Fuel filter clogging • Fuel line restriction • Incorrect fuel injection timing • Erratic signal from CKP sensor • Erratic signal from CMP sensor • ECT sensor or related circuit malfunction • APP sensor or related circuit malfunction • MAF/IAT sensor malfunction • Neutral switch or related circuit malfunction • Supply pump malfunction • Fuel injector malfunction • Low engine compression • Improper valve timing • Engine compression excessive unbalance for each cylinder • Unbalanced fuel injection amount for each cylinder • Fuel injection learning improper Warning The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services: • Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel. • Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete "BEFORE REPAIR PROCEDURE" and "AFTER REPAIR PROCEDURE" described in this manual.

Diagnostic Procedure

STEP | INSPECTION | RESULTS | ACTION
--- | --- | --- | ---
1 | Inspect the following: • Fuel quality (e.g.: including water contamination, winter/summer blend) • Fuel line/fuel filter clogging • Loose bands on intake-air system • Cracks on intake-air system parts • Intake-air system restriction • Vacuum leakage • Cooling fan system operation Are all items normal? | Yes | Go to the next step.
No | Service if necessary Repeat Step 1.
2 | Is the engine overheating? | Yes | Go to symptom troubleshooting "NO.19 COOLING SYSTEM CONCERNS-OVERHEATING [MZR-CD (RF-Turbo)]."
No | Go to the next step.
3 | Connect the WDS or equivalent to the DLC-2. Turn the engine switch to the ON position. Retrieve any DTCs. Are any DTCs displayed? | Yes | DTC is displayed: Go to the appropriate DTC test. (See DTC TABLE [MZR-CD (RF Turbo)].) Communication error message is displayed: Inspect the following: • Open circuit between PCM control relay and PCM terminal 119 or 120 • Open circuit PCM control relay and PCM terminal 105 • PCM control relay stuck open • Open or poor ground circuit (PCM terminal 1, 2, 3, 114 or 117) • Poor connection to vehicle body ground
No | No DTC is displayed: Go to the next step.
4 | Note • The following test should be performed on vehicles with the A/C system. If the following test cannot be performed due to engine stalling, go to the next step. • Go to the next step for vehicles without an A/C system. Connect the pressure gauge to the A/C line. Turn the blower and the A/C switches on. Is the pressure within specifications? | Yes | Go to the next step.
No | A/C is always on: Go to the symptom troubleshooting "NO.26 A/C ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [MZR-CD (RF-Turbo)]". Other symptoms: Inspect the following: • Refrigerant charging amount • Cooling fan operation
5 | Depress the accelerator pedal slightly. Crank the engine. Does the engine start now? | Yes | Inspect the idle speed. (See ENGINE TUNE-UP [MZR-CD (RF Turbo)].)
No | Go to the next step.
6 | Inspect the APP sensor. (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [MZR-CD (RF Turbo)].) Is the APP sensor normal? | Yes | Go to the next step.
No | Replace the accelerator pedal component.
7 | Inspect for fuel leakage from the fuel pipe. Is any fuel leakage found on the fuel pipe? | Yes | Repair or replace if necessary.
No | Go to the next step.
8 | Start the engine and warm up to normal operation temperature. Verify the diesel particulate filter lamp condition. Does the diesel particulate filter lamp illuminate or flash? | Yes | Diesel particulate filter lamp illuminates: Perform manual diesel particulate filter regeneration procedure. (See DIESEL PARTICULATE FILTER REGENERATION [MZR-CD (RF Turbo)].) Diesel particulate filter lamp flashes: Perform the fuel injection learning, diesel particulate filter initialize, and clearing PCM memory then go to the next step. (See Injection amount correction.) (See DIESEL PARTICULATE FILTER RESET [MZR-CD (RF Turbo)].) (See DIESEL PARTICULATE FILTER DATA RESET [MZR-CD (RF Turbo)].)
No | Go to the next step.
9 | Visually inspect the CKP sensor and the teeth of the pulse wheel. Are the CKP sensor and the teeth of the pulse wheel normal? | Yes | Go to the next step.
No | Replace malfunctioning parts.
10 | Measure the gap between the CKP sensor and the teeth of the pulse wheel. Specification 1.5-2.5 mm {0.059-0.098 in} Is the gap within the specification? | Yes | Go to the next step.
No | Adjust the CKP sensor position.
11 | Visually inspect the CMP sensor and the teeth of the pulse wheel. Are the CMP sensor and the teeth of the pulse wheel normal? | Yes | Inspect the following PIDs: (See PCM INSPECTION [MZR-CD (RF Turbo)].) • ECT • IAT • MAF • RPM If the PID value is not as specified, repair or replace malfunctioning parts. If the PID value is normal, go to the next step.
No | Replace malfunctioning parts.
12 | Inspect the fuel pressure sensor. (See FUEL PRESSURE SENSOR INSPECTION [MZR-CD (RF Turbo)].) Is the fuel pressure normal? | Yes | Go to the next step.
No | Replace common rail.
13 | Inspect the suction control valve. (See SUCTION CONTROL VALVE INSPECTION [MZR-CD (RF Turbo)].) Is the suction control valve normal? | Yes | Go to the next step.
No | Replace the supply pump. (See SUPPLY PUMP REMOVAL/INSTALLATION [MZR-CD (RF Turbo)].)
14 | Is the engine compression correct? (See COMPRESSION INSPECTION [MZR-CD (RF Turbo)].) | Yes | Go to the next step.
No | Inspect the following: • Damaged valve seat • Worn valve stem and valve guide • Worn or stuck piston ring • Worn piston, piston ring or cylinder • Improper valve timing Service if necessary.
15 | Inspect the fuel injector. (See FUEL INJECTOR INSPECTION [MZR-CD (RF Turbo)].) Is the fuel injector normal? | Yes | Go to the next step.
No | Repair or replace if necessary. (See FUEL INJECTOR REMOVAL/INSTALLATION [MZR-CD (RF Turbo)])
16 | Inspect the EGR system operation. Is the EGR system operation normal? | Yes | Go to the next step.
No | Repair or replace the malfunctioning part according to EGR system operation results.
17 | Inspect the EGR water cooler for the following: • Coolant passage clogging/restriction • Exhaust gas clogging/restriction Is EGR water cooler normal? | Yes | Remove and inspect the supply pump and common rail.
No | Service if necessary.
18 | Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR-CD (RF Turbo)].) • If the malfunction remains, inspect the related Service Information and perform repair or diagnosis. - If the vehicle is repaired, troubleshooting completed. - If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if later calibration is available. Retest.