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NO.11 ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES, BUCK/JERK, HESITATION/STUMBLE, SURGES [AJ] (VIN: JM0 LW10J300 301406-, JMZ LW69J7*# 307683-, JM8 LW28J**# 301514-, JM8 LW28A**# 301514- (Assumed))

BME010300000W08

11 | Engine stalls/quits-acceleration/cruise Engine runs rough-acceleration/cruise Misses-acceleration/cruise Buck/jerk-acceleration/cruise/deceleration Hesitation/stumble-acceleration

Surges-acceleration/cruise

DESCRIPTION | • Engine stops unexpectedly at beginning of acceleration or during acceleration. • Engine stops unexpectedly while cruising. • Engine speed fluctuates during acceleration or cruising. • Engine misses during acceleration or cruising. • Vehicle bucks/jerks during acceleration, cruising or deceleration.
• Momentary pause at beginning of acceleration or during acceleration
• Momentary minor irregularity in engine output
POSSIBLE CAUSE | • A/C system improper operation • Erratic signal or no signal from CMP sensor • Air leakage from intake-air system parts • Purge solenoid valve malfunction • IAC valve improper operation
• EGR valve malfunction
• Erratic signal from CKP sensor
• Low engine compression
• Vacuum leakage
• Poor fuel quality
• Erratic signal to ignition coil
• Air cleaner restriction
• PCV valve malfunction
• Improper valve timing due to jumping out of timing belt
• Restriction in exhaust system
• Intermittent open or short in fuel pump circuit
• Inadequate fuel pressure
• Fuel pump mechanical malfunction
• Fuel leakage from fuel injector
• Fuel injector clogging
• Intermittent open or short of MAF sensor, TP sensor and VSS
• ATX malfunction

  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 injuries 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.
  (See BEFORE SERVICE PRECAUTION [AJ].)
  (See AFTER SERVICE PRECAUTION [AJ].)

Diagnostic procedure

STEP | INSPECTION | ACTION
--- | --- | ---
1 | • Verify following:

  - Vacuum connection
  - Air cleaner element
  - No air leakage from intake-air system
  - No restriction of intake-air system
  - Proper sealing of intake manifold and components attached to intake manifold: EGR valve, IAC valve
  - Ignition wiring
  - Fuel quality: proper octane, contamination, winter/summer blend
  - Electrical connections
  - Smooth operation of throttle valve

• Are all items normal?
Yes
Go to next step.
No | Service as necessary. Repeat Step 1.
2 | • Connect WDS or equivalent DLC-2. • Turn ignition switch to ON (Engine OFF). • Retrieve any DTCs. • Is "PASSED" displayed? | Yes | No DTC is displayed: • Go to next step.
No | DTC is displayed: • Go to appropriate DTC test.
3 | • Is engine overheating? | Yes | Go to symptom troubleshooting "No.17 Cooling system concerns-Overheating".
No | Go to next step.
4 | • Connect WDS or equivalent to DLC-2. • Access RPM, MAF and TP PIDs. • Drive vehicle with monitoring PIDs. • Are PIDs within specification? (See PCM Inspection Using the SST (WDS or equivalent).) | Yes | Go to next step.
No | RPM PID: • Inspect CKP sensor and related harness for vibration and/or intermittent open/short circuit. MAF PID: • Inspect for open circuit of MAF sensor and related wire harness intermittently. TP PID: • Inspect if output signal from TP sensor changes smoothly. VSS PID:
• Inspect for open circuit of VSS and related wire harness intermittently.
5 | • Visually inspect CKP sensor and teeth of crankshaft pulley. • Are CKP sensor and teeth of crankshaft pulley normal? | Yes | Go to next step.
No | Replace malfunctioning part.
6 | • Inspect spark plug conditions. • Is spark plug wet, covered with carbon or grayish white? | Yes | Spark plug is wet or covered with carbon: • Inspect for fuel leakage from fuel injector. • Inspect ignition system for suspect cylinder. Spark plug is grayish white: • Inspect for clogged fuel injector.
No | Install spark plugs on original cylinders. Go to next step.
7 | • Remove and shake PCV valve. • Does PCV valve rattle? | Yes | Go to next step.
No | Replace PCV valve.
8 | • Inspect that throttle lever is resting on throttle valve stop screw and/or throttle valve orifice plug. • Is lever in correct position? | Yes | Go to next step.
No | Replace throttle valve body.
9 | • Inspect for restriction in the exhaust system. • Is there any restriction? | Yes | Inspect exhaust system.
No | Go to next step.
10 | • Install fuel pressure gauge between pulsation damper and fuel distributor. • Connect jumper wire between F/P terminal at DLC in engine compartment and GND. • Turn ignition switch to ON (Engine OFF). • Is fuel line pressure correct with ignition switch at ON?
(See FUEL LINE PRESSURE INSPECTION [AJ].)
Yes
Go to next step.
No | Zero or low: • Inspect fuel pump circuit. • Inspect for open fuel pump relief valve. • Inspect for fuel leakage inside pressure regulator. • Inspect for clogged main fuel line. High:
• Inspect pressure regulator for high pressure cause.
• Inspect for clogged fuel return line.
11 | • Visually inspect for fuel leakage at fuel injector O-ring and fuel line. • Service as necessary. • Does fuel line pressure hold after ignition switch is turned OFF? (See FUEL LINE PRESSURE INSPECTION [AJ].) | Yes | Go to next step.
No | Inspect pressure regulator diaphragm condition. • If condition is normal, inspect fuel injector. • If condition is not normal, replace pressure regulator.
12 |

  Note

  • Following test is for engine stall with A/C on. If other symptom exists, go to next step.

• Connect a pressure gauge to A/C low and high pressure side lines.
• Turn A/C on and measure low side and high side pressures.
• Are pressures within specifications?
Yes
Go to next step.
No | If A/C is always on, go to symptom troubleshooting "No.24 A/C always on/A/C compressor runs continuously". For other symptoms, inspect following: • Refrigerant charging amount • Condenser fan operation
13 |

  Note

  • Following test is performed for symptom with cruise control on. If other symptom exists, go to next step.

• Inspect cruise control system.
• Is cruise control system normal?
Yes
Go to next step.
No | Repair or replace malfunctioning part.
14 | • Disconnect vacuum hose between purge solenoid valve and intake manifold from purge solenoid valve side. • Plug opening end of vacuum hose. • Drive vehicle. • Does engine condition improve? | Yes | Inspect if purge solenoid valve is stuck open mechanically. Inspect EVAP control system.
No | Go to next step.
15 | • Visually inspect CMP sensor and projections of camshaft pulley. • Are CMP sensor and projections of camshaft pulley normal? | Yes | Go to next step.
No | Replace malfunctioning parts.
16 | • Inspect EGR system. • Is EGR system normal? | Yes | Go to next step.
No | Replace malfunctioning parts.
17 | • Is engine compression correct? | Yes | Inspect following: • Valve timing • Internal transaxle part
No | Inspect for cause.
18 | • Verify test results.

  - If normal, return to diagnostic index to service any additional symptoms.
  - If malfunction remains, inspect related Service Information and perform repair or diagnosis.

  • If vehicle is repaired, troubleshooting completed.
  • If vehicle is not repaired or additional diagnostic information is not available, replace or reprogram PCM.