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NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE [AJ] (VIN: JMZ LW19J7*# 300001-, JM0 LW10J300 300001-301405, JM6 LW10J300 300001-, JM8 LW28J**# 300001-301513)

BME010300103217

12 | Lack/loss of power-acceleration/cruise
DESCRIPTION | • Performance is poor under load (e.g. power down when climbing hills).
POSSIBLE CAUSE | • Improper A/C system operation • Erratic signal or no signal from CMP sensor • Air leakage from intake-air system parts • IMCC malfunction • Purge control solenoid malfunction
• EGR valve malfunction
• Brake dragging
• Erratic signal from CKP sensor
• Low engine compression
• Vacuum leakage
• Poor fuel quality
• Spark leakage from ignition coils
• 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 SERVICE PRECAUTION" and "AFTER SERVICE PRECAUTION" described in this manual.
  (See BEFORE SERVICE PRECAUTION [AJ].)
  (See AFTER SERVICE PRECAUTION [AJ].)

Diagnostic procedure

STEP | INSPECTION | ACTION
--- | --- | ---
1 | • Verify the 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
  - Fuel quality: proper octane, contamination, winter/summer blend

• Are all items normal?
Yes
Go to the next step.
No | Service if necessary. Repeat Step 1.
2 | • Connect the WDS or equivalent to the DLC-2. • Turn the ignition switch to the ON position (Engine off). • Retrieve any DTCs. • Is "PASSED" displayed? | Yes | No DTC is displayed: • Go to the next step.
No | DTC is displayed: • Go to the applicable DTC inspection. (See DTC TABLE [AJ] (VIN: JMZ LW19J7*# 300001-, JM0 LW10J300 300001-301405, JM6 LW10J300 300001-, JM8 LW28J**# 300001-301513).)
3 | Is the engine overheating? | Yes | Go to symptom troubleshooting "No.17 Cooling system concerns-Overheating". (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [AJ] (VIN: JMZ LW19J7*# 300001-, JM0 LW10J300 300001-301405, JM6 LW10J300 300001-, JM8 LW28J**# 300001-301513).)
No | Go to the next step.
4 | • Connect the WDS or equivalent to the DLC-2. • Access RPM, MAF, TP and VSS PIDs. • Drive the vehicle with monitoring PIDs. • Are PIDs within the specification? (See PCM Inspection Using the WDS or Equivalent.) | Yes | Go to the next step.
No | RPM PID: • Inspect the CKP sensor and the related wiring harness for vibration and/or intermittent open/short circuit. MAF PID: • Inspect for intermittent open circuit of the MAF sensor and the related wiring harness. TP PID: • Inspect if the TP sensor output increases smoothly. VSS PID:
• Inspect for intermittent open circuit of the VSS and the related wiring harness.
5 | • Visually inspect the CKP sensor and teeth of the crankshaft pulley. • Are the CKP sensor and teeth of the crankshaft pulley normal? | Yes | Go to the next step.
No | Replace the malfunctioning part.
6 | • Inspect the spark plug conditions. • Is the spark plug wet, covered with carbon or grayish white? | Yes | Spark plug is wet or covered with carbon: • Inspect for fuel leakage from the fuel injector. Spark plug is grayish white: • Inspect for the clogged fuel injector.
No | Install the spark plugs on original cylinders. Go to the next step.
7 | • Remove and shake the PCV valve. • Does the PCV valve rattle? | Yes | Go to the next step.
No | Replace the PCV valve.
8 | • Inspect for restriction in the exhaust system. • Is there any restriction? | Yes | Inspect the exhaust system.
No | Go to the next step.
9 | • Install a fuel pressure gauge between the pulsation damper and the fuel distributor. • Connect a jumper wire between F/P terminal at DLC in the engine compartment and GND. • Turn the ignition switch to the ON position (Engine off). • Is fuel line pressure correct with the ignition switch at the ON position?
(See FUEL LINE PRESSURE INSPECTION [AJ].)
Yes
Go to the next step.
No | Zero or low: • Inspect the fuel pump circuit. • Inspect for open fuel pump relief valve. • Inspect for fuel leakage inside the pressure regulator. • Inspect for clogged main fuel line. High:
• Inspect the pressure regulator for high pressure cause.
• Inspect for clogged fuel return line.
10 | • Inspect the IMCC operation. • Does the IMCC work properly? | Yes | Go to the next step.
No | Repair or replace the malfunctioning part.
11 |

  Note

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

• Connect a pressure gauge to the A/C low and high side pressure lines.
• Turn the A/C on and measure low side and high side pressures.
• Are pressure within the specifications?
Yes
Go to the next step.
No | If the A/C is always on, go to symptom troubleshooting "No.24 A/C always on/A/C compressor runs continuously". (See NO.24 A/C ALWAYS ON/A/C COMPRESSOR RUNS CONTINUOUSLY [AJ] (VIN: JMZ LW19J7*# 300001-, JM0 LW10J300 300001-301405, JM6 LW10J300 300001-, JM8 LW28J**# 300001-301513).)
For other symptoms, inspect the following:
• Refrigerant charging amount
• Condenser fan operation
12 | • Inspect the A/C cut-off operation. • Does the A/C cut-off work properly? | Yes | Go to the next step.
No | Inspect the A/C cut-off system components.
13 | • Disconnect vacuum hose between the purge solenoid valve and the intake manifold from the purge solenoid valve side. • Plug opening end of vacuum hose. • Drive the vehicle. • Does the engine condition improve? | Yes | Inspect if the purge solenoid valve is stuck open mechanically. Inspect the EVAP control system.
No | Go to the next step.
14 | • Visually inspect the CMP sensor and projections of the camshaft pulley. • Are the CMP sensor and projections of the camshaft pulley normal? | Yes | Go to the next step.
No | Replace the malfunctioning part.
15 | • Inspect the EGR system. • Is the EGR system normal? | Yes | Go to the next step.
No | Replace the malfunctioning part.
16 | • Is the engine compression correct? | Yes | Inspect the following: • Valve timing • Internal transaxle components • Brake system for dragging
No | Inspect for cause.
17 | • 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 the PCM.