No. 12 Lack/Loss Of Power-Acceleration/Cruise: Notes

POSSIBLE CAUSES DESCRIPTIONS

12	LACK/LOSS OF POWER - ACCELERATION/CRUISE
DESCRIPTION	Performance is poor under load (e.g., powers down when climbing hills).
POSSIBLE CAUSE	Improper A/C system operation Improper operation of A/C cut-off control Air leakage or restriction from intake-air system Loose turbocharger compressor-to-intake manifold duct connecting Turbocharger rotating assembly binding or dragging Wastegate valve malfunction (stuck open) Turbocharger malfunction Charge air cooler malfunction Variable swirl system malfunction Improper operation of electronic throttle control system Purge solenoid valve malfunction EGR system malfunction Brake dragging Low engine compression Poor fuel quality Vacuum leakage Incorrect signal to ignition coil Spark plug malfunction Engine overheating Throttle body malfunction Air cleaner restriction or dirty PCV valve malfunction Improper valve timing due to jumping out of timing chain Improper operation of variable valve timing control system Restriction in exhaust system or three-way catalytic converter (TWC) Leakage at exhaust manifold or turbocharger mounting flange Intermittent open or short fuel pump related circuit Inadequate fuel pressure (high-or low pressure side) Fuel pressure sensor or related circuit malfunction Suction control valve or related circuit malfunction (built-in high pressure fuel pump) Relief valve malfunction (built-in delivery pipe) High pressure fuel pump malfunction Improper fuel pump speed control operation Fuel pump mechanical malfunction Fuel line restriction or clogging Fuel injector malfunction Incorrect fuel injection timing Erratic signal from CKP sensor Erratic or no signal from CMP sensor ECT sensor or related circuit malfunction Manifold absolute pressure (MAP) sensor or related circuit malfunction Accelerator position sensor or related circuit malfunction MAF/IAT sensor or related circuit malfunction IAT sensor No.2 or related circuit malfunction Intermittent open or short circuit MAF sensor, accelerator position sensor, TP sensor and VSS Clutch slippage Injector driver module or related circuit 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 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. (See AFTER REPAIR PROCEDURE ). (See BEFORE REPAIR PROCEDURE ). CAUTION: Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to the fuel pipe and quick release connector. Always clean the quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.

LACK/LOSS OF POWER - ACCELERATION/CRUISE

DESCRIPTION

Performance is poor under load (e.g., powers down when climbing hills).

POSSIBLE CAUSE

Improper A/C system operation
Improper operation of A/C cut-off control
Air leakage or restriction from intake-air system
Loose turbocharger compressor-to-intake manifold duct connecting
Turbocharger rotating assembly binding or dragging
Wastegate valve malfunction (stuck open)
Turbocharger malfunction
Charge air cooler malfunction
Variable swirl system malfunction
Improper operation of electronic throttle control system
Purge solenoid valve malfunction
EGR system malfunction
Brake dragging
Low engine compression
Poor fuel quality
Vacuum leakage
Incorrect signal to ignition coil
Spark plug malfunction
Engine overheating
Throttle body malfunction
Air cleaner restriction or dirty
PCV valve malfunction
Improper valve timing due to jumping out of timing chain
Improper operation of variable valve timing control system
Restriction in exhaust system or three-way catalytic converter (TWC)
Leakage at exhaust manifold or turbocharger mounting flange
Intermittent open or short fuel pump related circuit
Inadequate fuel pressure (high-or low pressure side)
Fuel pressure sensor or related circuit malfunction
Suction control valve or related circuit malfunction (built-in high pressure fuel pump)
Relief valve malfunction (built-in delivery pipe)
High pressure fuel pump malfunction
Improper fuel pump speed control operation
Fuel pump mechanical malfunction
Fuel line restriction or clogging
Fuel injector malfunction
Incorrect fuel injection timing
Erratic signal from CKP sensor
Erratic or no signal from CMP sensor
ECT sensor or related circuit malfunction
Manifold absolute pressure (MAP) sensor or related circuit malfunction
Accelerator position sensor or related circuit malfunction
MAF/IAT sensor or related circuit malfunction
IAT sensor No.2 or related circuit malfunction
Intermittent open or short circuit MAF sensor, accelerator position sensor, TP sensor and VSS
Clutch slippage
Injector driver module or related circuit 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 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.
  (See AFTER REPAIR PROCEDURE ).
  
  (See BEFORE REPAIR PROCEDURE ).
CAUTION:
- Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to the fuel pipe and quick release connector. Always clean the quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.