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

NO. 12 LACK/LOSS OF POWER-ACCELERATION/CRUISE REFERENCE CHART (MZI-3.7)

12	LACK/LOSS OF POWER-ACCELERATION/CRUISE
DESCRIPTION	Performance is poor under load (such as power down when climbing hills).
POSSIBLE CAUSE	Drive-by-wire control system operates with brake override system. Vacuum leakage Restriction in intake-air system Air leakage from intake-air system parts Poor fuel quality PCM DTC is stored Engine overheating Intake air temperature too hot Erratic signal to PCM APP sensor or related circuit malfunction MAF sensor or related circuit malfunction TP sensor or related circuit malfunction IAT sensor or related circuit malfunction CKP sensor or related circuit malfunction VSS or related circuit malfunction Erratic signal from CKP sensor Fuel leakage from fuel injector Fuel injector clogging Throttle body restriction or clogged Improper operation of drive-by-wire control system Restriction in exhaust system Inadequate fuel pressure Open or short in fuel pump related circuit Fuel pump mechanical malfunction Fuel line restriction or clogging Pressure regulator malfunction (built-in fuel pump unit) Improper A/C system operation Improper A/C cut-off operation PCV valve malfunction Purge control solenoid malfunction Erratic signal or no signal from CMP sensor Improper variable valve timing control operation Low engine compression Improper valve timing due to jumping out of timing chain ATX malfunction Brake dragging WARNING: The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before servicing the fuel system: 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 service information. (See BEFORE SERVICE PRECAUTION article.) (See AFTER SERVICE PRECAUTION article.) CAUTION: Disconnecting/connecting quick release connector without cleaning it may cause damage to fuel pipe and quick release connector. Always clean 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 (such as power down when climbing hills).

POSSIBLE CAUSE

Drive-by-wire control system operates with brake override system.
Vacuum leakage
Restriction in intake-air system
Air leakage from intake-air system parts
Poor fuel quality
PCM DTC is stored
Engine overheating
Intake air temperature too hot
Erratic signal to PCM
- APP sensor or related circuit malfunction
- MAF sensor or related circuit malfunction
- TP sensor or related circuit malfunction
- IAT sensor or related circuit malfunction
- CKP sensor or related circuit malfunction
- VSS or related circuit malfunction
Erratic signal from CKP sensor
Fuel leakage from fuel injector
Fuel injector clogging
Throttle body restriction or clogged
Improper operation of drive-by-wire control system
Restriction in exhaust system
Inadequate fuel pressure
- Open or short in fuel pump related circuit
- Fuel pump mechanical malfunction
- Fuel line restriction or clogging
- Pressure regulator malfunction (built-in fuel pump unit)
Improper A/C system operation
Improper A/C cut-off operation
PCV valve malfunction
Purge control solenoid malfunction
Erratic signal or no signal from CMP sensor
Improper variable valve timing control operation
Low engine compression
Improper valve timing due to jumping out of timing chain
ATX malfunction
Brake dragging
WARNING:
The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before servicing the fuel system:
- 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 service information.
  (See BEFORE SERVICE PRECAUTION article.)
  
  (See AFTER SERVICE PRECAUTION article.)
CAUTION:
- Disconnecting/connecting quick release connector without cleaning it may cause damage to fuel pipe and quick release connector. Always clean quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.