No.10 Low Idle/Stalls During Deceleration: Notes

WARNING: This page is about a different car, the 2005 Mazda RX-8. However, it is still accessible from the selected car via links, so may be relevant.

NO.10 DESCRIPTION AND POSSIBLE CAUSE

10	LOW IDLE/STALLS DURING DECELERATION
DESCRIPTION	The engine stops unexpectedly at the beginning of deceleration or recovery from deceleration.
POSSIBLE CAUSE	Vacuum leakage Air leakage from intake-air system Air suction at intake-air system (between MAF sensor and intake part) Improper operation of drive-by-wire control system (abnormal accelerator position and TP signals to PCM) Drive-by-wire control system operates in fail-safe mode (abnormal accelerator position and TP signal to PCM) Throttle body malfunction (restriction, stuck closed) Evaporative emission control system malfunction Improper operation of fuel cut control Fuel injector improper operation Fuel injector malfunction (leakage, clogging, improper injection amount) Inadequate fuel pressure Pressure regulator (integrated in fuel pump unit) Fuel pump mechanical malfunction Fuel line restriction or clogging MAF sensor improper installation MAF sensor or related circuit malfunction (abnormal signal to PCM) Brake switch or related circuit malfunction (abnormal signal to PCM) Neutral/CPP switch or related circuit malfunction (abnormal signal to PCM) TR switch or related circuit malfunction (abnormal signal to PCM) Low engine compression Engine internal malfunction Abnormal engine oil condition (viscosity, deterioration) Low oil pressure Excessive fuel pressure Air mixed in oil line Metering oil pump malfunction Leakage or clogging in oil pipe Leakage or clogging in oil nozzle Improper A/C magnetic clutch malfunction Misfire Improper operation of torque converter clutch control (AT) Loose installation of engine mounts WARNING: The following troubleshooting flow chart contains 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 REPAIR PROCEDURE" and "AFTER REPAIR PROCEDURE" described in this article. (See BEFORE REPAIR PROCEDURE .) (See AFTER REPAIR PROCEDURE .) CAUTION: Disconnecting/connecting quick release connector without cleaning it may possibly 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.

LOW IDLE/STALLS DURING DECELERATION

DESCRIPTION

The engine stops unexpectedly at the beginning of deceleration or recovery from deceleration.

POSSIBLE CAUSE

Vacuum leakage
Air leakage from intake-air system
Air suction at intake-air system (between MAF sensor and intake part)
Improper operation of drive-by-wire control system (abnormal accelerator position and TP signals to PCM)
Drive-by-wire control system operates in fail-safe mode (abnormal accelerator position and TP signal to PCM)
Throttle body malfunction (restriction, stuck closed)
Evaporative emission control system malfunction
Improper operation of fuel cut control
Fuel injector improper operation
Fuel injector malfunction (leakage, clogging, improper injection amount)
Inadequate fuel pressure
Pressure regulator (integrated in fuel pump unit)
Fuel pump mechanical malfunction
Fuel line restriction or clogging
MAF sensor improper installation
MAF sensor or related circuit malfunction (abnormal signal to PCM)
Brake switch or related circuit malfunction (abnormal signal to PCM)
Neutral/CPP switch or related circuit malfunction (abnormal signal to PCM)
TR switch or related circuit malfunction (abnormal signal to PCM)
Low engine compression
- Engine internal malfunction
- Abnormal engine oil condition (viscosity, deterioration)
- Low oil pressure
- Excessive fuel pressure
- Air mixed in oil line
- Metering oil pump malfunction
  - Leakage or clogging in oil pipe
  - Leakage or clogging in oil nozzle
Improper A/C magnetic clutch malfunction
Misfire
Improper operation of torque converter clutch control (AT)
Loose installation of engine mounts
WARNING:
The following troubleshooting flow chart contains 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 REPAIR PROCEDURE" and "AFTER REPAIR PROCEDURE" described in this article.
  (See BEFORE REPAIR PROCEDURE .)
  
  (See AFTER REPAIR PROCEDURE .)
CAUTION:
- Disconnecting/connecting quick release connector without cleaning it may possibly 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.