No. 4 Hard To Start/Long Crank/Erratic Start/Erratic Crank [MZI-3.7]: Notes

WARNING: This page is about a different car, the 2009 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

DESCRIPTION AND POSSIBLE CAUSE

4	HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK
DESCRIPTION	The starter cranks engine at normal speed but engine requires excessive cranking time before starting. The battery is in normal condition.
POSSIBLE CAUSE	Erratic signal to ignition coil Vacuum leakage Poor fuel quality Starting system malfunction Spark plug malfunction Air leakage from intake-air system Erratic signal from CKP sensor Erratic signal from CMP sensor Improper air/fuel mixture ratio control Air cleaner restriction Improper operation of electronic throttle control system PCV valve malfunction Inadequate fuel pressure Purge solenoid valve malfunction MAF sensor contamination Incorrect MAF sensor ground voltage Restriction in exhaust system Pressure regulator malfunction (built-in fuel pump unit) 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 [MZI-3.7] .) (See AFTER SERVICE PRECAUTION [MZI-3.7] .) 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.

HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK

DESCRIPTION

The starter cranks engine at normal speed but engine requires excessive cranking time before starting.
The battery is in normal condition.

POSSIBLE CAUSE

Erratic signal to ignition coil
Vacuum leakage
Poor fuel quality
Starting system malfunction
Spark plug malfunction
Air leakage from intake-air system
Erratic signal from CKP sensor
Erratic signal from CMP sensor
Improper air/fuel mixture ratio control
Air cleaner restriction
Improper operation of electronic throttle control system
PCV valve malfunction
Inadequate fuel pressure
Purge solenoid valve malfunction
MAF sensor contamination
Incorrect MAF sensor ground voltage
Restriction in exhaust system
Pressure regulator malfunction (built-in fuel pump unit)
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 [MZI-3.7] .)
  
  (See AFTER SERVICE PRECAUTION [MZI-3.7] .)
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.