No.4 Hard To Start/Long Crank/Erratic Start/Erratic Crank: 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.4 DESCRIPTION AND POSSIBLE CAUSE

4	HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK
DESCRIPTION	The starter cranks engine at the normal speed but the engine requires excessive cranking time before starting. The battery is in the normal condition.
POSSIBLE CAUSE	Vacuum leakage Air leakage from intake-air system Air suction at intake-air system (between MAF sensor and intake ports) Air cleaner restriction Improper operation of drive-by-wire control system Drive-by-wire control system operates in fail-safe mode Throttle body malfunction (stuck open) SSV stuck open SSV solenoid valve malfunction (stuck open) APV stuck open* APV motor malfunction* APV position sensor malfunction* Poor fuel quality Jet air mixing system malfunction (restriction or leakage in air passage) Inadequate fuel pressure Pressure regulator malfunction (integrated in fuel pump) Fuel injector (FP1) (RP1) is clogged. Open or short in fuel injector (FP1) (RP1) control signal circuit Restriction in exhaust system Purge solenoid valve malfunction (stuck open) Improper air/fuel ratio control (abnormal ECT signal to PCM) Erratic signal form eccentric shaft position sensor MAF sensor contamination (abnormal signal to PCM) MAF sensor improper installation 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 Starting system malfunction Spark leakage from high-tension leads Spark plug malfunction 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.

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

DESCRIPTION

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

POSSIBLE CAUSE

Vacuum leakage
Air leakage from intake-air system
Air suction at intake-air system (between MAF sensor and intake ports)
Air cleaner restriction
Improper operation of drive-by-wire control system
Drive-by-wire control system operates in fail-safe mode
Throttle body malfunction (stuck open)
SSV stuck open
SSV solenoid valve malfunction (stuck open)
APV stuck open*
APV motor malfunction*
APV position sensor malfunction*
Poor fuel quality
Jet air mixing system malfunction (restriction or leakage in air passage)
Inadequate fuel pressure
Pressure regulator malfunction (integrated in fuel pump)
Fuel injector (FP1) (RP1) is clogged.
Open or short in fuel injector (FP1) (RP1) control signal circuit
Restriction in exhaust system
Purge solenoid valve malfunction (stuck open)
Improper air/fuel ratio control (abnormal ECT signal to PCM)
Erratic signal form eccentric shaft position sensor
MAF sensor contamination (abnormal signal to PCM)
MAF sensor improper installation
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
Starting system malfunction
Spark leakage from high-tension leads
Spark plug malfunction
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.