No. 4 Hard To Start/Long Crank/Erratic Start/Erratic Crank: Notes
WARNING: This page is about a different car, the 2016 Mazda CX-5. However, it is still accessible from the selected car via links, so may be relevant.
| 4 |
HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK |
| DESCRIPTION |
- Starter cranks engine at normal speed but engine requires excessive cranking time before starting.
- Battery is operating normally.
|
| POSSIBLE CAUSE |
NOTE:
- If the ignition is not switched off (to LOCK or ACC) after the engine stalls, and then an engine restart is attempted, the PCM corrects the difference between CKP sensor and CMP sensor signals caused by engine stalling, which may result in more time needed to restart the engine.
- Engine overheating
- PCM DTC is stored
- Erratic signal to PCM
- ECT sensor No. 1 or related circuit malfunction
- MAF sensor or related circuit malfunction
- MAP sensor or related circuit malfunction
- A/F sensor or related circuit malfunction
- HO2S or related circuit malfunction
- Improper air/fuel mixture ratio control
- Improper operation of drive-by-wire control system
- Incorrect fuel injection timing
- Fuel injector malfunction
- Purge solenoid valve malfunction
- Contamination in MAF sensor
- Under the condition in which the engine starts and stops repeatedly while the vehicle is not driven, the fuel injected prior to complete ignition during engine start may drop into the oil pan from the cylinder and mix with the engine oil. The situation in which excess quantities of fuel continue to be injected due to an engine coolant temperature signal error is the same.
- Intermittent open circuit in PCM ground circuit
- Poor fuel quality
- Fuel leakage
- Air leakage from intake-air system
- Intake-air system restriction
- Vacuum leakage
- Improper engine oil viscosity
- Erratic signal from CMP sensor
- Loose installation
- Damaged trigger wheel (intake camshaft and/or exhaust camshaft)
- Open or short circuit in related wiring harness
- Erratic signal from CKP sensor
- Loose installation
- Damaged trigger wheel (crankshaft pulley)
- Open or short circuit in related wiring harness
- Inadequate fuel pressure (high or low pressure side)
- Fuel pressure sensor malfunction
- High pressure fuel pump malfunction
- Spill valve control solenoid valve control circuit malfunction (damage to driver in PCM caused by short circuit to ground system)
- Spill valve control solenoid valve malfunction (built-into high pressure fuel pump)
- Relief valve (built-into high pressure fuel pump) malfunction
- Fuel line restriction
- Fuel filter clogged
- Fuel pump unit malfunction
- Starting system malfunction
- Low engine compression
- Improper intake valve timing
- Improper exhaust valve timing
- Spark plug malfunction
- Erratic signal to ignition coils
- Exhaust system or TWC restriction
- PCV valve malfunction
- Injector driver (built-into PCM) malfunction
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| POSSIBLE CAUSE |
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 SERVICE PRECAUTION" and "AFTER SERVICE PRECAUTION" described in this article. (See BEFORE SERVICE PRECAUTION
.) (See AFTER SERVICE PRECAUTION
.)
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 matter.
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CAUTION:
- Verify the malfunction symptom according to not only the PID value but also the symptom troubleshooting.