Automotive Troubleshooting Engine Starting Condition Inspection

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Purpose of inspection
The cause of malfunctions related to engine starting differs depending on whether the initial combustion occurs or not, or whether starting takes too much time or not. Therefore, inspect the engine starting condition to determine the cause of the malfunction.

Inspection method
Crank the engine to check the engine starting condition.
Criteria (gasoline engine)
1. No initial combustion, does not start
One of the three engine elements (that affect engine performance) may have caused a malfunction.
2. Takes time to start
Based on the fact that the engine can start, the three engine elements can be judged as normal. Therefore, the malfunction may be caused by the air fuel ratio when starting.
3. Initial combustion occurs but immediately stalls
The ignition system and the compression system can be judged as normal. Also, the fuel system can be judged as normal only when the engine starts. Therefore, the malfunction may be caused by a drop in fuel pressure, ISCV (Idle Speed Control Valve), etc.
If the malfunction is caused by the ISCV opening, starting while depressing the accelerator pedal maintains the amount of intake air and the engine runs without stalling.
Criteria (diesel engine)
1. No initial combustion, does not start
Takes a long time to start
The malfunction may be caused by one of the three engine elements.
In the fuel system, a malfunction of the injection timing will not cause engine starting to become diffi cult.
2. Initial combustion occurs but immediately stalls
The glow system and compression system can be judged as normal. The fuel system can be judged to be normal only when the engine starts. Therefore, the malfunction may be caused by the injection pump operation when the engine is idle.

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