Synchronous Injection
When starting the engine, the fuel injectors inject the fuel simultaneously and synchronously at every camshaft position (CMP) sensor signal. When the engine is starting at a cold state, the amount of fuel is determined by the engine coolant temperature (ECT) sensor and is divided and injected.
Once the engine is running, the fuel injection occurs in a cylinder only when the cylinder is in the exhaust stroke. The powertrain control module (PCM) detects the compression stroke of cylinder 1 through the CMP sensor signal.