| 摘要 |
PROBLEM TO BE SOLVED: To provide a common rail type fuel injection system capable of detecting accurately common rail pressure, and capable of detecting reliably opening and closing of a safety valve. SOLUTION: A fuel injection system detects common rail pressure from a detection signal of a pressure sensor, and determines whether the detected value falls in an abnormal range or not (S100). When the fuel injection system determines that the common rail pressure falls in the abnormal range, a target injection quantity is set at a smaller value than a value to be set when the common rail pressure falls in the normal range (S102). When the system determines that the common rail pressure falls in the normal range, a value is set depending on an operating state and a cooling water temperature (S104). After setting a target injection quantity, the fuel injection system executes P/L valve opening determination processing. In the P/L valve opening determination processing, the opening/closing of a pressure limiter is detected based on a leaked quantity of fuel calculated from a difference in common rail pressures before and after fuel injection. The sensing range of the pressure sensor is set at a pressure range including a part of the abnormal range and the normal range of common rail pressure. COPYRIGHT: (C)2008,JPO&INPIT
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