INTERNAL COMBUSTION ENGINE CONTROL UNIT

摘要

PROBLEM TO BE SOLVED: To improve a capability to remove deposits adhering to an injection tip of a fuel injection valve without degrading fuel economy.SOLUTION: If continuous operation time in a deposit region in which deposits are possibly attached and accumulated onto an injection tip of a fuel injection valve is equal to or longer than predetermined time T1, a compression ratio is reduced down to a predetermined low compression ratio &egr;1 (S3). It is thereby possible to improve a capability to remove the deposits adhering to the injection tip of the fuel injection valve without degrading fuel economy. If it is determined that deposits adhere to the injection tip of the fuel injection valve even after the compression ratio is reduced down to the low compression ratio &egr;1 (S4), a fuel pressure is raised up to a high fuel pressure P1 (S6).SELECTED DRAWING: Figure 4