摘要:
Methods and systems are provided for identifying and indicating degradation of an engine cylinder spark plug. In response to a cylinder misfire event during selected engine operating conditions, followed by an occurrence of a threshold number and/or rate of pre-ignition events in the same cylinder, a controller may determine that the spark plug is degraded. The controller may limit combustion in the cylinder in response to the degradation. Additionally, cylinder pre-ignition mitigating steps may be taken.
摘要:
A method for improving exhaust after treatment initial warm up during engine starting is presented. In one example, the method adjusts an engine air flow amount to a level where a desired substantially constant heat flux is provided by the engine to an exhaust after treatment device. The method may reduce fuel consumption and a need for a vacuum pump to provide vacuum to vacuum consumers of a vehicle during exhaust after treatment heating.
摘要:
A method for controlling differences in cylinder mixtures for a two cylinder bank engine having a turbocharger is presented. In one example, the description includes a method for adjusting valve timing to reduce cylinder mixture variation.
摘要:
A method for controlling engine vacuum production is disclosed. In one example, one or more air sources to an engine intake manifold are closed so as to increase an amount of air drawn from another air source. The method may increase a rate of vacuum supplied to a vacuum actuated device so as to improve operation of the vacuum actuated device.
摘要:
An engine with two vacuum sources is disclosed. In one example, a valve position is adjusted when engine load is low and intake manifold pressure is low to arbitrate vacuum between the two vacuum sources. The approach may increase engine operating efficiency during at least some conditions.
摘要:
A method for controlling differences in cylinder mixtures for a two cylinder bank engine having a turbocharger is presented. In one example, the description includes a method for adjusting valve timing to reduce cylinder mixture variation.
摘要:
A method for providing air to a combustion chamber of an engine, the engine including a compressor and a boost tank selectably coupled to an intake manifold. The method includes varying a relative amount of engine exhaust in air pressurized in the boost tank based on engine operating conditions, and discharging the air pressurized in the boost tank to the intake manifold.
摘要:
An engine with a two vacuum sources is disclosed. In one example, a valve position is adjusted in when engine load is low and intake manifold pressure is low to arbitrate vacuum between the two vacuum sources. The approach may increase engine operating efficiency during at least some conditions.
摘要:
A vacuum pump onboard a vehicle provides vacuum for a brake booster and to control the electronic vacuum regulation valve (EVRV) valve of a wastegate on a turbocharger. Commands to the EVRV are based on an operating condition of an engine and the vacuum level in the vacuum system. In one example, a vacuum sensor is provided to determine vacuum proximate the EVRV. In another example, the vacuum proximate the EVRV is modeled based on the vacuum at the brake booster, which may be determined by a vacuum sensor coupled to the brake booster.
摘要:
An engine with a fast vacuum recovery brake booster system is disclosed. In one example, an actuator is adjusted in response to a flow between the brake booster and an engine intake manifold. Operation of the engine and vehicle brakes may be improved especially when the engine is boosted.