Abstract: A spark-plug wire includes a boot of electrically insulative material defining a central bore configured to receive a spark plug, an electrical connector disposed in the central bore and configured to connect with the spark plug, and a cylindrical heat shield circumscribing the boot. The heat shield has retaining features extending past a distal end of the boot and configured to radially flex to engage with a hex of the spark plug to increase a retaining force of the spark-plug wire to the spark plug.

Abstract: Methods and systems are provided for controlling spark plug fouling in newly manufactured vehicles. In one example, an engine is operated with a first, more aggressive spark discharge schedule when in a pre-delivery state and transitioned to a second, less aggressive spark discharge schedule when in a post-delivery state. In each spark discharge schedule, a spark plug ignition coil is repeatedly discharged when the engine is off, such as when the engine is spinning down to rest on a shutdown event or before the engine is fueled on an engine restart event.

Abstract: Approaches for controlling dwell time in the ignition system of an internal combustion engine are provided. In one example, a method may include adjusting dwell based on engine operating conditions and further adjusting dwell in a manner proportional to existent spark plug conditions. By constantly assessing spark plug condition during operating of the internal combustion engine, premature wear of the spark plug may be prevented leading to an extension in the service life of spark plug and other ignition system components.

Abstract: Methods and systems are provided for detecting spark plug fouling and cleaning up fouled spark plug during pre-delivery phase of a vehicle. In one example, a method may include updating a spark plug fouling index saved in the non-volatile memory of the vehicle based on engine operating parameters, and indicating spark plug fouling based on the updated index. The method may further include cleaning the fouled spark plug by driving the vehicle along a planned route.

Abstract: Methods and systems are provided for addressing spark plug soot fouling. In one example, a method may include alternating one or more combustion events with spark timing advanced with one or more combustion events with nominal spark timing. The approach allows spark plug over-heating, and related issues such as knock, to be reduced.

Abstract: Approaches for controlling dwell time in the ignition system of an internal combustion engine are provided. In one example, a method may include adjusting dwell based on engine operating conditions and further adjusting dwell in a manner proportional to existent spark plug conditions. By constantly assessing spark plug condition during operating of the internal combustion engine, premature wear of the spark plug may be prevented leading to an extension in the service life of spark plug and other ignition system components.

Abstract: Methods and systems are provided for determining a type of spark plug fouling. In one example, a method may include differentiating spark plug fouling due to soot accumulation from spark plug fouling due to fuel additive accumulation based on a current on a control wire of the spark plug following application of a dwell command. Further, exhaust oxygen sensor degradation and/or exhaust catalyst degradation may be determined based on switching frequencies of one or more exhaust oxygen sensors and the type of spark plug fouling.

Abstract: Methods and systems are provided for controlling spark plug fouling in newly manufactured vehicles. In one example, an engine is operated with a first, more aggressive spark discharge schedule when in a pre-delivery state and transitioned to a second, less aggressive spark discharge schedule when in a post-delivery state. In each spark discharge schedule, a spark plug ignition coil is repeatedly discharged when the engine is off, such as when the engine is spinning down to rest on a shutdown event or before the engine is fueled on an engine restart event.

Abstract: Methods and systems are provided for addressing spark plug soot fouling. In one example, spark plug tip temperatures are raised and maintained elevated by advancing spark timing and increasing engine speed, while reducing an amount of EGR being delivered to the engine. The spark plug fouling mitigating actions are adjusted based on whether the engine is in a green condition at an assembly plant or not.

Abstract: Methods and systems are provided for detecting spark plug fouling and cleaning up fouled spark plug during pre-delivery phase of a vehicle. In one example, a method may include updating a spark plug fouling index saved in the non-volatile memory of the vehicle based on engine operating parameters, and indicating spark plug fouling based on the updated index. The method may further include cleaning the fouled spark plug by driving the vehicle along a planned route.

Abstract: Methods and systems are provided for controlling spark plug fouling in newly manufactured vehicles. In one example, a method may include operating an engine with a first direct injection fueling strategy including single intake direct injection on an engine start when in a pre-delivery state, and transitioning to a second different direct injection fueling strategy including split direct injection on the engine start when in a post-delivery state. In this way, spark plug fouling may be avoided in newly manufactured vehicles.

Abstract: Methods and systems are provided for determining a type of spark plug fouling. In one example, a method may include differentiating spark plug fouling due to soot accumulation from spark plug fouling due to fuel additive accumulation based on a current on a control wire of the spark plug following application of a dwell command. Further, exhaust oxygen sensor degradation and/or exhaust catalyst degradation may be determined based on switching frequencies of one or more exhaust oxygen sensors and the type of spark plug fouling.

Abstract: Methods and systems are provided for determining a type of spark plug fouling. In one example, a method may include differentiating spark plug fouling due to soot accumulation from spark plug fouling due to fuel additive accumulation based on a current on a control wire of the spark plug following application of a dwell command. Further, exhaust oxygen sensor degradation and/or exhaust catalyst degradation may be determined based on switching frequencies of one or more exhaust oxygen sensors and the type of spark plug fouling.

Abstract: Methods and systems are provided for inferring spark plug fouling due to accumulation of fuel additives thereon. In one example, an engine controller may infer spark plug hot fouling based on higher than expected exhaust temperatures by correlating the elevated exhaust temperature with late combustion phasing due to additive accumulation. A confidence factor of the spark plug hot fouling detection may be enhanced based on data regarding concurrent misfire and/or pre-ignition events.

Abstract: Methods and systems are provided for adjusting an ignition energy provided to an engine cylinder upon reactivation from a VDE mode of operation. Ignition energy is increased by increasing an ignition coil dwell time and/or an ignition coil strike frequency. The increased ignition energy improves combustion stability during the transition out of the VDE mode of operation.

Abstract: Methods and systems are provided for detecting spark plug fouling in an ignition system of an engine. In one example, a method may include directing current flow into a primary winding of an ignition coil of the ignition system for a duration of dwell period responsive to a dwell command from a controller, reducing the current flow to discharge an initial spark, and discharging additional sparks. The method may further include selectively generating an indication of a recommendation to change one or more spark plugs of the ignition system based upon a primary current measured after the dwell period.

Abstract: Methods and systems are provided for addressing spark plug soot fouling. In one example, spark plug tip temperatures are raised and maintained elevated by advancing spark timing and increasing engine speed, while reducing an amount of EGR being delivered to the engine. The spark plug fouling mitigating actions are adjusted based on whether the engine is in a green condition at an assembly plant or not.

Abstract: Methods and systems are provided for addressing spark plug soot fouling. In one example, a method may include alternating one or more combustion events with spark timing advanced with one or more combustion events with nominal spark timing. The approach allows spark plug over-heating, and related issues such as knock, to be reduced.

Abstract: Methods and systems are provided for inferring spark plug fouling due to accumulation of fuel additives thereon. In one example, an engine controller may infer spark plug hot fouling based on higher than expected exhaust temperatures by correlating the elevated exhaust temperature with late combustion phasing due to additive accumulation. A confidence factor of the spark plug hot fouling detection may be enhanced based on data regarding concurrent misfire and/or pre-ignition events.

Abstract: Methods and systems are provided for inferring spark plug fouling due to accumulation of fuel additives thereon. In one example, an engine controller may infer spark plug fouling due to accumulation of fuel additive based on a combination of engine operating parameters correlated with spark plug health. For example, the engine operating parameters may include a change in an adaptive knock term, an engine pre-ignition rate, and engine exhaust oxygen sensor switching frequency over a vehicle drive cycle, and an engine misfire rate.