Engine Intake Ice Inference for Accurate Misfire Diagnosis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing engine misfire diagnostic systems often incorrectly indicate faults due to ice buildup in the throttle body and intake manifold during cold weather, leading to unnecessary delays in misfire diagnosis and maintenance requirements.
Innovation Solution
The system infers ice formation and melting based on engine operating parameters, enabling misfire diagnostics only after confirmation of ice dissipation, and couples engine heat to facilitate ice melting and dissipation, ensuring timely and accurate diagnosis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If misfire diagnosis is delayed for a predetermined time after engine start to allow ice to melt, then false misfire indications are reduced, but unnecessary delays in misfire diagnosis occur when ice has already melted and dissipated
Solution Approach 1:
The system performs preliminary detection of ice formation conditions during engine operation before shutdown. By monitoring temperature, humidity, and operating parameters during cold weather cruising conditions, the system determines ice formation likelihood in advance, then adjusts misfire diagnosis timing accordingly when the engine restarts, avoiding unnecessary delays.
Solution Approach 2:
The system uses feedback from temperature sensors, humidity sensors, and operating parameter monitors to continuously assess ice formation and dissipation conditions. This feedback loop allows the misfire diagnosis routine to adapt its timing based on real-time conditions, delaying diagnosis only when melt water is still present rather than using a fixed predetermined delay.
2Reliability
If ice buildup is detected and engine speed is increased to reduce sensitivity to poor air/fuel mixtures, then misfire effects are mitigated, but the underlying ice problem and false misfire indications remain unaddressed
Solution Approach 1:
The system extracts and isolates the ice-related misfire condition from general misfire diagnostics. By separately detecting ice formation conditions through temperature and humidity monitoring, the system can distinguish ice-induced misfires from actual engine problems, preventing false fault indications while maintaining the ability to detect real misfire issues.
Solution Approach 2:
The system introduces an intermediary ice detection and monitoring layer between the engine operation and misfire diagnosis. This intermediary routine monitors temperature, humidity, and operating parameters to determine ice formation, then modulates the misfire diagnosis routine accordingly, allowing both ice mitigation and accurate misfire detection.
3Reliability
If misfire diagnosis is delayed after engine start, then ice melt water effects are avoided, but the delay occurs even when no ice was formed or ice has already dissipated
Solution Approach 1:
The system makes the misfire diagnosis timing dynamic rather than static. Instead of a fixed predetermined delay, the diagnosis routine adapts its timing based on dynamic assessment of ice formation conditions, temperature, humidity, and estimated dissipation rates. This allows the system to enable rapid diagnosis when no ice is present while applying delays only when necessary.
Solution Approach 2:
The system changes the parameters used to determine misfire diagnosis timing based on environmental conditions. By monitoring temperature, humidity, engine operating parameters, and time since shutdown, the system adjusts the diagnosis enablement timing parameter dynamically, rather than using a constant delay period.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces unnecessary delays in misfire diagnosis and maintenance by ensuring diagnostics are only delayed when ice has melted and dissipated, thereby improving diagnostic accuracy and reducing false fault indications.
Implementation Method 1
Engine exhaust gases may blow by the pistons into the crankcase and are then vented into the throttle body or intake manifold through the PCV valve. The exhaust gases may contain water vapor which may freeze, especially in trucks during cold weather cruising conditions where cold air sweeping across the engine compartment may keep the throttle body and intake manifold below freezing temperatures.
Implementation Method 2
If ice remains during a subsequent engine start, it may melt and the resulting water may cause engine misfires until the water is cleared out.
Implementation Method 3
In still another aspect of the invention, the inventors have facilitated ice melting and dissipation by coupling engine heat to the intake manifold or throttle body.
Data Source
AI summary
Methods are provided for determining ice formation during cruising under cold weather conditions at the intake manifold or throttle body of an engine system and for enabling engine misfire diagnostics upon detection of dissipation of the formed ice.