Fuel Injector Diagnostics via Pump Control and Pressure Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel injector diagnostic systems face challenges in accurately diagnosing injector faults when the engine is running, due to high fuel rail pressures and pressure fluctuations, which can lead to increased emissions and decreased fuel economy.
Innovation Solution
A fuel injector diagnostic system comprising a fuel pump control module, a pressure sensor, and a diagnostic module that measures fuel rail pressures before and after an injection event while the engine is running, allowing for fault diagnosis based on pressure differences, even at high engine loads and idling conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fuel pressure is measured at low pressure when engine is shut off, then measurement errors are reduced, but multiple injection events are required to ensure accurate measurement
Solution Approach 1:
The system changes the operating parameters by disabling the fuel pump during diagnosis to create low-pressure conditions, enabling accurate single-shot pressure measurements without requiring multiple injection events. This parameter change allows the system to achieve both measurement precision and time efficiency.
2Productivity
If fuel pressure is measured at high pressure when engine is running, then diagnosis can be performed during operation, but pressure fluctuations cause measurement errors
Solution Approach 1:
The system performs preliminary action by disabling the fuel pump before measuring pressure to establish a stable baseline state. This preliminary action eliminates pressure fluctuations during the measurement process, enabling accurate measurements while maintaining the ability to diagnose during engine operation.
Solution Approach 2:
The system implements periodic action by cycling the fuel pump on and off in a controlled sequence - disabling it during measurement phases and enabling it during normal operation. This periodic control allows the system to alternate between stable measurement conditions and operational conditions, achieving both accuracy and availability.
3Measurement precision
If multiple injection events are performed on the same injector, then accurate fuel pressure measurement is ensured, but fuel consumption increases and emissions increase
Solution Approach 1:
By changing the fuel pump operation parameter to disabled state during diagnosis, the system enables accurate pressure measurements in a single injection event rather than requiring multiple events. This parameter change reduces the total fuel quantity consumed during diagnosis, thereby reducing emissions while maintaining measurement precision.
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
Enables accurate and efficient fault diagnosis of fuel injectors during engine operation, reducing the need for multiple injection events and minimizing pressure fluctuations, thereby improving fuel economy and emission control.
Implementation Method 1
The pressure sensor measures a first pressure of the fuel rail before an injection event and a second pressure of the fuel rail after the injection event
Data Source
AI summary
A fuel injector diagnostic system includes a fuel pump control module, a pressure sensor, and a diagnostic module. The fuel pump control module disables delivery of fuel to a fuel rail of an engine. The pressure sensor measures a first pressure of the fuel rail before an injection event and a second pressure of the fuel rail after the injection event on at least one of a plurality of injectors when the engine is running. The diagnostic module diagnoses a fault in the at least one of the injectors based on the first pressure and the second pressure.