Detection and identification of fuel injector failure modes
A fuel system includes including a fuel rail configured to receive fuel from a fuel supply and to supply fuel to a plurality of fuel injectors. A pressure sensor is operatively coupled with and configured to sense pressure of fuel in the fuel rail. An exhaust oxygen sensor operatively coupled with and configured to sense oxygen content of exhaust output by the engine. An electronic control system is configured to receive a fuel pressure signal from the pressure sensor, detect a predetermined frequency of the pressure signal, receive an exhaust oxygen signal from the exhaust oxygen sensor, and in response to an output of the resonating filter and the exhaust oxygen signal, diagnose one of an under-fueling failure mode and an over-fueling failure mode of a diagnosed injector of the plurality of injectors.
1 . A system comprising:
an engine including a plurality of cylinders;
a fuel system configured to supply fuel to the plurality of cylinders, the fuel system including a fuel rail configured to receive fuel from a fuel supply and to supply fuel to a plurality of fuel injectors,
a pressure sensor operatively coupled with and configured to sense pressure of fuel in the fuel rail,
an exhaust oxygen sensor operatively coupled with and configured to sense oxygen content of exhaust output by the engine, and
and an electronic control system operatively coupled with the engine, the plurality of fuel injectors, the pressure sensor, and the exhaust oxygen sensor, the electronic control system being configured to:
receive a fuel pressure signal from the pressure sensor,
detect a predetermined frequency of the pressure signal,
receive an exhaust oxygen signal from the exhaust oxygen sensor, and
in response to the predetermined frequency and the exhaust oxygen signal, diagnose one of an under-fueling failure mode and an over-fueling failure mode of a diagnosed injector of the plurality of injectors.
2 . The system of claim 1 , wherein the electronic control system is configured to:
determine an average of an absolute value of an output of a resonating filter;
diagnose the under-fueling failure mode in response to the average satisfying a predetermined criterion and the exhaust oxygen signal satisfying a first predetermined criterion; and
diagnose the under-fueling failure mode in response to the average satisfying the predetermined criterion and the exhaust oxygen signal satisfying a second criterion differing from the first criterion.
3 . The system of claim 2 , wherein:
the first predetermined criterion comprises the exhaust oxygen signal being below a first predetermined threshold, and
the second predetermined criterion comprises the exhaust oxygen signal being above a second predetermined threshold.
4 . The system of claim 3 , wherein the first predetermined threshold and the second predetermined threshold are determined for stoichiometric fuel combustion.
5 . The system of claim 1 , wherein the electronic control system is configured to:
process the pressure signal with a plurality of resonating filters configured to resonate in response to a plurality of different injector failure modes; and
differentially diagnose one of the plurality of different injector failure modes in response to output of one or more of the plurality of resonating filters.
6 . The system of claim 1 , wherein the system distinguishes between an under fueling condition of a first injector and an over-fueling condition of a second injector adjacent the first injector in firing order in response to the exhaust oxygen signal.
7 . The system of claim 1 , wherein the electronic control system is configured to identify the diagnosed injector in response to a phase of the predetermined frequency.
8 . A process comprising:
operating a fuel system to supply fuel to an internal combustion engine, the fuel system including a fuel rail configured to receive fuel from a fuel supply and to supply fuel to a plurality of fuel injectors, a pressure sensor operatively coupled with and configured to sense pressure of fuel in the fuel rail, an exhaust oxygen sensor, and an electronic control system operatively coupled with the engine, the plurality of fuel injectors, the pressure sensor, and the exhaust oxygen sensor; and
operating the electronic control system to:
receive a fuel pressure signal from the pressure sensor,
process the pressure signal with a resonating filter,
receive an exhaust oxygen signal from the exhaust oxygen sensor, and
in response to an output of the resonating filter and the exhaust oxygen signal, diagnose one of an under-fueling failure mode and an over-fueling failure mode of an injector of the plurality of injectors.
9 . The process of claim 8 , comprising operating the electronic control system to:
determine an average of an absolute value of an output of the resonating filter;
diagnose the under-fueling failure mode in response to the average satisfying a predetermined criterion and the exhaust oxygen signal satisfying a first predetermined criterion; and
diagnose the under-fueling failure mode in response to the average satisfying the predetermined criterion and the exhaust oxygen signal satisfying a second criterion differing from the first criterion.
10 . The process of claim 9 , wherein:
the first predetermined criterion comprises the exhaust oxygen signal being below a first predetermined threshold, and
the second predetermined criterion comprises the exhaust oxygen signal being above a second predetermined threshold.
11 . The process of claim 10 , wherein the first predetermined threshold and the second predetermined threshold are determined for stoichiometric fuel combustion.
12 . The process of claim 8 , comprising operating the electronic control system to:
process the pressure signal with a plurality of resonating filters configured to resonate in response to a plurality of different injector failure modes; and
differentially diagnose one of the plurality of different injector failure modes in response to output of one or more of the plurality of resonating filters.
13 . The process of claim 12 , wherein the process distinguishes between an under fueling condition of a first injector and an over-fueling condition of a second injector adjacent the first injector in firing order in response to the exhaust oxygen signal.
14 . The process of claim 8 , comprising operating the electronic control system to identify the diagnosed injector in response to a phase of the output of the resonating filter.
15 . An electronic controller apparatus comprising:
a processor; and
a non-transitory memory medium configured instructions executable by the processor to:
receive a fuel pressure signal from a pressure sensor,
process the pressure signal with a resonating filter,
receive an exhaust oxygen signal from the exhaust oxygen sensor, and
in response to an output of the resonating filter and the exhaust oxygen signal, diagnose one of an under-fueling failure mode and an over-fueling failure mode of an injector of a plurality of injectors.
16 . The electronic controller apparatus of claim 15 , wherein the non-transitory memory medium is configured with instructions executable by the processor to:
determine an average of an absolute value of an output of the resonating filter;
diagnose the under-fueling failure mode in response to the average satisfying a predetermined criterion and the exhaust oxygen signal satisfying a first predetermined criterion; and
diagnose the under-fueling failure mode in response to the average satisfying the predetermined criterion and the exhaust oxygen signal satisfying a second criterion differing from the first criterion.
17 . The electronic controller apparatus of claim 16 , wherein:
the first predetermined criterion comprises the exhaust oxygen signal being below a first predetermined threshold, and
the second predetermined criterion comprises the exhaust oxygen signal being above a second predetermined threshold.
18 . The electronic controller apparatus of claim 17 , wherein the first predetermined threshold and the second predetermined threshold are determined for stoichiometric fuel combustion.
19 . The electronic controller apparatus of claim 15 , wherein the non-transitory memory medium is configured with instructions executable by the processor to:
process the pressure signal with a plurality of resonating filters configured to resonate in response to a plurality of different injector failure modes; and
differentially diagnose one of the plurality of different injector failure modes in response to output of one or more of the plurality of resonating filters.
20 . The electronic controller apparatus of claim 19 , wherein the electronic controller apparatus distinguishes between an under fueling condition of a first injector and an over-fueling condition of a second injector adjacent the first injector in firing order in response to the exhaust oxygen signal.