Methods and system for diagnosing a high-pressure fuel pump in a fuel system
AssigneeTransportation IP Holdings, LLC
InventorsMorse N. Taxon, Pradheepram Ottikkutti
Life of this patent
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Abstract
Various methods and systems are provided for health assessments of a fuel system. In one example, a fuel system includes a high-pressure fuel pump operable to increase fuel pressure from a first pressure to a second pressure, a common fuel rail fluidly coupling the high-pressure fuel pump to a plurality of fuel injectors each of which is operable to inject fuel to individual cylinders of an engine, a pressure sensor operable to detect a pressure of fuel at the common fuel rail, and a controller operable to diagnose a condition of the high-pressure fuel pump based on output from the pressure sensor.
Claims20
A method, comprising:
- diagnosing a degradation condition of a high-pressure fuel pump based on feedback from a pressure sensor positioned downstream of the high-pressure fuel pump;
- and
- differentiating a change in performance between the degradation condition of the high-pressure fuel pump and degradation due to a fuel flow control valve upstream of the high-pressure fuel pump by:
- diagnosing the degradation of the fuel flow control valve by supplying a plurality of diagnostic current values to the fuel flow control valve, determining if a target pressure is reached in response to the diagnostic current values, and comparing expected pressures of the diagnostic current values to measured pressures;
- and
- adjusting one or more engine operating parameters based on the condition.
A method for a fuel system comprising a fuel pump operable to increase fuel pressure from a first pressure to a second pressure, the fuel pump including a plurality of pumping chambers, each pumping chamber including a piston actuatable by one or more cam lobes coupled to a common pump drive shaft, and each pumping chamber further including a respective check valve, a common fuel rail fluidly coupled to the fuel pump and to at least one fuel injector, and the fuel injector is operable to inject fuel to a cylinder of an engine, and a pressure sensor operable to detect a pressure of fuel in the common fuel rail, the method comprising:
- receiving an output pressure signal from the pressure sensor;
- determining a plurality of peak magnitudes of the output pressure signal, each peak magnitude corresponding to a pumping action of a respective pumping chamber of the plurality of pumping chambers;
- diagnosing a condition of the fuel pump based at least in part on the determined plurality of peak magnitudes;
- and
- differentiating a change in performance between degradation due to a fuel flow control valve upstream of the fuel pump and degradation of the fuel pump.
A fuel system controller configured to:
- receive an output pressure signal from a pressure sensor;
- determine a plurality of peak magnitudes of the output pressure signal, each peak magnitude corresponding to a pumping action of a fuel pump;
- diagnose a condition of the fuel pump based at least in part on the determined plurality of peak magnitudes;
- and
- differentiate a change in performance between degradation due to a fuel flow control valve upstream of the fuel pump and degradation of the fuel pump.
Dependencies are inferred from the claim text.