Electronic control of engine fuel delivery

An electronic control system for an internal combustion engine that includes:

• an engine having at least one mechanism responsive to electronic control signals for affecting operation of the engine and at least one sensor for supplying electrical sensor signals in real time as a function of operating conditions at the engine,
• an electronic control unit including memory means having prestored wherein at least one look-up table of engine control parameters addressable as a function of engine condition signals, microprocessor-based control means including means for receiving said sensor signals, means for addressing said memory to obtain control parameters from said table as a function of said sensor signals, and means for generating said control signals to said mechanism as a preselected function of said control parameters, and
• means for selectively reprogramming said table comprising means for selectively reading and temporarily storing said table, means for displaying said table to an operator, means on said displaying means responsive to an operator for selectively identifying specific parameter entries in said table to be varied, means for varying said specific entries on said displaying means and in said temporarily-storing means, and means for downloading parameter entries varied by the operator into said memory table,
• said control means including means for employing said look-up table in said memory means to continue operation of the engine during reprogramming of said table.

In a method of controlling operation of an engine that comprises the steps of:

• (a) storing an electronic table of engine control parameters as addressable functions of engine operating conditions,
• (b) monitoring operating conditions at the engine,
• (c) periodically addressing said table as a function of said conditions to obtain at least one control parameter associated with current operating conditions at the engine, and
• (d) controlling at least one mechanism associated with the engine affecting operation at the engine as a function of said at least one control parameter associated with said current operating conditions,
• the improvement for selectively varying parameters in said table without interrupting operation at the engine comprising the steps of:
• (e) detecting a mode of operation in which parameters in said table are to be varied,
• (f) upon onset of said mode of operation, storing the at least one control parameter obtained in said step (c) and thereafter inhibiting said step (c) during duration of said mode of operation, and
• (g) employing in said step (d) said parameter stored in said step (f) during said mode of operation.

An electronic system for controlling fuel delivery to an internal combustion engine having at least one electronic fuel injector and a plurality of sensors for providing electronic sensor signals that vary as functions of operating conditions at the engine, said system comprising:

• an electronic memory having a multiplicity of injector pulse width control parameters prestored therein as a look-up table addressable as a function of said sensor signals,
• means for selectively varying said parameters in said table comprising means for displaying the entire said table to an operator, means on the display responsive to an operator for selectively identifying a table location at which the associated parameter is to be varied, means for selectively varying said associated parameter to a modified parameter on said display, and means responsive to the operator for replacing said associated parameter at said table location with said modified parameter, and
• an electronic controller including means for receiving said sensor signals, means for addressing said table as a function of said sensor signals to obtain a first pulse width control parameter associated with current operating conditions at the engine, means responsive to said selectively-varying means and to said parameter replacing means to store said first parameter and inhibit addressing of said table while said table parameters are being varied, and means for energizing said injector for a time duration that varies as a function of said first parameter.