초록 ▼

Methods of utilizing engine 15 crankshaft acceleration 17 to monitor cold start spark retard are presented. A first method utilizes a variance in a crankshaft acceleration based deviation signal 21 and looks for changes in the variance to confirm if cold spark retard has occurred by the ignition sys

Methods of utilizing engine 15 crankshaft acceleration 17 to monitor cold start spark retard are presented. A first method utilizes a variance in a crankshaft acceleration based deviation signal 21 and looks for changes in the variance to confirm if cold spark retard has occurred by the ignition system. In a second method, a threshold level of a group of cylinder crankshaft acceleration deviation signals .DELTA., can be detected and compared to a level of crankshaft deviant acceleration when normal spark is commanded to determine if commanded spark retard has been realized.

대표청구항 ▼

1. A method to verify cold start spark retard in a reciprocating piston internal combustion engine comprising:measuring engine acceleration corresponding to each of a plurality of representative cylinder firings during operation of said engine; determining an average acceleration over a series of fi

1. A method to verify cold start spark retard in a reciprocating piston internal combustion engine comprising:measuring engine acceleration corresponding to each of a plurality of representative cylinder firings during operation of said engine; determining an average acceleration over a series of firings of said plurality of representative cylinder firings; determining deviation of each one of said representative cylinder firing accelerations from said average acceleration; determining a variance of said cylinder firing acceleration deviations; and comparing said variance of said cylinder firing acceleration deviations with a variance representative of spark retard condition to confirm the presence of spark retard.