APPARATUS AND METHOD FOR MEASURING THE RELATIVE EXHAUST BACK-PRESSURE OF AN INTERNAL COMBUSTION ENGINE

摘要

The exhaust back-pressure of an internal combustion (IC) engine is used to provide an indication of the relative combustion efficiency of the engine's cylinders. The instantaneous values of back-pressure are sensed at selected, sub-cyclic crankshaft angular intervals, within a full engine cycle, each angle interval being substantially less than that associated with a cylinder sub-cycle, each sensed value of back-pressure being identified by the sensed angle position to provide an indication of the sub-cyclic fluctuation in back-pressure as they occur at known cylinder exhaust stroke cycles within the engine cycle, thereby providing identification of each sub-cyclic back-pressure pulse as being associated with a particular engine cylinder, the relative magnitudes of the back-pressure pulses being compared with each other to provide indices of the relative combustion efficiency of each cylinder.