Suction pipe pressure detection apparatus

Abstract

Disclosed is a suction pipe pressure detection apparatus for detecting suction pipe pressure of a multi-cylinder type internal combustion engine provided with a throttle valve in the suction pipe of each of the cylinders, or a so-called independent suction type internal combustion engine. The apparatus detects the suction pipe pressure for just a few cylinders out of the total number of cylinders, makes proper corrections to the detected data in accordance with the throttle valve opening, engine speed of the internal combustion engine, etc., and, during the period before the next detection of the suction pipe pressure is made, accurately computes, using the above data, the suction pipe pressure for the cylinders, under the suction stroke, for which the pressure is not actually detected. That is, the throttle opening and the engine speed of the internal combustion engine are detected at intervals of shorter periods of time than those intervals at which the suction pipe pressure is actually detected, and correction is continuously made to the earlier detected suction pipe pressure according to the above detected data. The present invention enables a high-degree controlling of the internal combustion engine by making highly accurate suction pipe pressure data available at rather high frequency, and by further continually providing the intake air quantity, and the fuel injection amount, with considerable high accuracy.