Fuel injection control

An engine includes an electronic controller which samples the pressure in the induction system once per rotation of the crankshaft. The controller is configured to determine the minimum voltage signal output by the pressure sensor. The controller then uses the minimum pressure sensed by the pressure sensor to control the fuel injection of the engine. The controller may include two and/or three dimensional maps for predicting the appropriate timing for sampling the pressure sensor. Optionally, the controller may include a bottom hold device for holding a minimum value of the signal output from the pressure sensor, thus corresponding to the minimum pressure sensed by the pressure sensor.