Mercury Optimax Models 135, 150, Direct Fuel Injection., Page 167Get this manual
DIRECT FUEL INJECTION
Compressor Notes: To aid in starting when the air rail pressure is low and before the compressor has time to build pressure, the direct injector is held open by the ECMThis allows the compression from inside the cylinders to pressurize the air rail faster (1 or strokes, or 600 of crankshaft rotation)Idle Notes: Idle quality is controlled by fuel volume and fuel timingThe throttle shutters will be open at idle speedsThe shift cut-out switch will interrupt the fuel to of the cylinders to assist in shiftingThe TPS signals the ECM to change the fuel and spark without movement of the throttle shuttersThe throttle cam is manufactured to allow the TPS sensor shaft to move before opening the throttle shuttersThe crankshaft position sensor is different from the standard 3.0 liter sensorThe crank position sensor serves two functions (flywheel speed and position)