Mercury Optimax Models 135, 150, Direct Fuel Injection., Page 63Get this manual
IGNITION
Manifold Absolute Pressure (MAP) Sensor
The MAP sensor is mounted between the cylinder headsA vacuum hose connects the map sensor to the intake manifoldThe ECM regulates fuel flow, in part, based on manifold absolute pressureDrawing vacuum on the MAP sensor hose will create lean fuel condition
Air Temperature Sensor
The air temperature sensor is mounted on the intake manifoldThe ECM regulates fuel flow, in part, based on manifold air temperatureAs air temperature increases, the ECM decreases fuel flow
Direct Injectors
6 direct injectors (1 per cylinder) are used to inject fuelair mix into cylindersInjectors are mounted between fuel rails and cylinder heads
Direct Injector Ohm Test (Injector Lead Disconnected)