Mercury Mariner 200, 225 Optimax Outboards Service Manual, 90-855348, Page 57Get this manual
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
Disconnecting Harness Connectors from Ignition Coils andor Injectors
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 headsaWire Clip (push center down to remove)
Direct Injector Ohm Test (Injector Lead Disconnected)
Connect meter leads between each injector terminal pin
1998 EPA Certified