IGNITION
90-855347R1 JANUARY 1999 Page 2A-9
Manifold Absolute Pressure (MAP) Sensor
The MAP sensor is mounted between the cylinder heads. A vacuum hose connects the
map sensor to the intake manifold. The ECM regulates fuel flow, in part, based on man-
ifold absolute pressure. Drawing a vacuum on the MAP sensor hose will create a lean fuel
condition.
Air Temperature Sensor
The air temperature sensor is mounted on the intake manifold. The ECM regulates fuel
flow, in part, based on manifold air temperature. As air temperature increases, the ECM
decreases fuel flow.
Direct Injectors
6 direct injectors (1 per cylinder) are used to inject a fuel/air mix into cylinders. Injectors
are mounted between fuel rails and cylinder heads.
Direct Injector Ohm Test (Injector Lead Disconnected)
Connect meter leads between each in-
jector terminal pin.
1 - 1.6
Fuel Injectors
6 fuel injectors (1 per cylinder) are used to provide fuel from the fuel rail to the direct injec-
tors. The fuel injectors are mounted in the fuel rail.
Fuel Injector Ohm Test (Injector Lead Disconnected)
Connect meter leads between each in-
jector terminal pin.
1.7 - 1.9
Disconnecting Harness Connectors from Ignition Coils and/or Injectors
54871
a
a-Wire Clip (push center down to remove)
Troubleshooting
The ECM is designed such that if a sensor fails, the ECM will compensate so that the en-
gine does not go into an over-rich condition.
Disconnecting a sensor for troubleshooting purposes may have no noticeable effect.
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