Air/Fuel Mixture: Adjustments

Typical CO Measuring Port (Single Manifold Shown):

CHECKING CO ONLY

1. Warm the engine to normal operating temperatures.
2. With the engine "OFF" disconnect the DME control unit which is located in the glove box for 10 sec. Reconnect the DME control unit.

NOTE: Disconnecting the DME control unit will erase all existing fault codes. It is recommended that the fault memory be called up prior to the this operation, refer to COMPUTERIZED ENGINE CONTROLS.
Because the DME control unit is designed to adapt to minor idle and CO variations this test must be accomplished as quickly as possible to attain accurate CO values. Adaptation will begin soon after the engine has been restarted.

3. Disconnect the oxygen sensor harness connector located on the bracket at the rear of the transmission.
4. Remove the CO port bolts (one on each manifold) on the exhaust manifolds and connect an appropriate exhaust gas analyzer to the CO ports and restart the engine.
5. Allow the CO and HC values to stabilize.

^ The CO should be between 0.2 - 1.2% at idle speed.

6. Reassemble in reverse manner.

The air/fuel mixture is electronically controlled and can not be adjusted. If the air/fuel mixture is not within specification check for:

^ Intake system or crankcase air leaks
^ Faulty fuel injectors
^ Incorrect fuel pressure
^ Fault codes, refer to COMPUTERIZED ENGINE CONTROLS