Idle Mixture
- Start and warm engine to normal operating temperature (needle is in middle of coolant gauge). Open engine compartment hood and run engine at 2000 RPM for 2 minutes.
- Perform self-diagnostic procedure and check for smooth engine operation. Check ignition timing. With ignition timing correctly set, locate ECU behind right kick panel and set ECU into Mode II. Refer to G - TESTING W/CODES article.
- Maintain engine speed at 2000 RPM, under no load. Red LED on ECU should flash on and off more than 5 times in 10 seconds. If LED flashes, go to step 4). If LED does not flash, proceed to step 5).
- If LED flashes, but less than 5 times in 10 seconds, replace O2 sensor and perform test again. If LED still does not flash more than 5 times in 10 seconds, go to next step.
- If Red LED did not flash, turn engine off and check O2 sensor circuit. See Code 33 under TESTS W/CODES
or I - SYSTEM/COMP TEST article. Check fuel pressure regulator, airflow meter and its circuit, fuel injectors and its circuit, engine temperature sensor and its circuit or ECU function by substituting with a known good ECU.
IDLE SPEED & CO LEVEL
| Application |
Idle RPM |
CO Level |
| AAC Connected |
750-850 |
0.2-8.0% |
| AAC Disconnected |
700 |
0.2-8.0% |