Fuel Injection

Stop Screw Plug Removal:

NOTE: The throttle stop screw, which controls minimum idle speed, is adjusted at the factory and covered with a plug to discourage unnecessary adjustment. Normally, it should not be necessary to adjust unless the throttle body is replaced.

To gain access to the throttle stop screw, pierce the plug with an awl, and apply leverage as illustrated to remove the plug.

ADJUSTMENT:

NOTE: Tool Required: TECH 1 Scan tool or equivalent.

1. Back idle stop screw out until there is an air gap between the screw and the throttle lever.

2. Turn the screw in until it just touches the throttle lever.

3. Turn the screw in an additional 1 1/2 turns.

4. Refer to IDLE LEARN PROCEDURE. The ECM will need to relearn the IAC valve position if the battery was disconnected.

5. Connect a scan tool to the ALDL connector.

6. Place transmission in "PARK" (A/T) or "Neutral" (MAN).

7. START engine and allow it to reach normal operating temperature about 90~C (194~F) and "Closed Loop".

8. Observe Idle Air Control (IAC) counts displayed on the "Scan" tool.

9. With the engine stabilized, IAC valve position should be 10-20 counts. If not repeat procedure. Observe "counts" on scan tool with all accessories "OFF" and the transmission in PARK or NEUTRAL. Also make sure the engine cooling fan is "OFF." Also make sure the throttle and cruise control cables do not hold open throttle valve.