Idle Speed & Ignition Timing

Ensure idle speed and base ignition timing are set to specification. Refer to the IDLE SPEED SPECIFICATIONS table and the IGNITION TIMING table in this article. Also, if necessary, refer to the ADJUSTMENTS article.

IDLE SPEED SPECIFICATIONS ⁽¹⁾

Application

Idle RPM

With A/C Off

750-850

With A/C On

⁽²⁾ 950-1050

⁽¹⁾	Transaxle/transmission in Neutral or Park.

⁽²⁾	With auto. transmission in gear, idle RPM is 750-850.

IGNITION TIMING - (Degrees BTDC @ RPM) ⁽¹⁾

Application

Man. Trans.

Auto. Trans.

MFI

⁽³⁾ 4-6 @ 800

TBI

⁽²⁾ 7-9 @ 800

⁽¹⁾	See Fig 1 for timing mark location.

⁽²⁾	With jumper wire installed between "C" and "D" terminals of test connector, near battery.

⁽³⁾	With jumper wire installed between "D" and "E" terminals of test connector, located near battery.

Fig 1: Locating Ignition Timing Mark (Typical)

Courtesy of GENERAL MOTORS CORP.