Idle Speed

NOTE: Before adjusting idle speed, warm engine to normal operating temperature. Turn off all accessories. Place transmission in Neutral (M/T) or Park (A/T). DO NOT adjust idle using throttle adjusting screw. Throttle adjusting screw is preset and if adjusted, will adversely affect engine performance.

NOTE: On Miata, use Blue 1-pin connector located in right front corner of engine compartment as a source of battery power for positive lead of tachometer or timing light (battery is in trunk). DO NOT ground this connector, or 20-amp WIPER fuse will blow.

Connect New Generation Star (NGS) Tool (49 T088 0A0) to data link connector 2 located under left side of dash. See Figure . Using NSG tool, select PID/DATA MONITOR AND RECORD and monitor RPM. Connect Diagnostic Tool (49 B019 9A0) to data link connector. Set SYSTEM SELECT to position 1 and TEST SWITCH to SELF-TEST.
If idle speed is not within specification, rotate air adjusting screw on throttle body. See Fig 1 . See IDLE SPEED SPECIFICATIONS TABLE . Disconnect NGS tool from data link connector 2 and diagnostic tool from data link connector.

Fig 1: Rotating Air Adjusting Screw (Typical)

Courtesy of MAZDA MOTORS CORP.

IDLE SPEED SPECIFICATIONS

Application

RPM

M/T

850

A/T ⁽¹⁾

800

⁽¹⁾	Place automatic transmission in Park.