Engine Controls - Adjustments - 2.3L: Other Mazda Millenia I

ENGINE MECHANICAL

Before performing any on-vehicle adjustments to fuel or ignition systems, ensure engine mechanical condition is okay.

VALVE CLEARANCE CHECK

1. Remove intake manifold and valve covers. See appropriate engines article in ENGINES. Ensure engine is cold. Rotate crankshaft clockwise until No. 1 piston is at TDC of compression stroke. Measure valve clearance between camshaft lobe and valve tappet of both banks at "A". (Scheme 2) If clearance is not within specification, replace adjustment shim. See «VALVE CLEARANCE SPECIFICATIONS»(ref-18649-S29105435342000123000000) table.
2. Rotate crankshaft clockwise about 240 degrees positioning No. 3 piston at TDC of compression stroke. Measure valve clearance between base of camshaft lobe and valve tappet of both banks at "B". (Scheme 2) If clearance is not within specification, replace adjustment shim. See VALVE CLEARANCE SPECIFICATIONS table.
3. Rotate crankshaft clockwise about 240 degrees positioning No. 5 piston at TDC of compression stroke. Measure valve clearance between base of camshaft lobe and valve tappet of both banks at "C". (Scheme 2) If clearance is not within specification, replace adjustment shim. See VALVE CLEARANCE SPECIFICATIONS table.

VALVE CLEARANCE SPECIFICATIONS

Scheme 2

IGNITION TIMING

Note. Ignition timing is not adjustable. For inspecting ignition timing, warm engine to normal operating temperature. Turn off all accessories. Place transmission in Neutral (M/T) or Park (A/T). Wait for cooling fan to stop. Ensure idle speed is correct. See IDLE SPEED under IDLE SPEED & MIXTURE.

Scheme 3

1. Connect New Generation Star (NGS) scan tool to Data Link Connector (DLC) 2 located under left side of instrument panel, right of steering column. (Scheme 4) Connect a jumper wire between terminals TEN and GND at DLC 1 in engine compartment. (Scheme 5)
2. Ensure idle speed is correct. See IDLE SPEED & MIXTURE. Start engine and allow it to idle. Check timing. See «IGNITION TIMING SPECIFICATIONS»(ref-18649-S31651520252000123000000) table. (Scheme 6) Connect Inductive Timing Light (49-T018-002) lead to ignition timing checking harness (Black/White wire) located next to engine compartment relay box. (Scheme 3) NOTE: Standard inductive timing light may not work on ignition timing checking harness. Recommend using manufacturers Inductive Timing Light (49-T018-002) or equivalent
3. If ignition timing is not within specification, check for diagnostic trouble codes. See appropriate «TESTS W/CODES - 2.3L»(ref-18648) articles. Repair as necessary. If no codes are present, check camshaft position sensor and crankshaft position sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as necessary.

IGNITION TIMING SPECIFICATIONS

Scheme 4

Scheme 5

Scheme 6

IDLE SPEED & MIXTURE

Note. Idle mixture is not adjustable. If idle mixture is incorrect, see appropriate TESTS W/CODES - 2.3L article.

COLD (FAST) IDLE SPEED

Note. Fast idle speed is computer controlled. Adjustment is not necessary.

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). Wait for cooling fan to stop. DO NOT adjust idle using throttle adjusting screw. Throttle adjusting screw is preset and if adjusted, will adversely affect engine performance.

1. Connect New Generation Star (NGS) scan tool to data link connector 2 located under left side of instrument panel, right of steering column. (Scheme 4) Connect a jumper wire between terminals TEN and GND at data link connector in engine compartment. (Scheme 5)
2. Start engine and allow it to idle. Using scan tool, select PID/DATA MONITOR AND RECORD and monitor RPM. If idle speed is not within specification, rotate air adjusting screw on throttle body. (Scheme 7) See «IDLE SPEED SPECIFICATIONS»(ref-18649-S06936830672000123000000) table.

IDLE SPEED SPECIFICATIONS

Scheme 7

THROTTLE POSITION (TP) SENSOR

Note. DO NOT adjust throttle adjusting screw. Throttle adjusting screw is preset and if adjusted, will adversely affect engine performance.

CLOSED THROTTLE POSITION SWITCH

Closed throttle position switch is part of Throttle Position (TP) sensor, which is adjusted automatically when TP sensor is adjusted. See THROTTLE POSITION (TP) SENSOR.