Altima, Frontier, Sentra, 200SX & 240SX

Start engine and warm to normal operating temperature. Turn ignition off. Disconnect Throttle Position (TP) sensor harness connector.
Start engine. Increase engine speed to 2000 RPM, 2 or 3 times, then allow engine to return to idle. Engine should be operating smoothly at correct idle RPM. Check ignition timing. See 4-CYLINDER IGNITION TIMING table. See Fig 1 and Fig 2 .
If ignition timing is incorrect, loosen hold-down bolt and turn distributor to adjust ignition timing. Turn ignition off, connect throttle position sensor harness connector and tighten distributor hold-down bolt. Recheck ignition timing.

4-CYLINDER IGNITION TIMING ⁽¹⁾

Application

Man. Trans.

⁽²⁾ Auto. Trans.

Altima & 240SX

18-22 @ 600-700

Frontier

18-22 @ 700-800

Sentra & 200SX

1.6L

6-10 @ 575-675

6-10 @ 675-775

2.0L

13-17 @ 700-800

⁽¹⁾	Specifications in degrees BTDC @ RPM.

⁽²⁾	Automatic transmission/transaxle in Neutral.

Fig 1: Ignition Timing Marks (Altima, Frontier & 240SX)

Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 2: Ignition Timing Marks (Sentra & 200SX 1.6L Shown; 2.0L Is Similar)

Courtesy of NISSAN MOTOR CO., U.S.A.