1990 Nissan Stanza Timing

Start engine and warm to normal operating temperature (coolant gauge needle in middle). Open engine compartment hood and run engine at 2000 RPM for 2 minutes. Perform self-diagnostic procedure. See TESTS W/CODES article. Check for smooth engine operation.
Increase engine speed to 2000 RPM, 2 or 3 times, then allow engine to return to idle. Check idle speed and ignition timing. See 4-CYLINDER IGNITION TIMING table. See Fig. 1. If ignition timing is correct, check idle mixture.
If ignition timing is incorrect, disconnect throttle position sensor harness connector. If engine speed is more than 800 RPM, reduce idle speed with idle speed adjusting screw. See Fig. 2 or Fig. 3.
Recheck ignition timing. If timing is incorrect, loosen hold-down bolt and turn distributor. With ignition timing correctly set, reconnect throttle position sensor. Check idle speed, oxygen sensor and idle mixture.