Idle Speed & Mixture

NOTE: Ignition timing and valve clearances must be correct and engine must be at normal operating temperature prior to adjusting idle speed and mixture.

Disconnect canister purge hose at check valve near intake manifold. Plug hose, then start engine and warm up for at least 5 minutes. Adjust idle speed with transmission in neutral.

Fig 1: Idle Mixture Teat Connections
Courtesy of SUBARU OF AMERICA, INC.

NOTE: idle mixture should not need adjustment unless carburetor has been removed and disassembled. Roll pin must be removed from in front of idle mixture screw before adjustments can be made.
Connect a dwell meter to Green/White wire in Pink connector near right front shock tower. Set meter on 4-cylinder scale and observe needle movement with engine idling. See Fig 1 .
Dwell meter needle should move up and down within 30-40° range. If not moving, run engine at 2000-3000 RPM for at least 2 minutes, then recheck.

If dwell meter needle movement is not within specified range, adjust idle mixture screw until needle movement is between 27-36°. Recheck idle speed, then remove test equipment, reconnect purge hose and install roll pin.

IDLE SPEED SPECIFICATIONS

Application

Man. Trans.

⁽¹⁾ Auto. Trans.

All Models

600-800

700-900

⁽¹⁾	In Neutral.