What is the idle CO% specification in this procedure?

Idle "CO"% is 2.0±1.0 for M/T and 2.0±1.0 for A/T (measured in "D" position).

What are the idle speed specifications?

M/T: 750±50 rpm; A/T: 700±50 rpm in "D" position.

How is idle speed adjusted if it is out of spec?

By turning the throttle adjusting screw, then racing the engine (2,000–3,000 rpm) 2 or 3 times under no load and rechecking idle speed.

Why is a special screwdriver needed for idle adjustment?

A metal idle limiter cap has been adopted, so the idle adjusting screw must be adjusted with the idle adjusting screwdriver, tool KV10104500.

What must be reconnected once idle CO% is O.K.?

Turn off the engine, connect the air injection hose to the air pipe, and connect the throttle opener control valve hose to the throttle opener control valve, then restart the engine.

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Nissan Idle Speed & CO% Adjustment After Warm-up - Service Manual Page MA-17

Engine maintenance flowchart for idle adjustment after warm-up with gauge figures

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Service procedure flowchart for idle-speed and CO adjustment after engine warm-up with throttle-screw and gauge references.

AI caption April 2005 · Photo 37 of 412

This page, MA-17 from a factory service manual's Engine Maintenance section titled "After Engine Warm-up (Cont'd)", presents a flowchart procedure for checking and adjusting idle CO percentage and idle speed after engine warm-up. The procedure instructs the technician to race the engine (2,000–3,000 rpm) two or three times under no load, run at idle, and check idle "CO"% against a specification of 2.0±1.0 for both M/T and A/T (A/T in "D" position). If not good, idle CO is adjusted via the idle adjusting screw; if good, the technician reconnects the air injection hose and throttle opener control valve hose, restarts the engine, races it again, and checks idle speed against specifications of 750±50 rpm (M/T) and 700±50 rpm (A/T in "D" position), adjusting with the throttle adjusting screw as needed until the procedure ends. Illustrations identify the throttle adjusting screw and idle adjusting screw locations on the carburetor (figure SMA719A), a tachometer (SMA716A), and a special idle adjusting screwdriver, tool number KV10104500 (figure SMA356), which is required because a metal idle limiter cap has been adopted. The page contains no explicit year, model, or engine identification.

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Frequently asked questions

What is the idle CO% specification in this procedure?: Idle "CO"% is 2.0±1.0 for M/T and 2.0±1.0 for A/T (measured in "D" position).
What are the idle speed specifications?: M/T: 750±50 rpm; A/T: 700±50 rpm in "D" position.
How is idle speed adjusted if it is out of spec?: By turning the throttle adjusting screw, then racing the engine (2,000–3,000 rpm) 2 or 3 times under no load and rechecking idle speed.
Why is a special screwdriver needed for idle adjustment?: A metal idle limiter cap has been adopted, so the idle adjusting screw must be adjusted with the idle adjusting screwdriver, tool KV10104500.
What must be reconnected once idle CO% is O.K.?: Turn off the engine, connect the air injection hose to the air pipe, and connect the throttle opener control valve hose to the throttle opener control valve, then restart the engine.