What is the fast idle speed specification at the 2nd cam step?

1,800 - 2,600 rpm for manual transmission (M/T) and 1,900 - 2,700 rpm for automatic transmission (A/T).

What is clearance "A" for fast idle adjustment?

0.63±0.07 mm (0.0248±0.0028 in) for M/T and 0.80±0.07 mm (0.0315±0.0028 in) for A/T, measured between the primary throttle valve and inner carburetor wall, adjusted with the fast idle adjusting screw.

How do I set the fast idle arm on the 2nd step of the fast idle cam?

Warm up the engine sufficiently, then move the throttle lever counterclockwise fully; in this condition the fast idle arm is set at the 2nd step.

What does a zero voltmeter reading across GY/R and B indicate for the choke heater circuit?

Check for a disconnected connector, an open circuit, or a faulty automatic choke relay. A 12-volt reading means the heater circuit is functioning properly.

What type of automatic choke relay is used and where is it located?

A 1M-1B type standardized relay is used; for its location, refer to Location of Electrical Unit in section EL.

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Nissan Micra Carburetor Fast Idle & Auto-Choke Relay Check - EF & EC-16

Carburetor automatic choke heater circuit and fast idle inspection, Nissan EF & EC manual

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Carburetor inspection page: automatic choke (PTC) heater relay circuit voltage check (12V) and fast-idle cam adjustment with fast-idle speed specs and connector pinout.

AI caption June 2005 · Photo 116 of 412

This is page EF & EC-16 from a Nissan service manual's Carburetor section, covering continued Inspection and Adjustment procedures. The left column completes the automatic choke heater circuit check: verifying continuity of the P.T.C. heater circuit, checking for 12 volts across the GY/R and B wires with the engine idling, and diagnosing a zero-volt reading as a disconnected connector, open circuit, or faulty automatic choke relay. An illustration shows the function check connector near the fuse block, and a wiring schematic identifies a black 12-pin connector with GY/R and B wires and legend items: ignition relay, auto-choke relay, auto-choke heater, and alternator "L" terminal (figure SEF332B). It notes a 1M-1B type standardized relay is used. The right column details the fast idle procedure: warm the engine, set the fast idle arm on the 2nd step of the fast idle cam by moving the throttle lever counterclockwise fully, and read engine speed. Fast idle speed at the 2nd cam step should be 1,800–2,600 rpm (M/T) or 1,900–2,700 rpm (A/T). If out of spec, remove the carburetor and adjust clearance "A" between the primary throttle valve and inner carburetor wall: 0.63±0.07 mm (M/T) or 0.80±0.07 mm (A/T).

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Frequently asked questions

What is the fast idle speed specification at the 2nd cam step?: 1,800 - 2,600 rpm for manual transmission (M/T) and 1,900 - 2,700 rpm for automatic transmission (A/T).
What is clearance "A" for fast idle adjustment?: 0.63±0.07 mm (0.0248±0.0028 in) for M/T and 0.80±0.07 mm (0.0315±0.0028 in) for A/T, measured between the primary throttle valve and inner carburetor wall, adjusted with the fast idle adjusting screw.
How do I set the fast idle arm on the 2nd step of the fast idle cam?: Warm up the engine sufficiently, then move the throttle lever counterclockwise fully; in this condition the fast idle arm is set at the 2nd step.
What does a zero voltmeter reading across GY/R and B indicate for the choke heater circuit?: Check for a disconnected connector, an open circuit, or a faulty automatic choke relay. A 12-volt reading means the heater circuit is functioning properly.
What type of automatic choke relay is used and where is it located?: A 1M-1B type standardized relay is used; for its location, refer to Location of Electrical Unit in section EL.