Engine - Idle Speed Fluctuation When Cold

Classification:
EC96-002

Reference:
ITB96-013

Date:
February 7, 1996

1994-96 G20 ENGINE IDLE SPEED FLUCTUATION AT FIRST STOP AFTER COLD SOAK

APPLIED VEHICLE:
1994-96 G20 (P10) with automatic transmission

APPLIED VIN:
Vehicles built before JNKCP01D*TT533001

SERVICE INFORMATION

This bulletin is to assist with servicing a 1994-96 G20 if it exhibits the following Symptoms: After sitting for a prolonged period of time in cold ambient temperatures (below 40°F) it has an unstable idle or the engine stalls during deceleration. This occurs intermittently within the first minute after the engine is started. Once the engine is warm, the incident goes away.

A countermeasure ECM has been developed which resolves this incident.

SERVICE PROCEDURE

1. Use of engine oil with a higher viscosity than 5W-30 may cause this incident. See Infiniti Technical Bulletin ITB91-039 (G191-005) for more information.

2. Verify that there are no other driveability incidents. Using CONSULT, make sure there are no diagnostic trouble codes (DTCs) stored in the ECM.





3. It is possible that a poor connection at the MAFS might give similar symptoms (see Figure 1).

A. To check the connection, wiggle the harness connection at the mass air flow sensor (MAFS) while monitoring "A/F ALPHA" (at 2000 rpm and engine at operating temperature) with CONSULT. "A/F ALPHA" should be in the 90-110% range and should not change while wiggling the connector.

B. If you suspect the connection to be unsatisfactory, refer to service bulletin ITB95-020 (EF & EC 95-01) dated April 5, 1995 to diagnose the CONSULT "A/F ALPHA" test.

4. If all preliminary checks are "OK", install the countermeasure ECM.

PARTS INFORMATION

DESCRIPTION PART # /PFP QUANTITY
ECM 2371M-0J220RE 1

CLAIMS INFORMATION





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