Fuel - Idle Speed Fluctuations

Classification: EF&EC94-014
Section: Emission Control
Reference: TECHNICAL BULLETIN NTB94-085
Models: 1989-93 Maxima
Date: August 24, 1994

MAXIMA IDLE FLUCTUATION

APPLIED MODELS:
1989-93 Maxima (J30)

SERVICE INFORMATION

This bulletin is intended to assist in diagnosis and repair if a customer complains of the following idle related symptoms:

* Idle speed drops below 750 rpm.

* The ECCS attempts to recover to 750 rpm and "overshoots" to about 1000 rpm.

* After "overshooting", the idle speed will slowly drop to 750 rpm.

* Idle fluctuates (in Neutral or Park) or the engine speed drops below 750 rpm (in Drive) when coming to a stop.

REPAIR INFORMATION

This incident may be caused by "turbulent" air flow which creates an inaccurate reading from the air flow meter and usually occurs after the vehicle reaches operating temperature. A related cause for this "turbulent" air flow may be an uneven application of viscous oil on the air filter (by the filter manufacturer) which may be related to the use of a non-genuine Nissan air filter element. Installing a Genuine Nissan air filter may improve or resolve the incident.

This incident can be identified by lifting the air filter top away from the air filter box assembly and checking to see if the idle fluctuation no longer occurs. A countermeasure Air Cleaner Box Assembly (incorporating a different shaped air funnel) is available if installation of a genuine air filter doesn't resolve the incident:

Part Number Description

16500-85E01 Air cleaner assy.