Engine Controls - Difficult Start/Idle & Timing

Classification:
EC96-007

Reference:
NTB96-061

Date:
June 5, 1996

1993-1995 ALTIMA ENGINE CRANKS BUT WILL NOT START/IS HARD TO START IN HIGH ELEVATION/LOW AMBIENT TEMPERATURES

APPLIED VEHICLE:
1993-1995 Altima (U13)

SERVICE INFORMATION

If it is difficult to start the engine (the starter operates, but the engine does not start) in a 1993-1995 Altima, the cause may be low base idle speed adjustment or an over-rich air/fuel mixture during cranking. Perform the following procedure to diagnose and repair the vehicle.

SERVICE PROCEDURE

1. Check the base idle speed and ignition timing. Use the "IDLE SPEED/IGNITION TIMING/IDLE MIXTURE RATIO ADJUSTMENT" procedure in the appropriate service manual. If the base idle speed (IACV-AAC valve held fixed) is out of specification (low), adjust to specification. Then, using the customer's description of conditions when the incident occurs, attempt to duplicate the complaint.

^ If the incident is resolved after performing these adjustments, return the vehicle to the customer.

^ If the incident is not resolved, proceed to step 2.





Base idle speed and ignition timing specifications:

2. If the base idle speed is wi1hin specifications, perform the appropriate next step, depending on the model year of the vehicle:





1995 Model Year

A countermeasure ECM has been developed which provides a leaner air/fuel mixture ratio during engine starting. This countermeasure has already been applied to all 1996 Altima production. Install the appropriate countermeasure ECM from the table.





1993-1994 Model Year

A countermeasure engine coolant temperature sensor, which provides a leaner air/fuel mixture ratio during engine start-up has been developed for this incident. Use the part number listed below.





CLAIMS INFORMATION

Submit a Primary Failed Part claim using the following coding: For 1995 Model Year Altimas





For 1993-1994 Model Year Altimas