Engine - Rough Idle/Stall After Cold Start

Article No.
95-7-14

04/10/95

^ IDLE - ROUGH - AFTER COLD START DURING FIRST MINUTE OF OPERATION - AT AMBIENT TEMPERATURES OF 50-70 DEGREES F (10-21 DEGREES C) - VEHICLES WITH 3.0L ENGINE AND AUTOMATIC TRANSMISSION - 49S CALIBRATION FOR 1993, 49S/CAL CALIBRATION FOR 1994

^ STALL - AFTER COLD START DURING FIRST MINUTE OF OPERATION - AT AMBIENT TEMPERATURES OF 50-70 DEGREES F (10-21 DEGREES C) - VEHICLES WITH 3.0L ENGINE AND AUTOMATIC TRANSMISSION - 49S CALIBRATION FOR 1993, 49S/CAL CALIBRATION FOR 1994

LIGHT TRUCK:
1993-94 RANGER

CALIBRATION:
3-56F-R10, 3-56H-R10, 4-56R-R00,
4-56S-R00, 4-56F-R10, 4-56H-R10,
4-56R-R11, 4-56S-R11

WARNING:
THIS MODIFICATION IS AUTHORIZED ONLY FOR THE LISTED ENGINE. PERFORMING THIS MODIFICATION ON OTHER ENGINE CALIBRATIONS IS UNAUTHORIZED AND COULD CREATE LIABILITY UNDER APPLICABLE FEDERAL OR LOCAL LAWS.

ISSUE:
A rough idle and/or stall during the first minute of operation after a cold start in ambient temperatures of 5O-70°F (10-21°C), may occur on some vehicles. This may be due to poor (low volatility) fuel quality.

ACTION:
Use the following Service Procedure to determine if a new EEC-IV Powertrain Control Module (PCM), with a revised richer cold starting fuel strategy, is required.

SERVICE PROCEDURE

NOTE:
THE FOLLOWING PROCEDURE WILL REQUIRE VEHICLE TO BE RETAINED OVERNIGHT.

1. Perform the diagnostic procedure in the 1993-94 Powertrain Control I Emissions Diagnosis (PC/ED) Service Manual. Service as required.





2. If no service actions are identified, or the concern still exists after performing service actions, install a new EEC-IV PCM. Refer to the Application Chart.





Obtain an Authorized Modifications Decal and list the date, dealer number, and summary of modifications performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modifications Decal. Clean the area, install the decal, and cover it with a clear plastic decal shield.

PART NUMBER PART NAME

F4PZ-12A650-NA Powertrain Control Module (PCM)
F4PZ-12A65O-RA Powertrain Control Module (PCM)
F4Pz-12A650-A Powertrain Control Module (PCM)
F4PZ-12A650-SA Powertrain Control Module (PCM)

WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage

OPERATION DESCRIPTION TIME

95O714A Perform EEC-IV Quick Test, 0.8 Hr.
Replace PCM And Perform
Final Quick Test

DEALER CODING
BASIC PART NO. CONDITION CODE
RECAL 82

OASIS CODES: 607400, 608400