Engine - Stalling At Idle And Initial Start Up
Article No.95-20-7
10/11/95
STALL/NEAR STALL - ROLLING IDLE/STALL - AT
IDLE ON INITIAL START-UP - SFI/OHC - MANUAL
TRANSMISSIONS - 3.45 OR 3.73 AXLE - CALIFORNIA
CALIBRATION VEHICLES
LIGHT TRUCK:
1994 RANGER
This TSB article is being republished in its entirety to include the latest level parts.
CALIBRATION:
4-49T-R00
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:
Some vehicles may stall or near-stall on initial start-up after an extended soak time and engine at ambient temperature. This is due to fuel calibration requirements of the Powertrain Control Module (PCM), at certain ambient temperatures, not properly matched to fuel requirements during initial start-up. This causes a lean condition and the engine is not able to receive the required fuel for proper idle.
ACTION:
Refer to the following procedure for service details.
DIAGNOSIS AND REPAIR PROCEDURE
1. Diagnostic Trouble Code (DTC) Check
a. Perform normal diagnosis to be sure that no fault is present. Refer to the Powertrain Control Emissions Diagnosis (PC/ED) Car/Truck Service Manual (OBD I) for Malfunction Indicator Lamp (MIL) concerns.
b. If any DTC's are found, they must be repaired before proceeding.
c. If no DTC's are found and the condition still exists, continue with the "Diagnostic Routines" in Section 2A of the PC/ED Car/Truck Service Manual (OBD I) before continuing with the following diagnosis.
2. PCM Calibrations
a. Check if the vehicle has service replacement PCM, part number F4PZ-12A650-UA, installed.
b. If the vehicle does not have the service replacement PCM installed, refer to the following step.
3. PCM Replacement
a. Install the correct PCM. Refer to the 1994 Ranger Service Manual for procedure.
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-UA Powertrain Control Module (PCM)
OTHER APPLICABLE ARTICLES: NONE
SUPERSEDES: 94-24-12
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage
OPERATION DESCRIPTION TIME
952007A Perform Quick Test; 0.8 Hr.
Replace Powertrain Control
Module (PCM); Perform
Final Quick Test
DEALER CODING
CONDITION
BASIC PART NO. CODE
RECAL 08
OASIS CODES: 607400, 608400, 618400