Engine - Hard Cold Start/Idles Rough/Stall or Near Stall
Article No.93-3-15
February 2, 1993
^ HARD COLD START - 4.0L - WHEN TEMPERATURE IS 30-70 DEGREES F (-1 TO 21 DEGREES C)
^ IDLE - ROUGH - 4.0L - WHEN TEMPERATURE IS 30-70 DEGREES F (-1 TO 21 DEGREES C)
^ STALL OR NEAR STALL - 4.0L - ON INITIAL STARTUP WHEN TEMPERATURE IS 30-70 DEGREES F (-1 TO 21 DEGREES C)
LIGHT TRUCK: 1991-92 EXPLORER
CALIBRATION:
0-58A-R00, 0-58P-R00, 1-58A-R10, 1-58P-R10, 2-58A-R00, 2-58P-R00, 0-58B-R00, 0-58R-R00, 1-58B-R10, 1-58R-R10, 2-58B-R00, 2-58R-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:
Long cold start times and rough idle with stall or near stall on initial startup may be experienced because of the sensitivity to low volatility fuels used in some southern states from May To September.
ACTION:
When the temperature is 30-70~ F (-1 to 20~C), use the following procedure to determine if it is necessary to install a new EEC IV processor with a revised strategy is required.
Determine if either cold start condition listed below is present.
1. The engine has a cold start time greater than 4 seconds and can be made to start by cycling the ignition key OFF and ON before the second start attempt.
2. The engine starts in a reasonable time, but idles rough and recovers, or stalls after start-up.
If either condition is present, use the following diagnostic procedure to determine if a new EEC IV processor with a revised operating strategy is required.
DIAGNOSTIC PROCEDURE
1. Confirm that the Electric Fuel Delivery System meets fuel pressure and leak-down time specifications by performing diagnostic procedures EFD2 and EFD3 of the 1992 Powertrain Control/Emissions Diagnosis Manual. Service as required.
2. If no service is required and the concern still exists, go to Step 4. Otherwise go to Step 3.
3. If service is performed following Step 1, recheck the start time. If the start time still exceeds 2 seconds, or if the start time is less than 2 seconds, but it is still necessary to cycle the key OFF and ON, then go to Step 4.
4. Install a new EEC IV processor. Refer to the EEC IV Processor Reference Chart in this article for correct parts usage. If the concern still exists, go to Step 5.
5. Perform the diagnosis procedure in the 1992 Powertrain Control/Emissions Diagnosis Service Manual. Service as required.
Obtain an Authorized Modifications Decal and list the date, dealer number, and summary of alterations 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 CLASS
F2PZ-12A650-YA EEC IV Processor B
F2PZ-12A650-ZA EEC IV Processor E
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS:
Eligible Under Bumper To Bumper For 1992 Models, Basic For 1991 Models
OPERATION DESCRIPTION TIME
930315A Verify Fuel Pressure And 0.3 Hr.
Leak Down Test
930315B Replace EEC IV Processor 0.3 Hr.
DEALER CODING
BASIC PART NO. CONDITION CODE
12A650 08
OASIS CODES:
602300, 607000, 607400, 608000, 608400, 618400