Engine - Detonation/Hard Start/Rough Idle/Stall

91ford17

Article No.
91-9-5

05/01/91


^ DETONATION - 3.8L (N/A) - DURING WIDE OPEN THROTTLE AT NORMAL ENGINE OPERATING TEMPERATURE

^ HARD START - 3.8L (N/A) - LONG CRANK TIME DURING INITIAL COLD START

^ IDLE - ROUGH - 3.8L (N/A) - DURING FIRST 30 SECONDS OF COLD START

^ STALL - 3.8L (N/A) - DURING FIRST 30 SECONDS OF COLD START


FORD: 1989-90 THUNDERBIRD

LINCOLN-MERCURY: 1989-90 COUGAR


ISSUE: A hard/slow start may occur at the initial cold start followed by a rough idle during the first 30 seconds. Spark knock may also occur during wide open throttle operation at normal engine operating temperature. These conditions occur because of the operating strategy of the EEC IV processor.

ACTION: Use the following procedure to determine if a new EEC IV processor is required.


1. Perform the diagnostic procedures in the 1989/90 Engine/Emission Diagnosis Shop Manual. Service as required.

2. If the conditions still exist, install a new EEC IV processor with a revised operating strategy.

3. Refer to the following Parts Block for correct parts usage.





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

F0PZ-12A650-GA EEC IV Processor (49 State) B
F0PZ-12A650-FA EEC IV Processor (California) W


OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Eligible Under Basic Warranty Coverage

OPERATION DESCRIPTION TIME
910905A Perform Engine/Emissions 0.5 Hr.
Diagnosis.
910905B Replace EEC IV Processor 0.7 Hr.

DEALER CODING
BASIC PART NO. CONDITION CODE
DRIVE J7
OASIS CODES: 602300, 607000, 608400, 615000