Engine - Bucks/Jerks During Deceleration

88ford26

BUCKS/JERKS - 3.8L - DURING DECELERATION

Article No. 88-23-9

FORD: 1984-87 THUNDERBIRD

LINCOLN-MERCURY: 1984-87 COUGAR

ISSUE: A bucking or jerking condition during deceleration for the first few miles of vehicle operation after a cold start may be caused by a rich air/fuel mixture. The rich air/fuel mixture may be present during deceleration with a closed throttle.

ACTION: Install a new MAP sensor that helps produce a lean air/fuel mixture. Refer to the following procedure for service details.

NOTE: THIS PROCEDURE MAY ONLY PROVIDE MARGINAL IMPROVEMENTS TO SOME VEHICLES.

1. Perform EEC-IV self test and correct any service codes as required.

2. Check the fuel system pressure. Refer to the appropriate Car Shop Manual, Volume D, Section 24-03-3 for service details.

3. If the fuel pressure is greater than 40 psi reduce it to 35 psi by using the following procedure:

a. Remove the protective plug from the top of the fuel pressure regulator.

b. Insert a hex head wrench into the adjusting screw of the fuel pressure regulator and set the fuel pressure to 35 psi.

c. Reinstall the protective plug on th efuel pressure regulator.

NOTE: DO NOT REDUCE THE FUEL SYSTEM PRESSURE FOR ANY OTHER TYPE OF CONCERN OTHER THAN A BUCKING AND JERKING CONDITION.

4. Install a new MAP sensor, E5SZ-9F479-A.

NOTE: DO NOT INSTALL A MAP SENSOR THAT IS MARKED WITH A "YELLOW" DOT.




AUTHORIZED MODIFICATION DECAL 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

E5SZ-9F479-A MAP Sensor AM

OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Eligible Under Basic Warranty Coverage
OPERATION: 882309A
TIME: 1.3 Hrs.
DLR. CODING: Basic Part No. DRIVE
Condition Code: K5
OASIS CODES: 630200, 632000