Engine - Surging/Bucking At High Speeds
87ford15
Article No. ^ SURGING - "TRAILER HITCHING/ENGINE
87-18-22 MISS" - 5.0L EFI WITH AUTOMATIC
TRANSMISSION
^ BUCKING -"TRAILER HITCHING/ENGINE
MISS" - 5.0L EFI WITH AUTOMATIC TRANSMISSION
LIGHT TRUCK: 1987 E SERIES, F SERIES, BRONCO
CALIBRATIONS: 7-54E-R05, 7-54J-R05, 7-54R-R05, 7-54S-R05, 7-54V-R10, 7-54W-R05, 7-54Z-R05, 7-54K-R10, 7-54T-R10
WARNING: This modification is authorized only for the listed engines. Performing this modification on other engine calibrations is unauthorized and could create liability under applicable federal or local laws.
ISSUE: Surging and/or bucking (sometimes refered to as "trailer hitching") at speeds greater than 55 MPH (88 km/h) after backing off the throttle and then tipping back into the throttle may be caused by an excessively rich "fuel pulse" output during acceleration. This condition is caused by the EEC IV processor and should not be improperly diagnosed as a harsh transmission shift.
ACTION: To correct this, install a new EEC IV processor using the following service procedure. Refer to EEC IV processor application chart on page 61 of this TSB for service replacement part numbers.
1. Perform EEC IV Quick-Test and correct service code(s) as necessary.
2. If concern still exists, proceed to Step 3.
3. Install a new EEC IV processor assembly.
NOTE: Send original processor assembly to Warranty Parts Return Center.
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
E7TZ-12A650-ATB EEC IV Processor B
E7TZ-12A650-AUB EEC IV Processor B
E7TZ-12A650-AXB EEC IV Processor B
E7TZ-12A650-AYB EEC IV Processor B
E7TZ-12A650-BCB EEC IV Processor B
E7TZ-12A650-BBB EEC IV Processor B
E7TZ-12A650-AVC EEC IV Processor B
E7TZ-12A650-AZC EEC IV Processor B
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Eligible Under Basic Warranty Coverage
OPERATION: SP871822A
TIME: 1.3 Hrs. DLR. CODING: Basic Part No. DRIVE - Code: M4
EEC IV PROCESSOR APPLICATION CHART
(Engineering Part Number) (Service Part Number)
Calibration Existing EEC IV Processor EEC IV Processor
7-54E-R05 E7TF-12A650-ATA E7TZ-12A650-ATB
7-54J-R05 E7TF-12A650-AUA E7TZ-12A650-AUB
7-54R-R05 E7TF-12A650-AXA E7TZ-12A650-AXB
7-54S-R05 E7TF-12A650-AYA E7TZ-12A650-AYB
7-54V-R10 E7TF-12A650-BCA E7TZ-12A650-BCB
7-54W-R05 E7TF-12A650-BBA E7TZ-12A650-BBB
7-54Z-R05 E7TF-12A650-BCA E7TZ-12A650-BCB
7-54K-R10 E7TF-12A650-ATA E7TZ-12A650-AVC
7-54T-R10 E7TF-12A650-AXA E7TZ-12A650-AZC