B250 3/4 Ton Van V8-360 5.9L VIN 1 4-bbl (1987)
Technical Service Bulletin # 184586
Date: 860901
Fuel system - Engine Vapor Lock
Models
1987 Van & Wagon Models Equipped With 5.2L or 5.9L Engine
Subject
Vapor Lock
Index
DRIVEABILITY
Date
September 22,1986
No.
18-45-86
P3392
Symptom/Condition, Diagnosis & Parts Information
SYMPTOM/CONDITION
Engine performance is gradually reduced in high ambient temperature or high altitude driving due to a drop in fuel pressure, which starves engine for
fuel (goes lean). Engine may not start until fuel system components cool off.
DIAGNOSIS
The following are characteristics of vapor lock and should be observed on a fully warmed up engine. (Vapor lock does not affect cold engine
driveability.)
^
Occurs after hot soak, prolonged idle, or highway speeds at any throttle opening.
^
Sag due to lean mixture.
^
No black smoke at tailpipe.
^
Fuel pressure drops to 0.
^
Carburetor air horn dry.
^
No accelerator pump discharge.
^
May not start until engine cools.
^
Engine may not sustain heavy loads.
PARTS REQUIRED
ORDER ONE OF THE FOLLOWING TWO PART NUMBERS:
Vapor Lock Package With 22 Gallon Fuel Tank
PN 4419405
Vapor Lock Package With 35 Gallon Fuel Tank
PN 4419406
Refer to parts list for contents of each package. Discard the instrument panel overlay harness, PN 4362559, which comes with the kit.
Must be ordered separately:
1
Instrument Panel Wiring Harness
PN 4362699
1
Authorized Modification Label
PN 4275086
NOTE:
IT IS IMPORTANT THAT THE SPECIFIED FUEL TANK SIZE APPLICATION PACKAGE BE SELECTED. THE USE OF
AN IMPROPER PART NUMBER PACKAGE MAY CAUSE THE VEHICLE TO RUN OUT OF FUEL WELL BEFORE THE
GAUGE READS EMPTY.
Repair Procedure
This procedure involves the installation of an electric fuel pump, control module, and fuel reservoir filter.
