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

1 Vapor Lock Package PN 4397613

1981-1984 models equipped with Carter Thermoquad 4BBL carburetor must order the following package in addition to the vapor lock package:

1 Fuel Pressure Regulator Package PN 4397656

Refer to parts list for contents of each package.
Must be ordered separately:

1 Authorized Modification Label PN 4275086