Engine - Poor Driveability, Fuel Gauge Fluctuation
Bulletin No.: T-93-123File in Group: 6
Number: 49
Corp.Ref.No.: 316306
Date: Aug. 1993
SUBJECT:
INTERMITTENT HESITATION, FUEL GAUGE FLUCTUATION, POP NOISE ON COLD START
MODELS AFFECTED:
1989-1993 FWD DE VILLES, FLEETWOODS, AND SIXTY SPECIALS
Some 1989-1993 FWD DeVilles, Fleetwoods, and Sixty Specials may experience fuel tank plastic reservoir breakage that may cause the following symptoms:
^ Intermittent hesitation; rough running; lack of power.
^ Intermittent inaccurate or fluctuating fuel gauge.
^ Pop noise on cold starts after an overnight soak.
The fuel tank plastic reservoir breakage is caused by a combination of reservoir material embrittlement during exposure to various fuel types and expansion and contraction of the fuel tank due to pressure/vacuum cycling. Pieces of the broken plastic reservoir may scrape the fuel tank lining material off the floor of the tank which can then restrict the fuel tank strainer and cause the driveability symptoms listed above. The broken reservoir pieces may also restrict movement of the float arm and cause fuel gauge inaccuracies or fluctuation.
Service bulletin T-93-35 addresses the pop noise condition and describes a repair for the pressure/vacuum cycling with a revised tank pressure control valve (TPCV). If the pressure/vacuum cycling has gone on long enough, it may have caused damage to the reservoir and will require fuel tank replacement. All service fuel tanks are built with a reservoir made of a revised material that should not become brittle and break.
To repair this condition remove the fuel tank and check the plastic reservoir. If the reservoir is broken, replace the tank pressure control valve (P/N 17089068) and fuel tank (P/N 25608430). If the reservoir is not broken and the only condition reported by the customer is the pop noise on a cold start, replace only the TPCV per Service bulletin T-93-35.
Parts are currently available from GMSPO.