Thunderbird V8-302 5.0L (1984)
Fuel Gauge: Customer Interest
Fuel Gauge - Erratic Readings
Article No. 84-7-8
FUEL GAUGE - READING ERRATIC
FORD 1984 THUNDERBIRD
LINCOLN-MERCURY 1984 COUGAR
Erratic fuel gauge reading may be caused by a pinched fuel system vent tube.
Vehicles built prior to January 15 may exhibit a condition of low fuel indication after the vehicle has been operated for a short period of time. The
electronic fuel gauge may display 1 to 3 bars lower than initially displayed, while the conventional fuel gauge indication may drop 1/8 of a tank. After
the ignition is turned off and the fuel tank pressure allowed to subside, the fuel level indication may recover to the correct reading.
The above condition could be caused by a pinched vent tube from the fuel tank to the carbon canister due to misrouting of the vent tube over the top of
the fuel tank. Refer to 1984 shop manual "D" Section 24-50, pages 6, 7, 8 for diagnosis of blocked or pinched evaporative emission lines or other
possible causes for pressure in the fuel tank. The possible increase in tank pressure caused by the pinched vent tube may result in slight fuel tank
expansion and subsequent inaccurate fuel level readings.
To service the pinched vent tube, the fuel tank must be dropped and the vent tube routed correctly between the tank and the vehicle body in the
depression provided on the fuel tank. The tank removal procedure described in Section 24-50 of the 1984 Thunderbird/Cougar service manual should be
consulted.
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: "INFORMATION ONLY"
