i have a 2000 blazer and the fuel gauge will read anywhere between 3/4 and full most of the time and then out of nowhere for no reason it will plummet to empty.... but only for a few seconds and then it goes right back to where it was.... i set the trip meter to know if im getting low on fuel and even if i know im runnin low it still says 3/4 or full and then to empty.... is the prob in the fuel pump??

 

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98+ Fuel Gauge Diagnosis