My truck had been sitting in a field for 6 yrs with hardly any gas in it for 6 yrs..The inside of the tank had a nice coating of red surface rust..I went through about 6 fuel filters before it got better..I bought the clear ones so you can see how clogged they are getting..Always keep your tools and an extra filter..Didn't want to pull the tank, and it worked..Good Luck, Steve