last year I had a similar problem with our l2, it would run for about 2 Hrs., then we'd get a fuel restriction warning. I'd clean our the sediment bowl and find, a clear snotlike substance on the screen and hairlike streaks in the bowl itself. Took the fuel tank off and washed it out, but the same problem continued. Changed fuel filter nothing helped. ** learned this year from a local automotive store, that they believed we had bacteria in the diesel fuel, they sold me some stuff called Ag Trac conditioner** Problem solved. I was skeptical at first but worked this Fall without fuel problem.