also, for others who might come across this post looking for answers, i had a similar problem. and im surprised im the first to post this, but clean out that gas tank!, i looked down in mine and it looked like just a small amount of rust, but after sticking a rod down in the tank it went into what i thought was the bottom about 3/4 of an inch! nothing but decomposed rust and debris, sludge and all kinds of other good stuff. Cleaned it out, replaced the pump, filter, and threw and extra filter in front of the pump for safety measures. Havnt had an issue since.