Here's a thought, I'm sure it's a no brainer, but have you checked the fuel lines for leaks through the entire length, say near the tank or at the fuel rail? Possibly at the Fuel Filter? I've also seen clogged fuel filters also than can create a weird suction effect after the engine is shut off continuing fuel flow after engine shut off, but usually that would result in a flooded engine. How about gas tank rust? Any possible rust holes? Anyway, just a thought. Occam's Razor is often right. "one should not make more assumptions than the minimum needed" If the engine is operating properly, perhaps it is somewhere in the fuel delivery or storage that is causing your fuel loss.

Just my 2 cents which I'm sure or worth less than that. <img src="/forums/images/graemlins/ignore.gif" alt="" />

You got a locking gas cap on that rig ? Any chance the "hose" is killing yer mileage ?

Had a friend years ago who used to brag about his gas mileage... until me and his brother decided to play a trick on him. We siphoned a few gallons a week... He kept taking the thing back to the dealer, no problem found (naturally!)... So, then we decided to go the other way, we were putting several gallons a week back in. He was up over 45 mpg at one point. (gas was cheap then, and practical jokes are worth it). Then he caught us in the act. He wasn't amused.