I bought a fass 150 95gph titanium series in August 2015. Truck has been running perfect. Just went to start it up this morning and the motor on the top of the fass pump is sounding weird and if you put your hand on it whIle the truck is running it almost feels like it has a knock to it and it's very loud. When I bump the starter the pump sounds like it's cavitating and it makes no psi on my gauge. When the truck is running it makes about 15 at idle rather than the usual 18. I'm lost on where to even begin looking. I don't understand why it pushes air when the engine isn't running but pushes fuel when the engine is running. Any help would be greatly appreciated. Thanks.

 

Have you tried calling fass and see what they have to say?