I've read much about folks having problems with their lift pumps and some dissatisfaction with FASS
I had problems and installed a FASS
, but the damage was already done to the VP44. Installed a new IP, but my fuel pressure would still go down under WOT. DieselPerformanceParts.com
has, in their instructions on how to do a diagnosis for lift pump problems.
It's the 5 gal bucket test. Basically you take the suction and return line off of the tank. Put them both in a bucket that has diesel. Start the motor and check pressure and flow. My problem was the in-tank filter, at the end of the draw straw, was clogged, thereby reducing flow under demand. The instructions should come with the installation instructions and might be available on their web site. If you are having other problems with the FASS
, call Dan @ 1-866-769-3747. He was very easy to work with.
Hope this helps, it would have saved me a couple thousand, had I known.