I helped my roommate put a holley blue on his 01 2500 2wd 5spd yesterday because his factory lift pump was was only putting out about 6-7psi going down the highway at 70mph and could easily be pulled below 5psi. His truck is stock other than a straight pipe. We mounted the pump to the frame just in front of the tank and used the factory lift pump harness to trigger a relay and the blue is run off of the relay. Our wiring connections are all solid and at idle we are seeing around 18-20 psi which is great. The problem is that as soon as you touch the throttle the pressure drops rapidly according to rpms. When you drive the truck as soon as you get to about 40mph you cant keep the pressure above 5 psi. This is accelerating very slowly. The fuel filter is new, just a couple hundred miles on it and i know we couldn't have gotten enough contamination in the lines to clog it. I know there are a lot of people running these holley pumps and seeing solid pressures so I don't understand why we are seeing so much better pressures at idle but other than that the pressures are so much worse. Using a mechanical isspro gauge without an isolator to monitor pressure so it doubtful that we are seeing bad readings. Any help is appreciated because I am stumped.

Blake

 

Ditch the stock pump completely. I always has problems with the stock one affecting my pressure. I ran a hooley blue and holley red for a year with more luck than the holle blue and stock one.

 

I agree. Get rid of the stocker. It's probably restricting flow.