I installed a set of KD lift pumps a couple months ago. Immediately after the install it would buck hard at about 60 mph only with higher HP tunes where as everything, tunes, etc was working perfectly before the install. It took a couple weeks to figure it out, but I bled the fuel system by pumping compressed air from my compressor into the fuel tank filler (filler neck sealed with tape around the air hose) and bled the system via the black plastic bleed screw on the fuel filter housing, and the pressure test port on the hard line under the plastic screw on cap. The problem got much better. I then bled the system more and the problem went completely away. Then, at a later date, I added the KD mega fuel filter between the two KD lift pumps. This obviously got air back in the system and the problem came back identically. I then put the air compressor hose in the tank at 30psi and opened the bled screw on the side of the KD fuel filter between the twin lift pumps, and bled the system via the black plastic bleed screw on the fuel filter housing, and the pressure test port on the hard line under the plastic screw on cap. The problem, sever buck, is still the same. I did the above bleeding with the truck running and with out it running and with and without the KD lift pumps running. It can be bled with the tuck and pumps not running since the compressed air in the fuel tank will push fuel through the system. I've bled at least a gallon of fuel from all three ports with no luck. Any suggestions?
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