Ok guys, Im still at a loss, and id love to gather anyones ideas. PPE dual pump setup a few years old, bought used. When i had stock injectors the pump just started to lightly knock when you first hit the key over then it went away after a few seconds. Now i have Exergy 100s and the pump constantly knocks.. NOT fuel injector rattle as you can hear that plain as day when you unhook the regulator. I Installed a new pump on it last night and same thing . Also got a low rail pressure code on my tune 4 just test driving it earlier (I think thats odd) Valley cp3 was fine when i did the duals and theyre only about 2 months old on my truck. Raptor 150 feeding them. Unhook the liftpump and the knock goes away and truck tries to surge and die. So....Who can tell me whats going on?? 114k miles LMM 68stg2r 100s,built trans all supporting mods, dual pumps. https://www.youtube.com/watch?v=CFs3ZHi-W7w
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