Put a lift pump on the lml did some back road testing it def did help the draining rail but the more I look in to this I am not conviced that its is the cp4 that is weak... Does the lml have a relief? Is it mech or elec...? On my particular truck it loses rail in weird situtuions...when the truck is decel like in tow haul with 0% throttle then you stab the throttle instantly it drops rail from a dead stop full throttle it doesnt drain.... Well tommorow I am going to hook her to the sled that will give me some more Insight