vp44 intermittent power loss

From : coachmike

Q: 99 dodge ram with 120000 miles on it. the lift pump and vp44 replaced under warranty at 65000 has been trouble free until recently. seems to be the same scenario others are experiencing with a little twist. it will run fine until it de-rates and loses power but can usually maintain 55-60 mph. if you let off the throttle momentarily and apply again it will usually pick back up. there is no set pattern it happens randomly. there are two codes present unfortunately i dont have them available with me but the ecm failed code comes on immediately after theyre cleared the fuel pump code part of it is p-16 but cant remember doesnt show until it actually loses power. however there are no problems yet when the ambient temp is under 80-85 degrees which leads me to wonder several things ecm breaking down electronically due to heat vp-44 - same scenario fuel temp too high causing low viscosity / poor lubrication i should add that i replaced the lift pump but have no way of checking pressures. it worked fine for an hour driving to the beach but then starting it again. at times there is little to no throttle response at cold startup when ambient temp over 95 as in at the shore. i am capable of replacing the pump or ecm myself but dont want to throw parts at it without more diagnosis. .