So the other day I drive my truck about 40 miles and as usual it goes perfectly. it sits for about half an hour, and I jump back in to go home. but i step on the peddle and no power. runs good just no power. so I'm going down the road and slowly seems to come back and runs OK all the way home. So I decide to change the fuel filter which i did. filled the filter with fuel. takes forever to start, but eventually does. Next day i head to my camp (90 miles) and runs good but power comes and goes. it doesn't surge, but power comes and goes. Same thing coming home. feels like a plugged fuel filter, but the one i took off looked clean and i put a new one on it. any way to tell if its the ip? or the lift pump?