2004 Ford Ranger

My 3.0 v6 ranger is misfireing. When you drive down the road under 60 mph(barely on the pedal)it will lose power. It doesnt shut off though. And the check engine light will start to blink. If you keep driving for about ten seconds it clears up for about 3-5 minutes. Then its back again. Now when your 60+mph(into the pedal)it doesnt hesitate. No misfire or blinking engine light. This makes me think there is something wrong in the fuel pump area. No fuel leaks anywhere.I did press the purge valve on my fuel rail and air came out along with fuel. There are no leaks anywhere how could this happen and could this be my problem?What would need to be replaced? This truck has no egr valve, I have replaced fuel filter, plugs, wires and coil. The fuel regulater is in the fuel tank. There is also a charcol canister located near the tank. Im not sure how it works or if its bad. Any and all help would be greatly appreciated. Thank you very much.