So I've thrown multiple hours and enough money at this truck already received it from my dad who had it 15 years no issues at all been driving it since summer ran totally fine untill it just recently got cold below freezing it will start when we put a heater under the engine and let it warm up or if the temperature reaches a certain degree during the day I've changed fuel pump fuel filter fuel regulator spark plugs ignition capacitor checked fuses and changed relays weird part is that starting fluid has worked a couple times and then there's been a few times where it will not work does anyone have any idea why it would only start up when the temperature is above the freezing mark definitely not fuel freeze up between new pump new filter and I've added heet to be sure it's not freezing please help