the truck was low on gas and after making a pit stop (where I turned off the truck) it started up by quickly shut off. Now it turns over but wont start. I have put 5 gals of gas in it and after checking the fuse and fuel pump reset switch, I just replaced the fuel relay. It sound "more" like it wants to catch, but still doesn't start. Someone suggested spraying starting fluid in the valve cover, where is that? and what else might this be? I CAN her the fuel pump engage when I turn the ignition so I don't think its that.