I have a 97 f150 has 4.2. When I stop at a stop light sometimes it will start shaking a little and lose oil pressure and die. Unless I give it a little gas then it will stay running. This happens after I drive for a little bit. I run 10w 40 in it. The motor was locked up for a couple years and had coolant and oil sitting in there. I've ran sea foam through the motor. And sometimes it helps if I put Lucas in it. Any suggestions.