The 87/88 motors won't stay energized. There are two safety functions in their module. One is timed, the other is resistance.
I would look at a trunk light or as Pat suggested, the fuel pump relay. Put your phone on video, stand it inside the trunk and close the lid.
Alternately lift and press on the lid, then check the video. You can unplug the harness for the oil pressure sender to see if that resolves the problem. Sending units sometimes stick and keep the relay energized. You should be able to hear the pump run. You may have to take a length of hose, lay down on the ground and place one end at the tank and the other to your ear if the pump is quiet.