Ford E-250 , momentarily loosing oil pressure.
 

Good day idk if this is where I'm supposed to put this , but I'm haveing issues with my oil pressure. When I accelerate for a stop or going 20mph or less around a turn when I start accelerating my oil pressure gage bottoms out then after a second or 2 it will pop back up where it normally is. I already change the oil pressure sensor. And I can't find a diagram of my vehicle with the oil pump on it any where , can some one help?