HI....i stopped at a stop light driving home tonight an looked down an saw near zero oil pressure! I pulled off the road, an noticed that when i gave the engine gas the preasure went back up. I added a quart (it was a little low) an drove on home...the guage would read zero or near zero when idling or under braking..an norm when cruising....is something wrong witht he guage/sensor or should i park it an put a oil pump in? its the stock pump on a 87 5.0 with 58K on it..thanks for advise.