The old Brick started her oil pressure light flickering after a freeway run last week. I replaced the pressure switch and checked the wire and thought it was going to resolve it. After another high speed run; I still get a flicker at idle. I have noticed a loafing un even idle and if i give it a bit of gas, it stops flickering. I noticed that the idle speed when coming off the gas, dips low and I think that could be what's causing the low pressure. how can I bump up the idle? Anything else I should look at? The engine has 159k well cared for miles, so it shouldn't be the pump, right? Thanks in advance!