Oil pressure gauge variation on 1994 Dodge Ram 1500

When I start the truck up the oil pressure gauge reads normal. When I accelorate the oil pressure gauge drops to almost nothing. If I let off teh gas the pressure returns some. Is this a sensor issue or an oil pump issue?

Asked by for the 1994 Dodge Ram 1500
I've seen this before in high mileage trucks of varying makes. In most cases the oil pickup screen (attached to the oil pump)is/was clogged, allowing just enough oil through at low RPM's, and very little at higher RPM's.
The oil pan will have to be pulled to verify the problem either way.
Thanks!! I had not thought of that as a possibility.