I have a 1990 bronco with a 351efi windsor.The problem i have is when i the truck it runs good,but after a few minutes the oil pressure gauge drops to nothing and the engine light comes on! When i fist start the truck,it fires up ,runs good with no engine noises or anything,just ater a few minutes the oil pressure gauge drops with the engine light coming on so i shut it off right away. Could this be my oil pump or maybe a faulty oil pressure switch? Has anybody else had this problem? Would appreciate any help and suggestions.

 

I had this problem and iotr was corrions on thw connector at the oil pressure switch.
As always with oil pressure problems, verify with a mechanical pressure gauge. The Factory gauge is nothing but an idiot light in the guise of a gauge.

 

It only happens when the motor is hot and idling in gear right? And as soon as you hit the gas a bit the oil pressure comes up? And the engine doesn't rattle or nock?