Oil pressure problem with 93 chevy silverado ?

My problem i am having is with my oil pressure.When I first start my truck the oil pressure is fine but after my engine gets hot the oil pressure get low,very low.I never hear any clattering from my engine when this happens but the engine will backfire.it seems that the timeing is off.can anyone tell me what might be causing my problem.maby a simple fix?Oil pressure problem with 93 chevy silverado ?
when the oil sending unit is getting weak it will still work when it is cold and the oil is stiff but when it warms up it leaks internally and then shows low press. it is very common I have replaced many of themOil pressure problem with 93 chevy silverado ?
Low oil pressure has NOTHING to do with the backfire.





Have you replaced the fuel filter yet?


Checked the fuel pressure from the pump. (in the gas tank)





ADDED:


Oh, I just thought of this.


GM uses a oil pressure switch behind the distributor to shut off the engine if the oil pressure drops too low. So, it could cause it to backfire by shutting off the fuel pump.





Try changing to 20W-50 engine oil. and Fram oil filter.


It's thicker and will maintain higher oil pressure.
could be the oil pressure sending unit or somethings wrong with your oil cooler
start with plugs that will make it backfire have the oil pressure sending unit checked