oil pressure drop on 1994 Dodge Ram 2500

I have a 94 ram 2500 with a 5.2l engine that had starting issues, that problem has been solved but now at an idle the oil pressure drops to zero and when given gas the pressure comes back up. to fix the starting issue we replaced the dist. cap, rotor, plugs and wires, i was wondering if there might be something we knocked loose or something, any advice would be greatly appreciated.

Asked by for the 1994 Dodge Ram 2500
the oil pressure switch is behind the distributor. i would change it anyway and do a manual oil pressure check to verify.