Listen guys I have had my 1998 Z28 in my garage sitting due to a oil pressure reading of zero. So today I fire it up for the first time in a long time and the pressure reads zero. After I shut the car off the gauge raises to normal levels with the are and electronic system being off. I replaced the sending unit and it changed nothing. About a month before the car was placed in the garage on a stand still due to the reading being zero I had problems with acceleration. I was driving it and it had seemed to bog down at weird times. I would drive it and try to step on it and it would almost conk the engine out. But I was able to restart it and gte it back home. This was RIGHT before it had the oil pressure gauge drop to zero. I am wondering if it is the gauge itself or actually the oil pump. Seeing as when I had shut it off after the initial start and the gauge would rise to normal specs. Is it the gauge or the oil pump?

 

Put a temporary manual oil pressure guage on it, pull the fuel pump relay, and crank the motor over for a minute or so watching the guage. 0 pressure means oil pump is shot.