ok so I have had this problem from the day i dropped my engine in after building a ls/vtec block.It's a remanufactured short block new oil pump,oil pick up tube and gasket after looking at a service manual i found a oil head control orifice and the block i got never came with one so i thought that was it i took the head off put the orifice in re-primed my pump and started it I got 15psi @2k rpm ran it for a good 15-20 minutes then drove it around the block a couple times came back i checked my gauge and it read 0psi.I don't know anymore what it could be and hoping someone here might have a solution.I know i have new main bearings,new oil pump,new pick up tube with gasket,new head oil control orifice,new O ring in the head for the cam orifice.Any thing I might else be missing on the new block?Thanks for and advice

 

i had a ls/vtec seize up on me because there was no relief valve in the oil pump, but by the sounds if it thats not your problem if you had oil pressure and lost it. i know it's kinda messy but can you take your valve cover off and start the engine, see if there is any oil going up into the head, could be a bad gauge?

 

Ya i checked the releif valve and it's good no burrs on it or scoring done to it and i have used 3 different gauges so i know it's not the gauge lol