D21 KA24E oil pressure issue
 

I have a '94 D21 with a KA24E that I replaced the timing chain on. I drove it for 5 thousand miles afterwards. It has 180K on the clock and it broke down on me. Noticed that no oil is flowing. I replaced the oil pump. I've removed the timing cover again to inspect everything, but I don't see anything wrong. I'm at a loss on this one. Only thing I can think of is get a rebuilt engine. I'd like to keep the truck. Any thoughts or ideas on the cause is appreciated.