Oil Pump Issues on 1990 XJ

I just did a full tear down of the 1990 4.0 and got it back together. I changed the rear main seal, valve cover, front main, timing cover gasket, filter adapter O-rings, and the oil pan gasket. I get it back together and fire it up to check for leaks and no oil pressure...I shut it off immediately, but I wasn't sure if I damaged the oil pressure switch. I unscrewed the filter and it was dry. I even followed the instructions to prime the oil pump with a flat blade drill bit, a bunch of extensions, and a power drill. I know I'm gonna have to pull the junk back apart and put in a new oil pump. I don't think I damaged the bearings everything inside the engine had Lucas on it and I have had plenty of luck before with a vehicle being part a while and everything still been lubricated weeks and even months later. I got a rebuild kit for the oil pump when I had everything apart, what my question is: There was a spring loaded valve that looked like a tear drop inside and was held in place by a retainer pin. It was a really tight squeeze getting the new tear drop piece in place and the plate that rests on the retainer pin. If those parts were a few thousands of an inch off, and fit to tight to move, could it cause the pump not to get oil up to the filter? I assume it pulls the oil up when the shaft rotates, then the valve closes sealing the pump so as it rotates, it pushes oil up and out of the pump, is that how the oil pump works? Or is the valve on the spring just serve as an anti-drainback valve to hold oil in the pump when you turn the vehicle off? It is 1990 XJ with a 4.0.

Make sure your drill is rotating to the right and you don't have it in reverse. I most always troubleshoot from simple to complicated. Sometimes the issue is simple.

I think the piece you are talking about in the oil pump is a over pressure release. Not going to swear to it. I've cleaned them up and made sure they weren't frozen before, never replaced one.

I've had trouble getting oil to the top before, it eventual works out. Now when I have the lid off the oil pump I pack it with Vaseline which really helps it prime.

The oil pump pumps air poorly, it needs oil or something in there to help it seal and displace the air.

Not likely the pickup tube came out of the oil pump, it comes out really hard, not like an old Chevy where you can knock one loose or off. I've never manged to get one out of a Jeep oil pump.

Fire your drill up and wind up those RPM's, give it a chance.

And lastly when you rebuilt the pump are you sure you removed the lid gasket? The lid to gear clearance is somewhat critical. If you got two gaskets in there it is going to cause issues. On worn gears I sometimes throw the gasket away and seal with a tiny line of Permatex.

I'm out of ideas.

For what you paid for the rebuild kit, you should have bought a pump, which is what I advise you to do now!
The most common wear items in a pump are not serviceable. You should also be pre-filling the filter, a dry filter is one of the most common reason for filter failure!