I hate when we are working on something and then all the head scratching starts. I understand. I would be sure the rubber O ring on the snout of the pump is sealing. Maybe smear a gob of grease around the O ring and reinstall the pump? I'm guessing, but at this point you have to throw everything at it to figure it out. I had a bad sealing one once on a Milodon pump and every time i changed oil, It would lose prime.

To the best of my recollection, here's everything I did
- took new pump out of box
- sprayed it w/ brake cleaner externally and internally
- tightened small bolts that attach the rotors to the rest of the body
- removed bypass valve to verify spring type, inspect, and verify smooth movement of pressure relief valve after oiling it; compared to pump I just removed and noticed no differences
- poured oil into rotors and spun to verify freedom of movement; compared to pump I just removed and thought it "felt" different, but hard to explain...
- reinstalled bypass valve w/ original black spring that came with it
- installed oil pump
- pre-oiled new K&N filter and installed
- fired up engine just long enough to see it wasn't building any pressure (ZERO)
- pulled distributor & oil pump drive; no issues w/ oil pump drive seen
- chucked up pump priming rod and went thru a couple of rounds of priming the pump; noticed the pressure was only going to about 20 PSI which ASSumed was because of the low RPM of the drill... but still didn't make sense, especially cuz the oil was cold
- reinstalled oil pump drive & distributor
- fired up engine just long enough to see it was only hitting about 20 PSI peak, but would then start dropping

At that point it was about 8:30 PM, so I called it a day and took the dog for walk. Figured I'd consider what to do "tomorrow" (today) and go from there... or not, depending upon how I feel.

Oh, I painted the new pump black cuz I couldn't find any of the Street Hemi orange I had used to paint the rest of the engine previously. I'm sure that's the problem... f-ing Emo oil pumps are so tempermental

Are you sure it isn't the gauge?
Doug

Ok, you have a new Melling M-63HV oil pump on it in the standard configuration. The oil drive is turning it. We have to assume it works and the gauge is reading true. So, a new oil pump, if the oil pickup is submerged in oil, and has no air leaks on the suction side, will pump a massive amount of oil. So, I only see 2 possibilities here. Either it has an internal oil leak on the pressure side (and it's big), or it is sucking air. It can suck air from a cracked oil pickup tube (above the oil level), a bad gasket seal between the oil pump and the block, or as stated above, a bad o-ring seal on the drive boss that sticks into the block. Yes, there is other weird and strange things that can happen but I would think in 99% of cases it would be one of those things.

I agree 100%. Not much else it could be. Maybe the pick up tube cracked at the thread like i have seen some do. Hope you find it. Crazy.

As a quick check that doesn't cost alot, try a different oil filter. Put the K&N upside down in a clean plastic bag, and reuse it later if it is still good.

Anecdotal nonsense:
A friend (who I know personally and trust to not BS me), had 0 oil pressure after an oil change with one.
It's probably not that, but it is worth eliminating, in case you didn't already do that and I missed it.

Definitely try at least two gauges before getting into it too far.

I always have to use a thicker substance there like vaseline or grease, and have had no luck at all pouring oil into the pump.
I can never get them to prime with oil alone.

FWIW, I won't have any updates on this for probably 2-3 weeks cuz I need to focus on some other things for a while. Thx

Keep us posted !!!!

Absolutely; I'm sure anything I find will result in a post either here or in the For Sale section...

No updates cuz I broke & dislocated my left index finger about 3 weeks ago. Typing is bad enough, but wrenching is pretty much a no-go for now...

as my old man would say : "lay your pinky finger on the bench, and i'll hit it with a hammer ! you'll forget all about your [insert hurting part or place here] !".........
i know how tough wrenching can be with "hurting places", as having MS, i have to deal with this on an everyday basis.
get well soon sir !

Getting old is heck...I have a torn rotator cuff and labram from putting a trans in my car..I fell your pain

Wrenching can be good therapy. Therapy can't simulate a lot of things wrenching requires. I lost fine motor
skills on my left hand, secondary progressive here.

I to Have MS, I try to keep doing small projects & keep moving, BUT getting older WITH the MS pain is,,, well ,,,, just a PAIN lol, I laugh at myself so I dont cry , My Charger is names Brain Damage for a reason

how well i know what you go through Charlie !
therapy is good, but wrenching or working with your fingers helps tremendously with motor skills.
and yes, it's a REAL PAIN for sure !
i help myself by saying : "no matter how bad i have it, people out there have it worse than me, and those folks are the ones to be concerned about !"

When I feel pain? Think to myself my body is telling me a lie. And keep going.
Doug

kind of what i have been doing for years.
however, the older i get, the shorter the time period i can do this before it just becomes too much............
it's better than the "alternative" , i guess.........

I thought pain was natures way of reminding us that we were still alive.

FWIW I have been dealing with the torn rotator cuff and labrum since May. Now its race season so surgery will have to wait til after April.

I remember one Saturday morning being in a coffee shop in SO CA out in the Mojave Desert when an old man made a statement to me about I better get tough if I planned on getting old. I laugh and thought " what are you talking about, Now I know, I. slipped and fell years ago out of the back of my pickup after cleaning the bed with solvent and soapy water, tore the ACL tendon in half under my right knee cap and waited to long to go see a doctor about getting it fixed , tore rotator cuffs in both shoulder, tore the upper arm muscle lose from the left shoulder joint, mashed fingers and so on
Maybe being tough isn't the correct answer to prevent hurting ourselves unintentionally

I had oil pressure issues years ago. Came and went as throttle was applied. Got home, pulled rhe pan, and there was that rag, in the pan sump, the one i thought i had removed!