I had started my Cuda earlier this week to warm it up so I could check the valves hot, I noticed the oil pressure going down, 55 to 15 to and then back up to 120 lbs. (55 cold at two thousand RPM has been normal) and then back up several times and finally drop to zero before I shut it off. I had two of the intake adjusters break earleir this year so I figured debris had worked is way into the oil pump bypass valve. I have a dual line Milidon system with thier older cast aluminum pump, I remove the bypass valve and seen marks on it, it did come out easy with a pencil magnet though . I cleaned it up and put it back together, reprime it and then started it, walk around to look at the oil pressure gauge in the car and it read zero, long story short I took the pump off and found one of the bolts a tiny bit loose, put it back together after looking at the drive end and so on.Reprimed it and had presure priming, no pressure when running I ended up calling Milidon several times in this process due to it having pressure when priming it with a drill motor and no oil pressure when running I installed another mechanical gauge with a long plastic flex line so I could see it when priming and then put it in the car so the wife could watch both gauges, they had the same pressure readings on both gauges I ordered a set of new gears for the pump and the correct oil pump drive, according to Milidon that pump takes a 7/16 inch longer one than I had been running The old drive end looked like it was fully engage on the drive portion of the tip and the female end on the gear end look good also as far as drive engagement .I tried installing a 1/4 inch longer drive that I had and ended up with the same results . Murphy steps in while I'm working on the oil pressure problem and the MSD 7AL2 box takes a dive two days ago Luckily I have another MSD7C box so I swapped it into the car this afternoon and reprimed it,I had tried changing the bypass spring also in this process, took out a high pressure black spring that I had trimmed to reduce the pressure down to 65 lbs with hot oil at or above 6000 RPM and put in a new black spring that raised the priming presure up 15 lbs than before switching them. I started it up this afternoon after replacing the MSD and repriming it with good pressure, it still had no pressure while running Ended up removing the passenger side valve cover this afternoon after that to see if I could spot anything abnormal, I had checked all the drivers side pipes with a Infrared hand held temp gun and all four pipe where within 50 F of each other when running with intermitent oil pressure, all above 700 F. The dang #4 intake adjuster had backed out while keeping the pushrod under the rocker arm eating up the adjsuter tip and rocker arm and let the darn intake roller lifter lift up enough when running to stay out far enough up to let all the oil pressure blow out around it I replace the pushrod and adjuster and now have oil pressure I love Murphy, especially on trying problem like this NOT Oh well Another lesson learned the hard way, again Check the obviuos first

Damn, I thought you had a story about an AMC Gremlin X

Hi Cab-
I haven't talked to you in a while! I'm glad you go it figured out. After the last time we talked I ended up naming my old girl Murphy.
Murphy can be a real bit** at times!!!!

If you think that lifter may have bounced on that cam at all. You might want to pull that lifter and check it over real good. And our replace it and send the old one in and get rebuilt. It doesn't take much to hurt the roller bearing or the axle pin in those. Then once they are hurt you know what comes next.
You are a more than competent engine builder. I'm just lending you an extra set of eyes is all.

The lifter never came out of its bore, the pushrod was still sitting on the top of the lifter(Isky .180 offsets on the intakes) still and captured under the rocker arm side I guess that is why it would have pressure while priming and loose it when running

Plus where you were warming it up, it was basically just idling. So the RPM's weren't high enough to really give the lifter a hard enough smack to hurt it
But that still sucks that you had such a run around. I'm glad the problem is solved