Fuel pressure regulator?

Ok, so my truck has been running pretty rough here lately, I have replaced the plugs and wires, mass air flow sensor, Ignition coil, and ran sea foam through it. My friend came over last night and hooked his computer up to it and we got 512 (Ithink) which I believe is No Codes In Memory. We also ran a fuel pressure test. The static pressure has me kind of puzzled. As soon as you turn the key on, the pressure jumped up to 35 psi but within a second, it drops to 6 psi. I believe the specs call for 35-45 psi (key on engine off) The fuel pressure is also a few pounds low while the engine is running too. With the engine running I am getting like 24-26 psi. I think the specs call for 30-40 psi here. (Key on engine running) Today I pulled the Fuel pressure regulator off, it was holding pressure to the fuel rail. The diaphragm is not leaking but I don't know if there is anything else to check on it, it is holding vacuum, and has good vacuum to it. Any suggestions would be helpful.
Thanks in advance

The fuel filter was recently replaced. I have also pulled the tank, flushed it and cleaned the sock.

Yea I googled the pressure specs last night and got a result of 35-45psi while running and 30-40psi static but that might be wronge im gonna do some more research

Ok will check that out tomorrow
about the low fuel pressure, and loss of power, will a leaking injector cause both symptoms together?

Fuel pump runs continuously
Changed fuel filter and fuel pressure regulator

Well Doc, you're real close, it always starts up great, but yes, it runs worse under higher ambient temperatures. After the engine warms up, it does get better. When the engine is cold, I have to pretty much floor it when pulling away from a light. It does better at higher rpms than if I would pull away from a stop normally. I have noticed some carbon buildup on the outside of the bed above the tail pipe. It actually doesn't have any cats on it. They were removed before I got it.

When I first turn the ignition switch on, fuel pump used to run 3 to 5 seconds then shut off till cranked, runs continuously now, act like maybe too much fuel or not enough when turning over but not starting.

OK Doc, so I did the plug thing, cycled the key about 30 times then pulled all six plugs. None are wet although they are brand new, four out of six have a light white burn to them while the back plug on both sides look new besides a little black carbon on the couple threads that stick through the bottom of the heads. So unless I'm doing the test wrong, I dont have a leaky injector. What would be my next step?

Am thinking about changing throttle air bypass valve next, unable to scan for codes on this '93 Ranger. Changed fuel pressure regulator, the fuel pump came on then off when ignition turned to on, cranked up fine, revved up fine, I drove about 2 miles and check engine light came back on, ran poorly when accelerator pressed past half way down, came back home, turned off, turned key to on and fuel pump running continuously again?

How do you change fuel regulator in 1990 Ford ranger

SO, just to be sure of myself, I ran the plug test a second time, this time leaving the key on a little bit longer each time I cycled it to make sure the injectors were getting fuel to them. I got the same results as the first time. I'm leaning pretty far towards the fuel pump being the problem. If I get low pressure to the rail while its running, and lose static pressure, and the fuel rail and injectors aren't showing any sign of leaking, while the fuel pressure regulator isn't showing signs of failure, that would leave the fuel pump being faulty, or ECM problem. I also unplugged the O2 sensors and MAF sensor and didnt get any change from them being out of the equation. Should I go buy a fuel pump?