Ok, according to my little Haynes manual Fuel Pressure w. KOEO should be 41-47 psi, at idle it should drop 3-10 psi, putting it around 31-37psi.

Fuel pressure tests at 35-36 psi KOEO, and on start-up, it jumps to about 41-42 where it holds at idle. revving causes it to drop slowly, 3psi or so in total.

Is that normal? lol.

The car is giving me a random cylinder misfire code and I've run down and replaced everything except the opti in the spark side of things. All the plugs look fine though, none are coated in gas or carbon or anything else indicative of the mix not firing.. I dunno. I just ordered a new opti but I'm trying to exhaust the other possibilities.

*shrug*

 

Fuel pressure with the vacuum line off of the regulator should be around 40# or so. Attaching the vac line to the reg at idle should pull it down to around 33-35#. The regulator adds pressure as manifold vacuum decreases...so at WOT when there is very little vac the fuel pressure should be about what it is with the vac line removed.
Revving the motor slowly with no load may increase vacuum a bit and thus pull the fp down a little more than what it was at idle.
So your in the ballpark, fp is not your problem.
Opti would be a good starting place and make sure you have no arcing by looking around at the motor at dark and see if you see any sparks/arcing, revving the motor.

 

Thanks for you input, much appreciated.

So far Ive done the following;

New plugs (two sets actually)
Ohm Checked and looked for arcs in the plug wires
New MAp
New ICM
NEw Coil
redid coil grounds
checked Opti pigtail
Unplugged o2's (I was told to try that.. *shrug*)
replaced many vac lines and hoses
new TB elbow
Cleaned maf
Checked, cleaned and re-oiled filter (K&N)
Checked oil and antifreeze for cross contamination

Absolutely NO change in condition. If it aint the opti, I dont know what it could be. I'm going to redo the coil grounds on more time and check for spark at the individual wires one more time, then I'm gonna yank it all apart while I wait for the opti to arrive.

One thing.. I was throwing a code in relation to the Bank 2, downstream o2. The damn thing is WELDED (i'm not joking) in place so I cant get it out to replace or swap it.. but it sure thinks the Cat isnt working correctly. The code was like Catalyst Below Efficiency Threshold. Oddly enough, it went away on its own a month or so ago.. BUT could a clogged cat build up enough pressure in the mani to force gases back into the combustion chamber during overlap and louse up combustion or flat blow out the spark? The cat isnt visibly damaged and when I rap it with a hammer I dont hear anything rattling, I know that doesnt mean its good though, just not obviously bad.

Just a thought. Ive been chasing this problem for something like 2 months now, closing in on three and its eating me alive.

 

I'd take a cutoff wheel and die grinder and carefully cut the weld so you can remove the O2, or take it to a muffler shop along with a replacement AC Delco O2 and have them cut it off and weld in a new bung and install the O2, at least get that taken care of as you never know how it may be relating to the other issues...sounds like somewhere in its past there was an issue there...maybe they stripped out the threads and just welded it in rather than fixing the bung.

 

"maybe they stripped out the threads and just welded it in rather than fixing the bung."

That is exactly what happened. I tried forEVER to get the damn thing out and couldn't figure out why it wouldn't budge, until I realized it was welded all along the seam. How I missed it to begin with is beyond me. I'll have to drop the Y pipe and just have it cut out and replaced.

I called the guy I got it from and asked him about it and he was like "Yeah, the threads stripped out somehow so I had my dad weld it in".. sigh.

 

a clogged cat most certainly creates a ton of pressure than works its way back and has nowhere to go

for example when my cat got clogged it ruined the EGR valve turned my plugs black and a couple plugs even came loose... but it also felt like the car literally lost about 100whp icould floor it in 1st gear and it would take 10 seconds just to get to redline... a shop took out one of my O2s and low and behold some of my power came back because now the exhaust had somewhere to exit (the O2 bung was open)... hacked the cat off and put a new one on, changed the plugs, deleted the egr and everything was good

 

Your fuel pressure test results seem backward. Start the engine and let it idle. Pull the vacuum compensation line off the fuel pressure regulator, and cover the end so you don't have a vacuum leak. The fuel pressure should be in the range of 41-47psi, with 43.5psi preferred. Reconnect the vacuum line, and the pressure should drop proportional to intake manifold vacuum... 6-8psi with a stock cam, as little as 3-4psi with a hotter cam.

Then you need to check the pressure with the engine under full/max load. Tape the gauge to the windshield, take it out on the road and run it up to max load/rpm. The fuel pressure should not drop below 40psi at WOT. That shows whether the pump can supply the engine's max fuel demand.