Correct fuel pressure at wot?

Hey all, new user here. Problem with my 96 XJ 4.0, (110K original miles) basically it won't run at wot or near wot. I've had the tank down to clean prior to this, installed new FP, cleaned the sock, had new filter and ran great. I let it sit for a long time and recently started driving it and at some point it developed a slight miss and bogged bad at full throttle. So, I changed the filter (was full o' muck) and the fuel pump, still left the old sock cuz they didn't have one in the store and the old one just looked a little discolored is all. So, after fixing some CCV issues, the thing is running very nicely, for a mile or two, then it develops a severe bog only at the wot conditions. Back it off and let it recover and it's golden again, no codes at all. I tested my FP, idle was 50, so taped the gauge to my hood and went for a spin... when I floor it the pressure drops to 30-ish. I can't find the specs for full throttle fuel pressure... is this normal? If so, I have read it could be CPS acting weird, fuel P regulator, coil, o2 sensor, grounds... etc. Any help much appreciated!

Fuel pressure is supposed to be maintained at 49.2± 5 psi. I think you have a fuel delivery problem

Thanks, I have a complete spare TB I'll try in case it's the regulator, if that doesn't work then (another) new pump and sock.

:crazy: Oops, fuel pressure reg not part of the throttle body. That caint be the issue anyway right?

That is correct. You should have a single fuel line to the fuel rail. If so, the regulator is n the tank with the fuel pump

Geeze.

Fuelab 56504-1 Black 40-80 PSI Universal EFI High Flow Bypass Adjustable Fuel Pressure Regulator
by Fuelab
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