Engine 89 lx 5.0 popping/surging under load but idles okay.

Been going thru alot since redoing my intake. went with an edelbrock performer upper and lower, edelbrock 65mm tb and spacer, accel 19 lb fuel injectors,bbk fuel pressure regulator, motorcraft egr and iac valve, pro-m 75mm maf, new h-pipe, new cats, new o2 sensors and harness (had code 41/91 they are gone now problem still persists),replaced plugs, wires are less than 5 years old, new rotor on dist less than 5 years old but original dist. I try and drive it and get the popping out of what sounds like the exhaust and very poor acceleration and bucking. a week ago this only happened when the car warmed up and the check engine light came on giving me the 41/91 code. fixed the sensors,cleared the codes. but now its all the time , cold or hot if i try and move it the car just bucks like a bronco and pops out the exhaust. i can avoid this by driving it like an idiot and keeping the rpm high at like 2-3k while im letting out the clutch, once i get going it doesnt seem to pop or buck unless im at low rpm, but the power is for sure lacking thru the entire rpm band. All this is accompanied by a rough start after sitting for a few hours, i go to turn it on and it just turns over. i do it a couple times,like 2 or 3 key turns for about 3 seconds each, and eventually it roars to life to 1500-2000 rpm like you would expect then drops down to a low lumpy 650 idle instead of 900ish like it should and slowly gets better and better over 1-2 mins eventually leveling out fine i can shut it off and start it back up with no issues, its just when it sits for a period of time. My next guess, and thats all it would be, is the fuel pump is no good. Check valve is blown so the lines dont hold fuel which would explain why it wont start after sitting? popping and bucking because of lack of fuel? i put the new MAF sensor in today and it seemed like it made the problem way worse, like almost undrivable, is the car demanding more fuel because of the new maf and the pump cant keep up or did the problem just get worse on it own and its a coincidence that i put the new maf in around that time? im at a loss here. since dealing with this ive replaced the 02 sensors and harness, cats, set base idle, bought new iac valve, played with timing from 10-14 nothing helped.

Ive pulled codes. Koeo nothing aside from all clear. Koer gave me 41 91 and i addressed that by putting new cats and 02 sensors with a new hpipe. Codes are gone problem persists. I guess i can try and pull again but all i ever got was 41 91 aside from the 11. I had egr codes but fixed those. I know it seems like im throwing money at it but these are all things i would have needes to replace anyways. Practically everything is stock with 240xxx aside from what ive replaced. Car has been in the family since 2000 so i know almost all the history and the time i didnt have it i have documented up to about 90k miles.

The car ran, idk about perfect but it ran before i started replacing parts with the intake. I tried to stay near stock with the new parts, 19 lb injectors 65 tb etc to avoid pissing off the ecu. But it looks like i did a good job of that anyways. Not going for a drag car just restoring my dads fox for a spirited drive on the weekends and such.