gst feels like hits rev limiter at 4500-5000

ok so im going nuts here.:banghead: first off let me give you the set up.
shes a 98 mitsu eclipse gst. 5 speed tranny, 20g turbo from greddy , fmic with hard piping, 750cc inj. , afc (now un installebd) greddy type s bov, walbro 255 fuel pump, adj fpr, greddy exahust 2 and a half in from down pipe back with a high flow cat, 10 mm plug wires, ngk pluggs, have 10.1 vortec fmu but havent installed yet, greddy profec b boost controller, and evolution turbo timer, new maf sensor. and i think thats it on the mods.

ok so i had the car tuned 5 or 6 months ago i hit 315 hp @ 20 psi boost. and all was good for a couple of months. I babied the hell outta the car got on it once in a while but i take care of it.

ok so now the problem the car suddenly started feeling like it hits a rev limiter at 45oo rpm and wont rev any higher in any gear or in neutral.
and turbo is spooling perfactly no shaft play and no leaks.
the car isnt overheating.
there is no knocking or ticking from the engine. and i run 93 oct. fuel always
and use synth oil. changed frequently.
so i did pluggs and wires it fixed the prob for like a week.
i did tune up again and no fix.

im getting cel the codes i pulled are fuel trim malifunction bank 1 (p0170) , Idl. controll fuel and air metering (P0505), Manifacture controlled fuel and air metering (p1105, and Cylinder 4 misfire (p0304).
a friend told me to pull out the afc so we pulled it out and no fix. i turned the boost controller to 6 psi so as to not damage things but the car wil hold what ever boost level i set the contr. to with no boost creep and no lagg its great. but when i hit 4500 i hit a brick wall she just acts like rev limit. I cleared all codes and cel stayed off for 2 days but the problem was still present with no cel on.
we put on a new maf, no fix. compress test 150s to 160s across the board, boost leak test found no leaks. my ///// out // line on the boost controller was not on all the way so i fixed that and still no fix. i noticed that my wastegate actuater isnt moving at all on spool or blowoff i thought this was an issue so i tried to move the wastegate by hand and it wont move but i was told that was normal that it is hard to move and that as long as im geting boost that the wastegate was good and working. its an internal wg. i dont know if thats true but its ony a few months old
anyways im going to put new coils plugs and wires on and see what happens
but i doubt thats going to fix the issue.
timing is dead on. i have ratteled many brains arround here and no one knows whats going on. any advice would be appreciated. i tried resetting the ecu with no results. the only other thing i can think of is possably the ecu is damaged some how. but ya thats about it. let me know what you all think.
ohh and one more thing when i pinch off my return line off the fpr the car dies. I dont know what my fuel pressure is currently at but nothing was changed prior to having the issue. and yes i changed the fuel filter and no fix. :banghead: eeeerrrrrrgggggg.

750cc inj. , afc (now un installebd)

Hang on......you are running 750cc injectors and no fuel management?

yes car was runnin fine on the walbro , inj, afc, and adj fpr. i have the vortec fmu but not installed it yet. the car was running beutifully. the tune up today had no results ad i cant find coils had to order them theyll be here friday.

DO NOT drive that car as is man. For one, 750's are too big for the SAFC to run decent, hence the 315hp @ 20psi numbers. Do those seem really low to anyone else? That was bad enough, then taking the SAFC out was like 4 steps backwards in your walk to the solution. The car now thinks it is running injectors nearly half that size so you are running uber-duber pig rich, rich enough to have a thing called bore wash happen. Then you are hitting fuel cut at 4500-5000 RPM because the ECU doesnt realize the bigger injectors are there and at those airflow rates the stock 450's wouldnt suffice. The ECU then cuts fuel to prevent damage from knock because of the lack of fuel. Basically, you need fuel management.

Heres what I would do. I see you have some Vortech FMU. I am unfamiliar with this fuel management setup, but I can almost 100% guarantee DSMlink would be a better deal. I would get yourself a 95 EPROM ECU and DSMlink, then have a shop tune it again. My guess is on a good tune and 20 lbs of boost, you will see considerably more power over the AFC setup.

But whatever you do, get some fuel management before you even turn the car over again.