Stutters at 1500 rpm and runs crazy rich

[sleeping95gsx]

I have a 95 GSX, and i have a few mods done that would be transferable when i do the 6 bolt swap. Well, i driven the car 3 times in the beginning of May, and ive been working on it ever since.. Heres my mods thus far:
EVO III b16g
EVO III Exh. Mani.
Megan Racing 3" down pipe (no cat)
3" exhaust i built myself with Vibrant muffler
o2 simulator
Topline revised lifters (had a clogged lifter when i bought the car originally)
Turbo XS MBC
FMIC (short route)
Greddy Type S BOV
K&N Filtercharger (came with car)
FAL fans with on/off switch (came with car)
Walbro 255 fuel pump
Aeromotive FPR with liquid filled gauge and tapped rail
The rest is mostly cosmetic; carbon fiber hood and mirrors which came with the car, i put the necessary gauges (boost,oil press., air/fuel, and volt), and it also came with Tokico Blue Shocks and Tokico springs. So here's the problem..i start the car and it holds farely well at about 850-900 rpm, it smokes slightly..as I increase the rpm to about 1500 it starts to stutter and more black smoke comes out..from 1500 to about 2200ish it'll stutter and from about 2300 up it rips and blows eardrums out, but also dumps out black smoke. Ive recently replaced the spark plugs with NGK plugs with stock heat range from machv.com, replaced the wires with bosch ones. I ordered a new 90 elbow for the J-pipe to lower IC piping because the stock one doesnt fit to good, it seems to hold boost fine but im also going to perform the leak test this wknd; the fpr gauge holds at 37psi at idle. If it doesnt work after the leak test and plugs..what else could it be?! Bad valve seal? piston rings? i have no idea. The help would be greatly appreciated!

 

[dsm_Crazed]

Well that really sounds like a boost leak. Do the leak check and then let us know how it goes.

 

[sleeping95gsx]

the new silicone elbow is coming in on tuesday so im going to wait until then to do the leak test

 

[sleeping95gsx]

did the test and its still running rich. so the new plugs and leak test didnt help. im going to have the car taken to the performance shop by me for them to look at it. ill post when we figure out wut the problem is

 

[DSM4me44]

The vacuum line off my fuel pressure regulator came off one time and my car experienced some of what you are talking about. If you have a boost leak that big, you should be able to find it quite fast. Any check engine lights yet?

 

[MuffinMan7580]

Sounds to me like a bad MAS.

 

[sleeping95gsx]

Nope no CEL's, and is there a way i can check my MAS? when i bought the car it had the K&N filter charger on there, and its still on there, but its still the stock MAS plug that goes on to it. Before taking it to shop, im going to grab my friends OBD II and see what comes up. Ill keep you updated

 

[sleeping95gsx]

The guy at the performance shop i went to said the boost leak test is kind of pointless..because if i pressurize the system he said the bov would release air and if it went into the engine it would leak somehow to (i forget how he said it would)..i dont know if hes just trying to get me to bring my car in so he could make some extra cash or if hes telling the truth..wut should i do?