98 GS-T misfire/backfire

Alright guys, I'm a noob but I did try the search. Here goes...

I acquired a 98 GS-T Spyder from some people that owed me money. The guy put on a new EVO III big 16G turbo, intercooler, Greddy BOV, Apexi N1 downpipe, boost controller, fuel pump, cold air intake, etc. It also has the first generation engine. The previous owner couldn't afford getting it tuned right. That's where I come in.
The car starts and idles fine and is smooth with moderate acceleration. It was throwing code 1103(MAS) so I replaced it. Still coughs. Also code 1400(EGR). The mechanic thinks the code is coming up because of the Gen1 engine and thinks it's not our problem even though what I believe is the EGR has all 3 nipples uncapped. He thinks the problem lies with the BOV.
What's happening is on acceleration, with positive boost(usually above 15lbs), the car will cough/stumble. Usually without warning. Where it coughs varies. It seems pretty consistent in 3rd gear at around 15lbs boost and 4500rpm or so.
What it's also doing is blowing off the hose that connects the piping going into the intake. It did it once when I got it to 19lbs boost. This last time it went at 16lbs. I'm not so sure it's the excessive boost doing it, maybe the misfiring. The BOV has the upper nipple piped back into the intake. The lower nipple has nothing on it. Is this normal?
There's also a vacuum line from a module(blue) labeled "boostXs" and you can adjust the boost with it and the other blue module next to it. The vacuum line goes to a T, with one end of the T going to the wastegate and the other end is connected to nothing. Doesn't seem right to have it open on the other end. The same module also has a line running to what I believe is the cold air intake. I've tried adjusting the boost on both blue modules down as well as the BOV so I don't blow the hose off the intake piping but it seems my adjustments do nothing.
The previous owner knew of the misfiring and said he was told to get a code reader and just erase the code. I haven't found that to work. Any help is greatly appreciated! The car is up for sale and I want it working right when someone looks at it. Thanks.

Well that sounds like a mess. That boost thing that goes to a T fitting is your boost controller. One end should go to your wastegate and the other end should go to somewhere in the intake piping after the turbo. Without both lines hooked up, your wastegate will never open and you will boost too high, which is very dangerous to the engine.

With all of the mods that you mentioned, I didn't see anything about bigger injectors. If you are boosting the E316g to 16-19psi on stock injectors, that could be causing you a big problem. Also, you mentioned the intake popping off. If you have a boost leak like this, that will also cause your car to stumble. Did you notice any black smoke coming from the exhaust while boosting?

All of the vaccum lines should either be going to somewhere, or capped off accordingly. Open lines and fittings will almost always cause the car to run rough.

Thanks for the quick reply. I'd read that bigger injectors are needed, but I just don't know if they are. Anything I could look for to find out?
No black smoke DURING boost. When the MAS was bad, it'd blow black when it coughed. It just coughs out now without smoke.
I'll make sure to look for a nipple that looks lonely after the turbo. So it sounds normal to have the lower nipple on the BOV uncapped? I read a thread that said to cap it, another that said to uncap it.
I guess with it boosting too high it's a good thing the piping is blowing off first, huh? wow. Thanks again.

This is what I'm seeing. Fresh air into turbo, gets compressed and piped back down through to the intercooler. In the stretch of piping before the intercooler there's a nipple that already has a line going to the boost controller we were talking about. It goes into the bottom of the controller. The line that T's is coming off the side of the same controller, with one end going to the wastegate and the other to nothing.
The injectors look stock, but I just can't say for sure.

Ok the boost controller has two nipples on it. The bottom one should go to your wastegate actuator. The one on the side should go to an intake source(This being on a TurboXS) It's debatable weather you should T it in with the BOV line or have it somewhere in the intake track. I did mine in the intake track. Now the factory T-25 came with a nipple on the compressor housing which you can hook the line up to with no hassle. The 16g didn't come with that so I had to drill a hole in my j-pipe and tap in my own nipple. I'll throw in a pic of this.

With your BOV, as far as I know, there should be only one nipple coming off of it and that should hook up to the intake manifold.

My suggestion would be to first get the boost controller figured out and lower your boost. But just because you set it low doesn't mean to go flooring it everywhere either. The 16g's are known for their boost creep. Especially with a bigger aftermarket exhaust. Mine did it right on up to 19-20 psi eventhough I was set at 14.

Second, make sure you get all of your fuel mods installed along with something to control the injectors ie. SAFC, DSM Link, etc. Then you can begin to crank up the boost to suit your setup.
http://i143.photobucket.com/albums/r149/badeclipse/ughsdasdf.jpg

Well it sounds like the boost controller is hooked up backwards then. The bottom one is going to the intake(kinda like your picture but it's further downstream from the turbo) and the one off the side goes to the T with one end to the wastegate. I just switched the two, drove it and no change. Get on the throttle a little easier(less than 10lbs) and it goes fine. What I got was fluttering(about 15lbs) before it popped, kinda like it was missing. I've run it up around 17lbs steady without any problem. I can't figure out why sometimes it coughs, sometimes it doesn't.
The BOV for sure has two nipples. It's a Greddy, not sure if it's the type-S everyone talks about. The lower nipple is uncapped, the upper piped into the intake manifold.
How do you post pictures on here without a link? I can get pics of the BOV, etc.

Your BOV is hooked up correctly. The lower port is just a vent.

What's happening is on acceleration, with positive boost(usually above 15lbs), the car will cough/stumble. Usually without warning. Where it coughs varies. It seems pretty consistent in 3rd gear at around 15lbs boost and 4500rpm or so.

the "problem" you are describing IS fuel cut, your motor is trying to protect itself when you begin to push more air into the cylinders then your factory 450cc fuel injectors can provide for! without a boost controler on a E316G turbo, you will reach fuel cut rather quickly in the 4500-5k range under boost in all gears! just FYI, their is nothing wrong, infact, its your car trying to avoid a more serious problem! :2cents:

What type of injectors do you guys suggest and what do they run$$$?

680s to be safe. Price will vary greatly depending on where you get them. Extremepsi.com sells them for $270, I've seen them on dsmtuners.com for between $125-200, or you could try ebay or probably even a member of the board here has some extras.

EDIT: I assumed by your name that you were from somewhere in northeastern ND and in your profile it says you're from Moorhead. I go to school at NDSU, so if you ever need any help, gimme a shout, I'd be glad to help a fellow DSMer.

NDSU huh? I went to UND so I don't think we have anything more to say to each other. haha Hey thanks for the reply though. That's way cheaper than I thought but I'll likely sell the car without bigger injectors. If you know of anyone in the area looking let me know. It's listed on autotrader too. If you check it out, let me know if you think I'm way off for asking price.

Haha, well it wasn't exactly my first choice in a school by any means, and nothing beats Sioux hockey coming from a dominant hockey town. I'm assuming you graduated already? And I'll definitely put the word out there for anyone looking for a dsm.

Haha, yeah I graduated a few years ago. If I was still there and single you can bet I'd be keeping this car for sure. It looks awesome with the top down and flies even though I can't stand on it. I'd toss the stock rims first thing though.