Put MBC in and it doesnt do anything

[95GSTRaCeR]

I have a 95 GST. The only mods I have done is a HKS Super Sequential BOV and I put a 14B in. I was told that it should boost around 8-10 psi stock. Before I put the turbo in it boosted around 5-7 psi. After I put the turbo in the most it would boost is about 4-5. So I bought a MBC off ebay and installed it, but only one problem, it didnt do anything at all. I can still only boost 4-5. I am almost completely sure I installed it right.... Any ideas why it wont boost any higher?

[Import2nr99]

I'm looking to do the same exact same mods to my gs-t, until I get the money for an evo 16g and a fmic. Let me know how everything works out for you. Also any suggestions on how to make sure I don't have the same problems as you would be greatly appreciated!

[rysbrnr]

Something might wrong with the car besides the boost controller. Bone stock boost on your car is 14psi...on a 2g DSM with a T-25. Check for any boost leaks from the turbo up to the throttle body. Also, check and make sure the actuator rod is connected to the internal wastegate.

If you've gotten used to driving your car this whole time seeing only 8-10 psi at best.... just wait til you drive it at 14psi or more.

[95GSTRaCeR]

i have done a pressure check and there are no boost leaks. As for the acuator rod it is connected, but how can I check to see if it is opening properly?

[FourG63 97GST]

How did your setup the MBC?

[BoostedSpyder]

try adjusting the controller...

[89Turbo944]

I dont thin k that the problem is the MBC because you were not seeing full boost even before it was hooked up. Like stated before you should be boosting 14psi stock.

It sounds like a leak but you said you checked for one and found nothing.

It sounds like a more serious problem than just a boost controller. Take it to a mechanic and have it looked at.

Good luck

[BoostedSpyder]

14 psi on a t-25... what's stock for a 14B?

[FourG63 97GST]

11.9

[rysbrnr]

There isn't really a "stock" boost setting for either 14b or T-25. That just depends on the spring inside the wastegate actuator and the factory boost controller solonoid. How much boost either turbo can make isn't really the issue in GSTRaCer's case right now since his car not even seeing 8 lbs.
You can check your actuator by blowing compressed air into the nipple. It should open around 9 lbs (I think that is the pressure rating of the spring in it). Also make sure that when the actuator closes, it closes the wastegate all the way.
Another way you can test it, which is kinda dangerous if you're not careful, is to un-hook the hose to the wastegate actuator and drive it. But you HAVE TO WATCH THE BOOST CAREFULLY and not let it spike to 17 psi or more. If it does spike that high, that means the wastegate door IS sealing sealing like it should. But it SHOULD also open it sees boost (at your chosen level).
It's kinda hard to tell exactly what's going on with the car so you're gonna have to be a little more descriptive. You said you checked for leaks before. How did you do it? You cannot inspect for leaks visually. You have to use compressed air. If you don't know how to use air, there's a simple technique for doing this. First, remove the intake so thatall you see is the turbo inlet. Next step is to find something to cap off the inlet to the turbo. Then, somehow rig up a fitting on that cap so that you can attach an air nozzle from your air compressor/pump. [You could also just hook the air nozzle to the little nipple right after the turbo, while having the turbo inlet capped off] Once you do that you can start to blow air into the turbo's inlet. This will simulate boost without having to drive the car. You shouldn't be able to hear any air leaks. If you hear some air leaks but don't know where to look, spray a solution of soapy water in the suspected area. you should see bubbles coming from the leak. Fix the leak.

[BoostedSpyder]

i was just clarifying the stock pressures... but i do heavily agree about the boost leak presence. especialy aroung the BOV, where most major leaks are. are you on stock intercooler piping?

[95GSTRaCeR]

I forgot to mention in my first post that along with the other mods there is a whalbro 255 pump in it.I checked for leaks by making the tester on www.vfaq.com . I did have leaks around the bov and from an actuator thats under the battery tray. I fixed the bov leak. The actuator was cracked, we put jb weld on the crack, and no more leak from there. As far as anywhere else, I couldnt find any. Yes I am on stock intercooler piping. Someone told me that I might have an ignition problem, any ideas behind this? I have had this problem ever since I got the car and have done endless searching and still cant figure out how to get the car to boost higher. Any help will be greatly appreciated.