GSX driving me crazy

OK guys, I am dangerously mad at the GSX right now from trying to figure out how to fix it so I decided to post my problem . OK, I got new couplers HKS ones and a reducer from turbonetics for j pipe of the turbo to the intercooler pipe. New huge T-bolt clamps holding the pipes together. No boost leaks anywhere. Intake is sealed shut since I am venting. I cant get over 9psi of boost. Its driving me crazy. I went to a local performance shop and the guy wants almost 2k to fix it since he will need over 25 hours of labor. I really cant figure out why I cant boost high. When I floor it, it like goes foward till it hits 9psi and then draws back and makes a loud exhaust sound like a honda. I was woundering, are wastegates adjustable and if ours are adjustable. Also I went to another mechanic and he said that I am getting fuel cut. WTF fuel cut with 16G at 8 pounds sounds like bullshit to me. But incase I am gettin g 660cc injectors and a fuel pump at the end of this month. I got safc but still waiting to arrive. But any ideas why I cant boost over 9psi, can a small exhaust leak between the exhaust manifold and turbo cause this? Wastegate problem? Throw me anything so I can check it since I am clueless. Oh by the way, I have a bad ISC but I dont think thats the problem. Almost forgot, my car's exhaust is black, black smoke comes out when i drive I guess but I never saw any, but the bumper is black. So i was thinking I was running rich but my turbo is not big and my boost is low. How can I check if my turbo is burning oil if it is.


Sorry for all the question but I am desperate to get this car fucking boosting right. If I cant fix it in a 1 month or some one around here cant fix it under about 1 grand I am selling it.

Sounds like what can happen if sonmething blocks the intake. Is there sonething blocking the inlet to the turbo? For example, that little rubber spacer that goes between the stock intake tube and the compressor inlet?

Back in the day, before I even had a boost gauge. I had an exhaust leak and it felt like my car was barely boosting and it wasnt running too smooth. I took my heatshields off and my exhaust manifold had black shit on the edges of the head. I tightened the manifold up and took it for a drive. It was so much quicker, sounded good, was boosting more( I assume). The throttle response was much better too. Make sure all that stuff is tight, manifolds, nuts, bolts, etc. Check around for "black sute"(exhaust leak black dust).

How high did you pressurize youre intake when you boost leak tested it?

I took that little rubber thing off the turbo and used a HKS coupler instead. I dont think anything is blocking the intake since the car hits boost fast but just until 8-9 pounds and then it just stops to accelare fast. I forgot to mention, car is backfiring loud as fuck if I rev it to like 5k. It backfires almost every time I rev it high and the back bumper is black. Also I was woundering, I know some kids around here and they all have turbo gauges and their VAC is at -20 and mine is at -10. OK, is my boost controller not reading right or what. I am confused.

10 is pretty low. You're obviously running rich for one reason or another. Bad O2 sensor maybe

my vac idle 20-25 is that normal ?.

Idle vac on stock cams is usually 18-22. With cams it can be very low. I used to get 14-15 with 272s on the DSM, the EVO with 272s gets 10-12, some people with 280s are reported about 8".

Ok, so i am running rich. I ordered a SAFC2 but it still hasnt arrived. I cant figure out why my vac is so low, why i am running rich. I am really out of ideas. Is there a way to diagnose the O2 sensor. I dont want to go and spend money on something that i might not need.

Dont give up your gsx man, I know its moneys pit, my tsi have transfer case leak, and that make me really worried right now, but good luck to you man.

Ok, so i am running rich. I ordered a SAFC2 but it still hasnt arrived. I cant figure out why my vac is so low, why i am running rich. I am really out of ideas. Is there a way to diagnose the O2 sensor. I dont want to go and spend money on something that i might not need.
Checking your trouble codes is a good start. My oxygen sensor cost me $2 at a junkyard.

The little tab at the top of the oxygen sensor electrical connector is your reference point for being oriented right side up. It goes....
12
34

Those are the pins left to right, top to bottom.

The oxygen sensor resistance on pins 3 and 4 changes according to temperature. It told me what the temperature was at the junkyard that day.:grinyes: Check that when it's cold, at around 68 it should be around 12 ohms.

The other test is not as simple so I'll post that later if that turns out ok.:smooch:

I have an idea... give it to me :).

I dont have any idea what could be causing you to run rich other than bigger injectors and no fuel control, but a vac leak will cause the vacuum to be low wont it?