stalling/stuttering issues non driveable

[Passion 4 Speed]

I started to have this problem after my car been down for a month due to a blown trans, after i installed a fresher transmision i been having stuttering issues underboost. my car use to boost 14 pounds, but now it barely reaches 10. So i checked all my vac lines replaced the old vac lines on the turbo with new ones and installed new clamps on all the vac hoses made sure they were screwed on nice and tight.
did a quick test drive my car pulled much better , but then the second time the stuttering came back so after that i decided not to boost at all till i have the time and day to make a boost leak tester to see whats going on.
Well now its gotten so bad that i cant even barely drive the car! it would shut off almost any time i hit the brakes (kinda like when ## venting bov improperly). Under normal driving conditions it would slow down out of no where like the turbo just shuts down ,and feels like i just hit a wall jerking back and forth. This is not good esp in busy florida traffic! When it does act like this i would rev up the engine and hold the rpm steady at 3k and watch it go up and down on its own. (3k to 2.5Krpm) Then it jus died, and started back up again like nothing happened.
Which threw me off thinking that it was a spark issue i ended up buying new spark plugs and checking spark on all cylinders which all came out good.

Heres what i checked and done
All vac lines made sure they all had new clamps.
Installed caps on the egr valve, the ports on the TB, and on the air intake.
Boost gauge reads -20 at idle
A/f gauge reads one bar away from being rich while normal driving.
Car drives way better when the mafs is dissconnected for some reason. But i kno it vital to have on and hate seein the CEL on.
i do have spark and fuel.

I never had a problem like this and its bothering me alot, can a boost leak actually be this bad, or is it something more serious??

 

[GVR4592]

A boost leak can definitely cause serious driveability issue's. I would do a test right away.

 

[Menacing talon]

The car drives better when the MAF is disconnected? Id start with that problem

 

[Passion 4 Speed]

thanks for your input guys i really do apperciate it.
I ended up limping the car to my mechanic he's pretty good with dsms. He thinks its a fuel problem so he changed my fuel filter, and come to find out it looked like dirty water(brown colored) in there. After that i am able to drive my car normally and it boosts fine sometimes.
He also mentioned that i should change my fuel pump cause it too can be contaminated. I am going to regardless go for the walboro fuel pump.
But i still plan on making a boost leak tester cause im pretty sure i have one somewhere.
Hopefully i can figure out this problem asap.
I think its probaly my damn ebay boost controller, i have it set up correctly towards the turbo, and i cant gain or decrease boosts that controller never really work, the only was i was able to gain boost was by shimming the wastegate..right now its not shimmed cause its a newer 14b turbo and i got a mbc with it.
If i only had time...
thanks guys!

 

[Boostjunki84]

did you try to disconnect the boostcontroller and just run a vacum line?

 

[Passion 4 Speed]

thank you Boostjunki84 for that advice! when i went to do what u said i notice a tiny hole near one of the clamps on the vac line..cut that lil piece off put it back on and that was the end of my problems!! Cant belive a lil tiny hole on a vac line cause me this many problems. and what threw me off was these vac lines were brand new along with the mbc i would never suspected for them to come with holes or maybe be so made cheap.
thanks for all the help!

 

[Boostjunki84]

no problem. glad you got it fixed.