Help! Won't Boost Past 4lbs. Fuel Cut???

[Jordanbutter]

So here is the whole story. I got a FMIC, leak tested it and found all the cuplers leaked, so I fixed that. Then the lower I/C pipe blew off, that was my fault cause I didn't tighten it enough. Then my SSQV blew off the flange because the C-clip was never put in there all the way (at least I think thats why). Ever since then the car would not boost at less then half throttle at about 5000rpm, also it was very chattery with boost, even though the gauge held at 9-10lbs. After getting a GReddy RS, I set everything up, drove the car around and all the sudden it just stopped and wouldn't boost past 4lbs. The car sounds like its underwater (bubbly, studdering sound), and pretty much just stops. I changed the Plugs and the wires are fine, I checked all the lines (boost/vac). I've done a boost leak test and can't find anything, so any and all suggestions would be helpful. Thanks for reading through the whole story and thanks in advance for trying.

 

[levee000]

hhmm my old tsi did that and it was from a vaccum leak and a bad injector on mine so u might wanna check everything again

 

[romeen]

I'm not trying to panic you but the sound you're describing is similar to what I experienced when my motor crankwalked and destroyed the crank trigger. It made that sound and shut down right in the middle of the street. Believe me, I hope that I am wrong and if I am I apologize for any stress caused. Other things to consider are pre-turbo exhaust leak or bad turbo. Maybe check to see if compressor wheel is spinning freely.

 

[TurboChrged93]

Any DTCs? A bad knock sensor will not allow you to boost much and will cause intermittent problems. Do a boost leak test but it would take a serious leak for you not too boost over 4 lbs and should be obvious.

 

[romeen]

Maybe an obstruction in your intake pipes.

 

[shiner6n]

check to make sure everything is plugged in right. no matter how stupid it sounds look for obvious unplugs first had a similar problem after i put my intake on. i just forgot to plug in the mas

 

[Jordanbutter]

Is there a way to check/clean the injectors?

 

[adiffrentcity]

There are a couple different specialty tools available for testing injector operation, The one I'm familiar with is from mac tools (like $80 i believe) and is just a wand with an led in the handle that goes off when the injector pulses. You just stick the wand up against the injector in question and if its working (when it's supposed to - like with the engine running) the led will pulse like a strobe light and it beeps too. Also some larger shops may have injector cleaning machines, and also theres RC engineerings blueprint service. Never used them and dont know anyone who has but they advertise like a 2 day turnaround. Seriosly though check for crankwalk. One way a friend told me is to push and pull the crank pulley, If it moves in and out you need a motor. Also trouble shifting in left hand turns can be a sign. Hope you figure this out and its not that serious though. That would be a hard one for me to take, too.

 

[dsmdreamin]

regarding the above posting, not trying to step on any ones toes or anything but i read that a small amount of play at the crank pulley does not necessarily mean you have crank walk, not 100% sure but thats what i read, maybe this helps to avoid a freak out...

 

[Jordanbutter]

Ok well after extensive searching tear down and rebuild, it was a small vaccume hose that came off, bad spark plugs (I guess I need 7rs'), and a loose but not off I/C pipe. But it pulled a DSM on me and now that everything is fixed the clutch is being crappy again. Oh well thanks for all the help guys and thank God its not crankwalk!