Long story short my brother acquired a 13' r58 n14 jcw.
it would go into limp for low boost threshold and i verified the jcw turbo had a bad wastegate, so i replaced the turbo with a 48mm , all new boost tubing and intercooler.
I unplugged the vacuum lines from the boost solenoid and the vacuum tank/line held vacuum perfectly and thr wastegate line also held vacuum just fine and pulled the wastegate shut.
i smoke tested it roo by pumping in smoke through hotside intercooler hose through the ic and throughthrough manifold and NOTHING. It steady hold -13hg at idle but will only make 1psi. I also made sure I could only suck and not blow through the pcv.
new plugs , coils , turbo , gaskets , hoses and intercooler.
Wtf.....
there are NO cel codes , I've checked with numerous scanners and even a cobb n14 amd nothing.
could it be a bad boost solenoid not functioning ??
I'm at a loss here guys , PLEASE help me HELP my brother.
He hasn't been able to enjoy the car YET.

 

Is the high pressure fuel pump failing?

 

I don't believe so , no misfire codes or anything related BUT when I start up the car , wastegate DOESN'T move and doesn't move as I give it throttle..
failed boost solenoid ?
Car has 80k miles only..

 

The information you posted seems to point to a faulty boost solenoid/pressure converter. But are you testing for wastegate movement by revving the engine with the car parked?

There's a recent tuned N14 thread where a boost issue was suspected. The problem turned out to be a bad ignition coil.

 

I wouldn’t expect the wastegate to close if the car isn’t moving, only under engine load. The boost solenoid could be failed…

 

Exactly. And how would you test whether the wastegate closes while driving?

I would take a step back and ask whether this is a boost issue or something else?

 

Does it still go into limp mode after replacing all those parts?

 

car has new ignition coils and plugs..
doesn't wastegate move when the car is 1st started ? I was told to watch for that.
I do have a new solenoid coming tomorrow anf hoong its the issue. I had a similar issue on my last r58 n14 but it was low boost but that was too caused by a faulty solenoid.

 

no it doesn't. NO cel , no limp mode..

 

Here's what I just read:
(1) When engine is OFF, wastegate should be OPEN by default.
(2) When engine is idling, wastegate should be closed.
(3) When engine is idling and then revved, wastegate should remain closed.
What is the state of your wastegate under these three conditions?

Have you verified that the two vacuum hoses attached to the boost solenoid have not been swapped?
Is the DME tuned or stock?

 

yea , they can't be I thought because the 2x ports are different sizes on the boost selenoid so if they were id think that's be pretty obvious.
my wastegate is open 100% at startup and it doesnt move a smidgen.
I can unplug the vacuum line to it , suck through it and the wastegate smoothly shuts and it holds shut.
I also tested the lines to and from the vacuum tank from the vacuum pump to tank , tank to solenoid and solenoid to wastegate, no leaks.
boost tubes are also sealed tight. I'm 99.9% sure it's not a vacuum leak or mechanical problem..
either dme is not commanding the boost solenoid to activate or its just dead.
I maybe thought it was still in limp mode but without any mil's illuminated but i did reset it via inpa..
once my body cooperates i will see if the solenoid is even pulling vacuum because I don't think it is.

 

You'll know soon enough whether the boost solenoid is bad.
Have you also considered that the larger turbo and intercooler could cause this problem? The much higher air flow likely substantially conflicts with the DME's expectations.

 

Ok , sooo is it missing a fuse here for the dme ??? Next to the 40am I'm pointing at ???
because I swear there should be one there

 

I did just verify the vacuum tank is ok. I checked BOTH nipples on it and hooked up lines to it to test its vacuum amd it holds vacuum and pressure just fine , alone with all the corresponding lines.. I'm still waiting on selenoid but I don't think thats the issue becomes I applied 12v to the selenoid amd could hear it activating..whats odd is too I unplugged the vacuum pump and heard no hissing and it is a new pump.
new selenoid will be here soon to try.

 

I'm so retarded. I hear boost Now.. just gotta button it up.
lol that was covering the vacuum pump port. Being colorblind is a ****. I can set my black phone on a black countertop and loose it.

 

lol, looks like the packaging nipple cover. Should be good to go now!

 

Nice

 

FL7 is an empty slot

 

unfortunately not..
Now once full throttle and I hit anything above 5k rpm , power reduction mode and 2x cel for i believe is a bunk mafs..
so now I need to get a mafs..
Lol I See why i hated n14s.m

 

Those two codes are almost surely caused by the oversized turbo and intercooler, not by a bad MAF sensor.

 

I’d be willing to believe it’s the bigger turbo also…

 

Time for a stage 3 tune or to return turbo and intercooler to stock.

 

The intercooler is fine. Bigger intercoolers don’t really change volume of airflow that much. The bigger turbo, on the other hand, will pull much more air than the DME expects.

 

Not sure what the P2B5B code is… Don’t you have a reader to pull the Mini DTCs instead of using that to pull the generic OBD codes?

 

The larger intercooler cools the air much more efficiently than the stock intercooler. This will continue to create a mismatch between DME expectations and actual air flow.

The DME apparently is already tuned as implied by the mention of Cobb.