Jump to content
SAU Community

Recommended Posts

Hey guys,

I d like to ask for advice... My newly bought skyline running perfectly on 7 psi but if i raise the boost to 10 psi it cuts out at 6000 rpm and i just cannot tune it out.... when the engine is hot its getting worse (5500rpm)... I connected a  smoke machine to check for leaks...I marked the blocked pipes with red X....the smoke is immediately (at low pressure) coming out from the crankcase and from the inlet manifold...

20171216_140137.thumb.jpg.b0cb2b297a41de7fa8a06aa2f0b9dde8.jpg

 

It just doesn`t make sense to me how can it smokes from the engine when everything is blocked... Is my turbo leaking through the bearing housing back to exhaust and through the open valves comes out at the inlet? Or is it normal? Any idea? I m kind of getting hopeless for now maybe just i m the dumb and cannot tune it out (datalogit power fc, Z32 maf)... pls don`t spare me everything helps, have a good one

Link to comment
https://www.sau.com.au/forums/topic/473789-rb25det-turbo-leak/
Share on other sites

Sorry about that i just didnt make a picture how the smoke was connected so i tried to improvise.... I connected the smoke to the inlet before the turbo (blue arrows).... I blocked the inlet from the intercooler so it should hold the pressure... but it s not holding any pressure since the smoke is coming out from the inlet manifold and the crankcase where the red arrows are with the ???.... And that s what i m asking if it s normal?

20171216_140137.jpg

I assume you have the breather pipe and bov plumb back pipe blocked that comes out of your stock intake pipe. Try blocking it closer to the turbo, for example, block it before it enters the intercooler.

or, enter smoke right after the turbo and block off the same as your picture^^

NEO25T: I think I m gonna try it on the weekend

Kinkstaah: yeah it is an Apexi Power FC with Datalogit I have a log file what is happening...

the AFR at the cut point is about 10.75 (so it s not too rich or too lean) I ve tried to adjust the airflow data....change the whole MAF...still the same... after the car is hot the cut is happening at 4320 mV or less... It is a Garrett GT28 turbo, 7psi wastegate with a turbosmart tee set to 10psi

boostcut.png.c36ca76b7d6fa524fa18e7c69d94fdd0.png

RB25detonator: yeah i ve done it too leaking out on the same places (crankcase and inlet)

Out of curiosity how did you block the pipes?

The easiest way i found was to bag the end of the pipe with black plastic and clamp it back together. 

What spark plugs are in it, thinking back mine cut out like a rev limit at 6k when i got it. The plugs in it were nasty and new ones fixed it up

On 4/18/2018 at 8:50 PM, Ibanex said:

yeah I used rubber gloves with clamp for alloy inlet and for the hose used degreaser can and clamped it  for smaller pipes just bolt and clamp.

I thought about the plugs too and I changed them last week for NGK BCPR7ES... they should be fine right?

They should be OK but Iridiums better. If you still have stock coils are your plugs gapped down to ).8mm?

the only thing is that it really doesnt feel like a missfire...it just cuts out all together...  these plugs came already gapped to 0.8mm and the coilpacks (blue splitfires) should not be older than 2 years... so not too much left just keep on experimenting and spending some money...

  • 2 weeks later...

If that is a full WOT pull, from the entirety of the video (i.e not backing off) and boost is dropping into massive vaccum like that, I'd be putting my money on that stock silicon hose sucking shut.


Especially given you said it runs fine on stock boost...

  • Like 1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Brooooo Please send ABS control unit schematic Please! R33 gts25t ABS (Its two plug ecu, black and white) wire colors possible? [email protected]
    • Don't even try to run it on the stock ECU if you're going to have the boost controller bring boost above ~10 psi. I've already told you that. If you use the Nistune ECU, you will need to CAREFULLY read the available documentation for Neo tuning, and read some threads on the Nistune forums, to discover the various things you have to do to prevent the ECU from going bananas when the boost is too high. The is a table associated with th boost sensor that must be modified to prevent it from shitting the bed. This is just one of the things that you will need to do to the tune in Nistune, because the Neo turbo ECU will be expecting to see a number of things (such as the TCS) that are not there, and you have to block the DTCs on those. It is totally not surprising to me that you are having the problems that you are, but the solutions to these problems have been known for >15 years. So just get it done.
    • Hi. Sry iam not a mechanic and iam not at the car atm so i dont know 100% but they told they measure those and even try to change those. AFM they have two. Coils are new a they have my old one too. Plugs too. ECU...we have 25 NEO stock and Nistune 25 NEO.   But i dont know if any one those could be the problem and why/if/what can cause this, Only thing they did not check is fuel...but that walbro 255 is new(like 1,5 years)... That fuel pressure gauge idk...but i let them know Any suggestions?   EDIT: how can they know if it is like you say he ECU pull power when it reaches a specific boost level that is too high? Tha car has boost controler
    • Can you clarify what you mean by boost cut, do you mean it misfires both when under load (driving) and when stationary and out of gear? Or does the ECU pull power when it reaches a specific boost level that is too high (boost control issue)? Does it occur at idle with no throttle? When you say "the ECU is OK", what ECU is it and why do you think it is OK? Have you used the NEO ECU, and if so do you have a MAP sensor attached? Same for the AFM, why do you think it is OK? Do you have any way to put a fuel pressure gauge on it (even just a mechanical one between the fuel filter and fuel rail)?
×
×
  • Create New...