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Hey all,

I had to go on a bit of a long drive today and when driving for a bit over an hour, my GTR started to loose boost.

I only have the stock gauge (restrictor out) and it normally goes above the 7 on WOT (wide open throttle).

After driving for a bit over an hour and while accelerating i felt it just die down, and now the gauge would not go above the upper middle marker (the bit between 0 and 7).

Sounds like a very similar/same problem to this bloke here; http://www.skylinesaustralia.com/forums/topic/102476-r32-gtr-loss-of-boost/

But alas, no resolution on that thread.

Anybody know whats going on?

I am leaning towards the stock rubber piping gets hot and starts to restrict airflow to the motor, the ecu goes wtf is going on and puts me in "safe/retard" mode, preventing me from boosting 100%. Least thats one of my theories...

Hey there,

It won't be any of the piping you have there - I have the same piping and have never had issues with it. Besides, something like that would be a major fault and would have seen recalls :D

However, here are some things it could be:

- If you're running pod filters without a partition you could be sucking in too much hot air (I have those issues in summer with a bit of power loss)

- Your AFMs may be giving up slowly and could become very noticeable when they get hot as with a lot of electronic gear, so you could test these.

- You may have a sloppy or broken actuator on one of your turbos. If it the actuator goes or gets too soft then it's an INSTANT power loss and you will know about it. You can easily test these by reaching down there and pulling on the rod...or test with a pump/gauge etc

- You could also be having fueling issues...ie dying pump, old fuel filter or dirty injectors. Do you have a service history to share?

- You may also want to check ALL your vacuum lines for leaks....and while you're at it, all your pipework hoseclamps.

When did all this start to happen? Has it always been like this or did it happen for the first time the other day?

Hmmm, good point about the piping tom!

I am running pods, HKS ones to be precise.

I only noticed this today on my long drive, Drove for about an hour a half happened pretty early on , maybe about 30-40 minutes into the drive. (Nice open long straight country roads). Never has happened prior, then again never really had a nice long open country road to drive on before.

On the way back it was fine, till the last 15-20 minutes of the drive. So it was ok for an hour. During that time it happened while i was in 5th on boost, then i just saw the gauge drop and felt the loss of power.

On the note of black smoke - Yes, it normally blows a bit of strange looking smoke (kinda blackish) if i have been babying it then decide to go WOT. I figured this was normal though. The idle doesn't seem rough, cold or hot. Idles at 1,000rpm when warm, I also check my oil often and it hasn't used a drop. Also on stock ECU, hasn't been tuned.

Has HKS Pods, Ganador exhaust, hiflow car. Stock everything else.

Does it make whistling sound while doing it? If so, read below.

Check all the intercooler hose clamps, it might not have good clamping force it used to be. Replace all the clamps while you're at it for good measure.

And look for 'cooler piping behind the front bumper (especially LHS) cos they pop out often.

If a popt intercooler piping you should feel it rough idle i have had the same issue on a few cars but it would be quiet noticeable

I would check the turbo for play and as stated above make sure all the i/c piping is on secure

Thanks for all the tips fellas,

But if a turbo had shit itself, or a pipe had fallen off.

Wouldn't it be loss of boost all the time?

As it drives fine just after X amount of time driving it will stop going full boost.

Something is getting hot is my guess. Something electronic.

this is my vote as well

did it come good after being parked ?

loose conection maybe ??

i know i had issue with AFM plugs

is you blow off valve plumb back ??

air lock in intercooler /pipeing maybe??

Edited by vorse

After getting to my destination and leaving it parked for a few hours, It was fine, but then happened again on the way home.

Drove it today on my daily commute and it was fine, (to be fair my daily commute is short as hell) so i got no idea now. I am leaning more towards something failing when it gets heated, due to the fact if it was a pipe that was constantly loose, It should be consistent loss of boost.

Do GTR's have a "safe" tune the stock ecu map's too during certain situations? Such as if the rubber pipes were causing a kink, ecu thought wtf too rich and just invoked a safe tune?

^ yep.

Either that or a VAC line or similar is getting a bit hot and loose.

It won't be factory piping - I drove to Sydney with my GTR, twice. It was fine with 360rwkw, i can assure you of that ;)

You'd notice the car playing up if air was escaping due to AFM reading the air and the motor then not seeing it

But if a turbo had shit itself, or a pipe had fallen off. Wouldn't it be loss of boost all the time?

Correct. It wont be a pipe off or broken turbo. If that happens you have vacuum as normal, but never makes any boost.

Do GTR's have a "safe" tune the stock ecu map's too during certain situations? Such as if the rubber pipes were causing a kink, ecu thought wtf too rich and just invoked a safe tune?

Ive seen a 33gtr go into limp mode already due to high temps and running on 95, and all the ecu did was pull about 8* timing.....no change in boost or anything, but you could definitely feel the loss in power. This car didnt have the stock solenoid tho ...

Interested to see where this goes.. I had the same problem in my old gtr when driving from Brisbane to

Sydney.. Was about 100km out from Sydney and the car lost power and wouldn't boost properly. After a stop at the servo for 30min the problem went away never to happen again

Edited by GTR_JOEY

Similar thing happened to my wifes WRX all of a sudden was only running actuator pressure a week later back to the normal 12psi. Suspect the stock solinoid had a fault give yours a good clean out and then send 12v through it an make sure its working

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