R32 Gtr Will Not Boost Past 10 Psi

[Simonglos]

I have always had a problem with my car not boosting over 10psi the vehicle had already had the restrictor removed so I thought by replacing the factory solenoid with a boost controller it would get rid of the problem. I took the car for a drive and it was still the same so I removed both vacuum pipes from the boost controller to see if the vehicle would run more boost and still the same, I have replaced all the vacuum lines too and no success? Has anyone got any ideas it frustrating the hell out of me haha.

[scotty nm35]

Sounds like either your gauge is faulty, or you have a serious boost leak.

Are you trying to use the stock gauge?

Have you pressure tested the pipes?

[Simonglos]

Thanks for the reply. I'm running an aftermarket gauge, both the stock gauge and after market gauge aren't going up beyond 8 - 10 psi. I haven't pressure tested the system yet. But I thought If I would have a boost leak wouldn't I here a hissing noise? I was thinking about it last night if one of waste gates wasn't sealing would that cause it only to boost up to 8 - 10 psi or would it still boost a lot higher with no vacuum pipes connected?

[Ben C34]

No. You won't necessarily get a noise with a leak.

[mad082]

Are you sure you're working with the right vacuum lines? Try removing the vacuum lines that run to the wastegate (and block them) so you don't have a leak) and then go for a drive this should give you unlimited boost, so take it easy.

If after this you still only get 10psi then you have a few possible issues. Either faulty wastegate actuators, a large boost leak (but you should have other issues if it's leaking that much) or a blockage on either the intake or exhaust

[Simonglos]

Thanks for the replys. Today I couldn't find anywhere to buy the parts to make a boost leak tester, so I have ordered all things to make one of the internet so fingers crossed I will get them in the next few days.

I am running the two vacum Hoses which go to the stock boost solenoid, to the now new boost controller.

I have also replaced all the vacuum pipes which run to the turbos with new ones.

Thanks for that I will block of both the vacuum pipes and take it for a spin tomorrow and see if that makes any difference.

[Simonglos]

I also forgot to mention. The car also smells as if it's running very rich and the car seems to be burning a lot of fuel too, I'm not sure if this would be anything to do with the possible boost leak?

[Ben C34]

I also forgot to mention. The car also smells as if it's running very rich and the car seems to be burning a lot of fuel too, I'm not sure if this would be anything to do with the possible boost leak?

Yes it would. Air gets measured by the afms, so the ecu injects the right amount of fuel, but if the air doesn't make it into the engine because of a boost leak, the engine gets too much fuel and runs rich.

[Simonglos]

Ok i blocked of both vacum lines and still low low boost. I have done a boost leak test and it's holding Pressure. I plugged up a pressure tester to the actuators and they are opening well before 10 psi. So I'm leaning more towards the actuators / waste gates. I'm guessing the only real test now is to pull of the turbos and have an inspection.

[mad082]

If you've blocked the lines running to the actuators (ignore the boost controller) and it still won't boost past 10psi then there is almost definitely an issue with the wastegate actuators. Either they are getting pushed open by exhaust gases (they would have to totally shagged for this to happen, like opening at under about 3psi), or the wastegates aren't fully closing. There is also the chance of an intake blockage (such as in the intercooler). Try hooking a boost controller up to a vacuum line before the intercooler if there is one. See if it reads any different.

[Simonglos]

Thanks that's a great idea, I will try that tomorrow. On closer inspection I noticed the rear turbo has shit loads of oil inside the boost pipe just after the turbo so it could do with a new turbo anyway. So I will probably change the whole set up soon anyway.

[XKLABA]

Find a diagram of the boost control lines so you can understand how the system works, the factory wastegates on a R32 GTR are 10psi, blocking at the boost solenoid will give you 10psi

If you have a leak you will see plumes of black smoke out the back, easily visable in the rear view after a big hit of the throttle

I would look at the hose going to the map sensor next to the brake master, if the factory/nistune/PFC ECU doesn't get a signal from that then it shuts the boost solenoid and gives you 10psi

[Simonglos]

I have completely removed the boost solinode which runnes from the actuators to the the vacum pipe. I thought leaving the pipe of the actuator would leave it to constantly bleed of the vacum causing the wastegate not to open? The sensor to the left of the brake master cylinder is that for boost cut?

[XKLABA]

If you remove the line at the actuators then yeah they won't open and you will have unlimited boost

That sensor is for the gauge but the ECU uses it to confirm boost level to run/activate the solenoid, I ran upto 20psi on the stock computer with no boost cut just pumped out lots of black smoke

[r1ch1e]

How you going with the issue? I have the same problem at the moment only reaching 8psi, have done a boost leak test as per a DIY i read and found one leak fixed it and still only 8psi no exhaust leaks. Was running 1 bar previously with the factory boost solenoid removed, im probably going to pull the front bar off and check all hoses there and for blockages but im stumped!!

[t3harvinator]

I'm having the same problem too.

I was boosting a full bar then one day it just stopped and now i'm only getting .7

Any progress on this?