No High Boost

[big col]

Today my near-enough stock R33 decided it didn't want to hit high boost. I'm pretty sure it's the ECU restricting the turbo as the boost is fine and completely normal on low boost. But when I hit ~4500rpm when high boost would normally kick in it doesn't, just stays on low boost up to the limiter.

I've had some brown rusty crap in my radiator cap for a few months now before and after taking it to a radiator place (where they said they didn't think anything was rusted... wasn't exactly the most glamorous workshop though. The coolant doesn't have any rusty bits in it and seems completely normal apart from having a brown tinge (which the radiator place said was the colour of their coolant). Anyway, it hasn't overheated at all and the temp gauge is always below the half-way mark in it's usual spot.

I'm leaning towards either a rusty radiator (or engine block... that would suck) not cooling the car down well enough and the ecu restricting the turbo as a result.... but nothing has changed since the last 3+months and today. Or is it a sign that my turbo is on it's way out? I might unplug the battery and leave it like that overnight in an attempt to reset the ECU... but apart from that I'm at a loss to what the cause is. I've checked the oil/coolant level (do it regularly anyway) and even ripped out the air filter to check it was clean. I hate my car lately, giving me nothing but trouble

Any suggestions on the cause/what to do?

[maka]

Hey man.

I am guessing you are talking about an R33 gtst.

The stock boost controller is controlled by the ecu, and there could be a variety of things causing it not to go into high boost.

I personally couldnt be bothered trying to figure it out, and instead removed the standard boost controller, which gave me 7psi, all the way through the rev range.

have a look on the forums, in regards to disabling the standard boost controller. from memory it was something like shorting out the black wire to ground, which sends a signal back to the ecu. don't qoute me on that, but have a look on the forums, and you will find the post.

If your temp gauge sits half way or there abouts, your temperature should be ok. And i doubt that the temperature would affect the computer boosting.

And man, dont feel disheartened by this, it happens to all of us, i know how i felt when mine melted a piston, but now that she's all good again, i realise whyh i love it so much hehe.

You'll get it sorted.

Hope this helps.

Cheers maka.

[Magic]

It won't be the reason for losing boost, but In regards to the rusty radiator, It might 90% be radiator hose fitting into the plenum.

If you remove the radiator hose going into the engine I'm pretty sure you will find that the metal fitting the hose slots in will be all corroded away. I had the same problem with all that crap under teh radiator cap and got my dad to fabricate me a stainless steel hose fitting replacement.

Here's what my new one looks like..

But like I mentioned this won't be what's causing your boost problem. And I guess the radiator workshop would have checked what i explained so yeh...