dumping boost as soon as i hit 0.5bar

[Guest]

Hi im just wondering if someone can shed some light on my problem.
The past couple months i have found the car is not running as it should. i have an "R"reg legnum vr-4 type-s i think. my middle section of exhaust was shot and i assumed this was the problem untill i replaced that last week and the problem is still there.
The problem is when i accelerate the car goes fine until it hits 0.5bar boost then it seems to dump all boost out making a kind of droning noise and although the car still accelerates its not as it should be. i have taken maunal boost controller out the system and the same thing happens so i know its not my plubing and fitting causing this.
my friend says it sounds like the wastegate dumping all boost way too early. i am inclined to think i have a split in a pipe somewhere or a pipe come off somewhere but i have no idea where to start looking. when the boost controller was 1st fitted i did pop and split the hose that goes from the top rear of the engine to the brake sevrvo i think it is but replaced that. could anyone please help and tell me its not as bad as i am dreading. :'(

 

[Guest]

Do you still have the factory boost solenoid in there? But also, you could have a leaky BOV. The wastegates will vent boost from about 0.5 bar unless you have a Factory solenoid/MBC or EBC to keep them shut and build boost.

 

[Guest]

the engine is completely std. the only thing i have done is fit the boost controller and boos guage and a k&n replacemient panel filter. im no mechanic and have no idea where i would find the solenoid and wastegate. i have not fitted an aftermarket bov yet as not got the cash. not sure if this helps you at all. :'(

 

[Guest]

How did you have your MBC plumbed in? You should have come across the factory solenoid when you were installing that.

You say rear middle engine.. it wasn't like below was it? This is to the BOV.

Have a look through this too:

http://ozvr4.com/forums/showthread.php?t=908

EDIT: Ha, I see you are living in Helston. I use to live near Redruth when I was young, and my folks would drag me along to the Flora Dance.

 

[CLuTZ]

If this happened all of a sudden, perhaps you should check your cat converter for blockages

 

[pu-11-me]

Thats an odd issue.... Let me have a think about it and get back to you. I'm sure it'll be something simple.

Could be BOV.... But to dump all boost go and make a "droning" noise would lead me to believe it is something to do with piping.

 

[Scottie]

I would go with piping, but it would exactly dump all boost.

Have a look around at all your joins and clamps and make sure nothing it loose.

And as Clutz said, if your cat is buggered, it can restrict the engine enormously