Boost Problems

[hotchicken]

Hi all,

I seem to have a boost problem which I need some ideas on.

I recently had an under the bonnet boost valve fitted to the pipe which comes of the actuator. The car appeared to be pinking so I thought it best to get a boost gauge to see what boost I was running, however once fitted the boost was at 17 psi which under standard set up I belive this to be far to high. so I turned the boost valve down which did not reduce the boost at all. I then removed the boost valve and returned the car to standard, again this had no effect on the reading on the gauge. I have been told the boost controler which is ment to be the unit at the other end of the pipe coming from the actuator is faulty.

What do you guys and girls think?

Cheeers

Rich.

[scoobysteve]

From my calculations your running at 1.17 bar. standard is around .8 bar which is what mine is running at. it depends what mods you've done to what boost your putting out. but if its all standard then the boost controller might be a start. the maf sensor could be at fault too as they can change the boost if there faulty and cause the pinking.

[hotchicken]

ok. The car has a Blitz dump valve and a de cated exhaust system apart from that the engine is as he came out of the box.

[scoobysteve]

The de-cat can give a bit more boost as theres not so much back pressure, im not sure if it'll give as much as that though. May just need a rolling road tune up to get rid of the pinking. i personally would go for a maf sensor anyway to be on the safe side as there known to go tits up and can damage the engine. But there might be someone else out there that knows a bit more and know of the problem so best to hang on for a bit.

[The M@trix]

what age is the car? mine will not run 17 PSI as the Injectors top out at 15PSI.


at 17 PSI with a STD ECU you will be getting Fuel Cut.

Not a Pinking.

[bob]

Fuel cut is about 14.5 so if you do not have FCD I don't see how you can get to 17 unless its been remapped? You sure you are undoing the boost controller and not tightening it?

[The M@trix]

the std one should not be producing anywhere near 17. the Manual Controller, needs to be unscrewed, making it longer, reducing the tension on the Spring, Screwing it in the Way making it shorter increases spring tension and in turn increases boost.

I would unscrew the Manual controller quite a bit, and then try it again.

They are a very simple yet reliable and Effective Design. ScoobyMagazine. Actually Say This Should Be the First Mod On Any Subaru Turbo.

it is unlikely that it will be faulty. the one on the wing if faulty i would have assumed should put the Engine management light on.

Is the Boost Gauge Accurate? I previously Bought a Digital one and found on the Rolling road it was well out. as Interpro attatched a boost gauge on their setup.

Derek

[bob]

Great minds ay Derek...:hysterical:

Have you removed the restrictor? is this still fitted and blocking?

[The M@trix]

Yes great minds indeed.

good point bob. their are on some guages a removable restrictor, maked the hole where the air goes into the boost guage much smaller.

[bob]

Yes great minds indeed.

good point bob. their are on some guages a removable restrictor, maked the hole where the air goes into the boost guage much smaller.

The restrictor in the boost gauge line is to stop the air lines vibrating. You can get a terible vibrating sound from the air lines sound like a gearbox whine. Had this on last scoob and had to go digital to stop it. I was thinking of the brass restrictor in the line by the boost solenoid where the boost controller was fitted. As then you would have two restrictors one brass one and one boost controller. :wink:

[hotchicken]

Hi

Thanks for all your advise but the car was pinking before I fitted the boost gauge and I have now removed the after market boost valve and returned the car to standard but it still pinks. The garage who look after the more complicated problems I occationaly get said it will be the standard boost controler which is attached to the pipe that comes of the actuator. As I am led to belive this sends information to the ecu so if it is knakered then it will be telling the ecu incorrect information. As they are about £70 for a new one I am trying to see if it could be anything else before I go down this route.

Thanks again all.

[hotchicken]

Ok I will give this a try tomz and see if it helps and let you know either way

Thanks::party0044:

[hotchicken]

Hi again,

I have take the boost controler of and given it a good clean and blast out with cleaner as suggested but it makes no difference/

Cheers

Rich.

[Olly P]

Sounds to me like you have an air leak.
It probably happened when the boost controller was originally fitted.
Which would explain why adjusting the valve or taking it off made no difference.
Get someone to rev the car up while you have a feel around the pipework connected to the boost controller, actuator and turbo, and see if there are any leaks.
There is also a chance the pipework may be the wrong way round, its easily done.
A pic of the area would help.:smile:

[The Daddy]

is it a full decat.....downpipe center and back box????

[The Daddy]

if you have the decat down pipe this could be allowing your turbo to over boost as there is minimal backpreassure...this is a common problem and a good rolloing road can sort this for you.....

the plumming to your solonoid valve should be from turbo inlet housing to top of solonoid, center solonoid hose outlet to actuator and bottom out let to air intake or atmosphere..........i dont think the earlier models had an inline restrictor as the boost solonoid does this......

[The Daddy]

also the colder the ambient temp is the densor the air and more chance of boost cut....