just brought my 97 uk turbo and the boost gauge is saying 0.5?this is my first scoob and turbo car so still learning but is this figure right?was told should be getting more than that,can it be adjusted?thanks

 

Hi, Should be close to 1 bar, (0.8-0.9) Check all pipework is correct and you have no splits/cracks, if all ok then clean boost control solenoid

 

It's bought, not brought

Seems like very low boost for a uk car. Might be a weak actuator.

 

If you are picking on people for a typo, you may consider a full stop for the above?

 

yeah i heard the same that if it boosts to only .5 bar then check that the black (read) connectors and green (test connectors) are not connected under the steering column.

worth a look i guess

 

0.5 bar means for whatever reason the purge solenoid isn't operating or purging enough pressure. So the wastegate is opening at it preset pressure (the wastegate is rated for 0.5bar...the purge solenoid is what allows for boost pressure higher than this).

First make sure the boost gauge is connected to the correct place (and accurate)...the intake manifold is the best (there is already a blanking plug next to the vacuum hose that connects to the factory dumpvalve ). If its connected to the wastegate pipework, it may give inaccurate readings due to the restrictor pill and operation of the purge solonoid (do not remove the restrictor pill ).

Second, make sure the wastgate solonoid is working (round thing that is bolted to the driver's side inner wheel arch). it should make a ticking/tapping noise when you gently rev the engine just above idle speed (1500ish rpm). It can also be heard operating with the ECU in test mode: If not, check electrical connections and ECU fault codes (look in the tech topics archive https://www.scoobynet.com/technical-...w-updated.html and download the relevant shop manual this will give you info how to check fault codes and what they mean ).

Third, check wastegate pipework. This is the small hoses going from the wastegate, to a T-piece which goes to the turbo outlet and also to the purge solenoid. With a larger pipe going from the solenoid to the air intake. Any kinks or splits should be fixed, and blockages checked and cleaned out.

Finally, make sure the restrictor pill is present and located in the correct place. On MY97 cars it should be inside the hose that is between the wastegate actuator and the Tee-piece connector. If its missing, the engine will struggle to reach target boost. If the car has had the cats removed, or had an aftermarket boost controller fitted, this may have been removed to prevent surging. Or it may have been inadvertently disregarded when replacing the factory hoses with aftermarket hoses (like Samco).

It should be noted that boost control on the MY97 difffers to that of the earlier year imprezas, so take note of this when reading information and make sure it refers to the correct year car.

 

Without being pedantic there is no blanking plug for a boost gauge on MY97 it has to be Tee'd in to an existing pipe.

 

0.5 bar of boost is also actuator pressure, had/have the same problem as mine if you want to check the solonoid is working and not sticking shut then put the car in a higher gear and ease down onto the accelerator and it should free up. Check the pipe work into the bottom of the airbox etc as well as if that falls out you will get the same problem.

Hope that helps a little.

 

what sort of vacum is normal to see?
recently i changed 1 of the small pipes to the T piece after it was split and over boosting now its only seeing 0.5 / 0.6 bar but some times -0.9 when i lift off..???

 

There is on the UK MY97 manifold; There is no need to Tee into anything:

Its on the manifold itself, right hand side by cylinder number 2 intake runner, just infront of the vacuum hose for the OE dump valve, blocked off with a rubber blanking plug:

 

Just looked high and low for that but its not there. They must be different on Imports.

 

thanks to everyone for the very good advice,hope to get some time to check these trhings out.

 

got mine sorted last night, didnt realise there was a restrictor in the pipe luckily i kept the old pipe and was able to cut it out, hope yours is a simple fix as well mate

 

got my boost sorted!eliminated the gauge and the solenoid.im still learning about my car and turbos so i will try my best,hear we go.there is a T-piece coming from my actuator and traced the pipe to the bottom of solenoid but found it was not connected but it was blanked off with a screw in the end.basically i removed the screw and pushed the pipe onto the bottom of the solenoid and straight away the car boosted to about 1 bar!it feels completely different when boosting so much more powerfull.my only question is why was this blanked?to me it makes no sense?the car still runs well and there are know lights showing on the dash?any input is welcome,and thanks for all the posts.

 

Dno mate, mine was the same when i first got it, BCS was bypassed so only had 0.5 bar, took me a while to suss it but same as, connected it all as should be and boosted fine with no probs, there are some strange people out there . Scoobs are a very steep learning curve Had mine 14 months now and just about understand the basics

 

i hear ya mate!spoke to the guy who owned the car and he said the car over boosted so his mechanic done the by-pass and he just left it that way.since all connected again ive had no probs but definately alot more smiles .from what i can gather 0.7-0.9 is where my car should be boosting so i am going to leave it connected as subaru intended.thanks again for all the advice.