RHB

re slow legacy .
i have since fitted a boost gauge and my boost changes every time i use the car . as i explained in my last post sometimes the car is ok n sometimes it seems to loose boost . tried it 3 times today and the first reading was 4 psi , then about 11 psi , then 8 psi , gauge is ok ,
any ideas thanx ROB

RHB

SOMEONE READ THIS POST , I KNOW ITS BORING AND I KNOW ITS A LEGACY NOT A IMPREZA , BUT HEY IF IT WASENT 4 THE LEGACY I DOUBT THE IMPREZA WOULD BE WAT IT IS TODAY, SO PLEASE HELP ANYONE

stiv62000

Gooday Mate,

Re: your problem.....When you say boost changes every time you take the car out., you must test under similar conditions...i.e. Let the engine warm up then drive till you find a long stretch of road and in 4th gear bring on the boost. Try this everytime you drive the car. If still boost levels are as erratic as b4 then something is wrong...Start by checking all vacumn hoses that are associated with the turbo, intercooler etc...Then i suggest you check your cars general condition...i.e. petrol filter, air filter, spark plugs, leads, fuel quality etc...If something here is amiss then the ECU could be limiting boost to prevent engine damage.
Also you need to be aware that your car will generally boost higher in the higher gears than the lower ones as the engine is under greater load in these gears and for longer. A common problem also seems to be the wastegate solenoid. This is T'ed into the hose running from the turbo outlet to the wastegate actuator diaphram. Follow this T'ed hose and it will lead you to the waste gate solenoid. This solenoid continuously pulses open and closed so as to regulate boost pressure seen by the turbo wastegate, thus controlling boost, and decreasing it at higher revs to prevent excess boost pressure from blowing up the engine! The only correct way of diagnosing this is to try swapping it with a known good one and then trying it out for a comparison. They can get clogged with oil thus preventing correct operation.

Good luck.

Yiangos

RHB

thanx m8
ive got all the pipes of and checking at the mo . one question if any one knows , one the right hand side of the inlet manifold there is a valve thing with a whit cap on it n 3 wires , a large pipe comes from it and goes to the air intake area , when i blow down this pipe ond move the valve side to side i can feel a restriction but it dose not shut the air off compleatly , wat is this and should it not shut compleatly under boost to stop boost going straight back to the air intake , hope this makes sence
thankx ROB


[This message has been edited by RHB (edited 03 September 2001).]

dfullerton

Sounds like your turbo is on the way out mate

RHB

HOPE NOT , SEEMS OK , NO OIL IN IT , SPINS OK, DONT SMOKE , THINK MAYBE THIS VALVE THINK IS LETTING PRESSURE THROUGH BUT I DONT EVEN KNOW WAT IT IS SO I COULD BE WAY OFF

Richiehash

try putting the boost gauge in the line between the wastgate actuator(turbo) and the boost control solenoid (the valve thing) this will give you some indication of the valve output (i think it should show a max of 7 psi, bob or a real tech head may confirm this pressure) any major fluctuations in pressure should point to a wobbly boost solenoid as even a well worn turbo should manage 7 psi.
another possibility could be a us wastegate
to test this again use a boost gauge in the same line but this time use an old tyre valve cut to fit the pipe. inflate using a bike pump or something similar and study the watsegate movement against pressure fully open is 7 psi (0.5 bar) i think
how full is the oil level as there are known issues with full sumps and solenoid valves.
hope this helps
(one very mashed) richie
ps legacys rock big time the next cult scoob now prezas are everywhere


[This message has been edited by Richiehash (edited 02 September 2001).]

RHB

I THINK IM CONFUSING EVERY BODY NOW , I THOUGHT THE WAISTGAIT SOLENOID WAS ON THE L/H STRUT TOWER (LOOKING FROM FRONT OF CAR)
WITH 3 PIPES ONIT , CHECKED THAT , THE VALVE THING IM ONABOUT IS ON THE R/H SIDE OF INLET MANIFOLD THINK ITS MORE OF A GATE THAT OPENS AND CLOSES RATHER THAN A VALVE THING AND ITS ELECTRICALY OPPERATED., IM ONLY SUSPECTING THIS COS IT DOSENT SEEM TO CLOSE PROPERLY AND MAYBE LETTING PRESSURE THROUGH

RHB

tiz ok i know what it is now , think itsa a
idle speed controller or somethink like that
still like to know if you should be able to blow through it at all when its closed

[This message has been edited by RHB (edited 03 September 2001).]