Hi All,

Typical my first post is a cry for help

I have a WRX Wagon 94 and I have lost all positive boost. No smoke or nasty noise / smell or smoke

It I drive with high revs and take my foot off the accelerator then I can hear the dump valve, but it makes no dumping noise when I rev it when stationary.

I was told it could be the Brass (it looks like brass) boost valve ( ) on the drivers side under the bonnet. There is a way to check this is there not ?

Can I just remove it altogether and join the two pieces of pipe together or will it cause problems?

The car runs fine, but my Girl friends diesel is quick as I run out of steam at 2-3k rpm

Help Please.

It seem to run fine but a little noiser, and not the exhaust has started to blow at the centre bit - Oh joy.

At UR mercy.

Alloy (a newbie to Scoobies).

 

Is the check engine light on the dash lit up? If it is you probably have a problem that has put the ECU into limp home mode so it won't rev or boost.

 

I've found the early ones wont boost when stationary, I think this is due to the nature of the TMIC, if the car is still its more than likely going to be cooking under the bonnet so charge temp's will be right up so the ECU opens the wastegate to bring the boost right down until your moving.

 

i doubt very much you will make positive boost at a standstill. When moving the dynamics are different due to moving a mass along the road, giving the turbo time to spool.

its nothing to do with a TMIC or charge temps. the standard ECU does not compensate for charge temps anyway.

Ignore what its doing at standstill. whats it doing on the road? do you have a boost gauge fitted?

even if you are not making boost it will rev a lot further than that, but will obviously feel a bit flat. Are you sure your mate is not talking about the brass nozzle restrictor jet in the boost pipework. you cant see it its in a pipe between the Turbo and solenoid. If this is missing you will be well down on boost.

 

thanks for the feed back guys,

No lights are lighting up on the dash at all, and temp gauge reads normal ?

I was wondering whether I could remove the brass boost adjuster altogether (the one by the air filter) and join the two pipes together

Unsure what to do ? I don't think the Turbo's gone (God willing).

Alloy.

 

QUOTE"
i doubt very much you will make positive boost at a standstill. When moving the dynamics are different due to moving a mass along the road, giving the turbo time to spool.

its nothing to do with a TMIC or charge temps. the standard ECU does not compensate for charge temps anyway.

Ignore what its doing at standstill. whats it doing on the road? do you have a boost gauge fitted?

even if you are not making boost it will rev a lot further than that, but will obviously feel a bit flat. Are you sure your mate is not talking about the brass nozzle restrictor jet in the boost pipework. you cant see it its in a pipe between the Turbo and solenoid. If this is missing you will be well down on boost."

REPLY..
I can check to see if its missing after work (thanks), Its does drive fine but is flat after about 3kRPM but it will keep going further (thankfully) but at a slow pace. It can then dump (very quietly) if I've gone over 4k+ RPM in any gear.

Cheers.

 

You have mentioned a boost 'valve' on the drivers side and by the air filter (which is passenger side). which is it?

do you have a boost gauge fitted?
if so whats it doing when you are driving?
is it revving till 2/3 K or higher?

I *think* your problem may not be boost/turbo related but more concise info would be nice

edited to say seen your reply.

 

Hi,
It does have a boost gauge fitted, it goes upto Zero only now but can go very lightly over when the revs build up (when driving).

I can rev it all the way to 5k+ when driving, but I haven't tried to go higher since this occured.

The boost gauge functions exactly the same other than not going over Zero, it does still do the Negative boost movement.

My first Scooby, tell me I'm not paranoid about any sound it makes a the moment.

 

nice username

 

ok - check all the boost and turbo hoses for leaks and splits first then, including the one under the intercooler. check that all the vacuum pipes are on the manifold (i.e there are no little spigots without a pipe on them)

 

Very nice name mate wondered why it wouldn't let me use it

No knicking intended, I use it online for most things but am new to this forum so I kinda guessed it would have been similar to one used by someone

 

Will do thanks,

All the ones on top of the lump and by the Air Induction I've already checked, I'll climb down the back tonight.

Can I remove the adjustable boost brass bit anyway, it is on drivers side, samco has been used alot so I'm not sure if it is the one that "was" further down the back without checking. You can slightly turn a thread to adjust the boost - Not that I'm that brave

 

The "brass" thing your talking about sounds like a bleed valve to me? Basically a crude way of adjusting boost. If it is a bleed valve there is a very small hole in the back of them that vents off some pressure. If that hole has become blocked (it will only be a very small hole, not much more than a pin hole!) the the car wont make boost.

Is the car modded at all?

Stu

 

Hi,

Only subtle Mods I believe, I've not had it long so it needs so TLC I think. Creaking door, touch paint etc. Oh and a horrid rattle under low revs, but what looks like a tin case under the front - Yet to check.

I believe you are right about the location and type of vlave I was referring too mate, I will check it for a block. Fingers crossed that one of these suggestions (ideally that one ) will fix it.

Thanks Guys.

Mods I know of:
Exhaust
Air
ECU
98Ron Chip
WaterSpray
Suspension
Earthing Mod
Internal Fuel Pump
Strut braces front and back (pain)
Alloys
Some Sti parts used for these and bodywork/lights.
Oh and Steering wheel and Pedals
I am usure about Engine internals.
and a 2k Secret Mod (trust me you'd laugh)

 

The only reason I say that is most other turbo'ed cars I've driven will boost when rev'ed on the spot with an audiable hiss from the dump valve.

 

Sounds like you've got a bleed valve or manual boost control device fitted. As standard there is nothing 'brass' in the Scoob's engine bay that I can think of. I'd say take it off, join the two hoses, take it for a drive and see what happens.

BTW, no turbocharged car I've ever driven has ever made any boost to speak of at standstill, unless you rev them very high and very sharply. Maybe you could see a couple of psi max. Hence they also don't really trigger the dump valve, although sometimes you can get it going. When you're driving along, put your foot down above 3000 revs and you should see the boost rising quite clearly. You will feel it too. If everything is working that is.

 

May be totally irrelavent, but this happened to em on my well modified Sti v3, and the actuator rod from the turbo actuator (about 50mm round bolted onto the turbo) had come off the wastegate arm (the clip had sprung off).
Put it all back on and instant boost.
You won't show boost blipping the throttle.

Graham.

 

Do an ECU diagnostics shown HERE to see whether any codes have been stored. You say there is a chip fitted - what boost are you seeing?

Cheers

 

Is the brass thing you described just behind the air filter box (or where it would be if you have a induction kit fitted)? If so is there a red brown sensor on top and a brass looking cylinder underneath? If thats what you are describing its the wastegate control solenoid valve. I know what it is but dont know if it can cause underboost. Im just guessing but if its stuck on then the boost could be venting through it...Hope someone can answer this since im not sure how the wastegate really works to be honest.
I seem to remeber someone telling their wastgate was stuck closed and the car was over boosting.
was ages ago and my memory isnt so good thesedays ive been under a few hundred cars since then.

 

actuator must have come off the wastegate arm. Minimum pressure will be around 0.5 bar if the actuator is properly attached, regardless of what the boost control is doing.

Paul

 

Hi All,

Wow my heads is spinning - You guys know ur stuff

I checked the pin hole wasn't blocked on the Brass Manual Booster adjustor by the air induction and it was fine - no positive boost beyond .01 still though.

Could it be this ?
there is a pipe (from a T piece) that leads off before getting to this "Brass looking adjuster" that doesn't go to anything It looks to me as though it has come off a male adaptor that is after all the Air induction / MAS stuff.

When I lifted the Air filter (after market) up whilst still attached, I noticed this loose (little fingers sized in thickness) pipe that went under the induction part and towards the engine block. There is a black platic looking part that is part of the Air in system further along from the Filter that I believe this pipe should be fasten too. I have just had the spark plugs changed and was wondering it it had come loose

I hope it's simple I've just had to fit rear discs and pads, and I need to replace two front low profiles (gutted ) as tracking was slightly out and worn the inside.

MOT in May uh oh..... I love this car but boy it's hitting me all at once.

 

If they have fitted a manual bleed control this pipe may just be venting to atmos as it should.

As paul said you should always get a minimum of 0.5 BAR boost with a boost control pipework problem, either this or severe overboost.

Explanation, wastgate opens to bypass exhaust air to the turbo, open wastgate = lower boost, the wastgate actuator is powered by pressure, so more pressure = lower boost so if you had a leaking control pipe boost would go up, if your control system wasn't bleeding off air you would get 0.5 BAR which is the spring pressure in the actuator.

Check the wastgate actuator arm is still connected, that would be my bet, could even be the actuator jammed open, the turbo has to be fully bypassed to not make any boost, or else a knacked/siezed turbo, you say 0.01 BAR do you mean 0.1?

 

Ah yes it crept up to 0.1 when I took it up the M69 and increased the revs, it then gave a dump when I took the revs off.

On another note it can positive boost and dump when stationary and rev'd high, not that I am in a habit of doing this though.

Goes I'll need to take a spin around to API in southam to get the waste gate checked.

Unless anyone leaves in leicester or by warwick and can take a look or assist me ? I don't know this Engine much yet at all.

Cheers,

 

[QUOTE=AlloyUK]On another note it can positive boost and dump when stationary and rev'd high, not that I am in a habit of doing this though.
QUOTE]

That was before the no positive boost of course, All said and done I think a trip to API is called for

Thanks again Everyone, if only one can think of anything else I can try please let me know.

Cheers AlloyUK

 

just a thought but you seem to know your boost pressures. Is there a boost guage fitted? If there is a break or leak in this system i think it could cause a boost problem. Just a thought!
Where the boost guage connects to the pipe in the manifold. (its the middle one of 3 on the manifold below the intercooler) disconnect it and connect it straight through leaving out the guage! See if that helps. Of course you still have the wastegate actuator to check!
Your not the only one whos head is spinning. Compared to some on this forum i know nothing but i learn from every post i read. Ive worked on loads of cars as a hobby but only scoob turbos in the last 6 years and i havent seen every problem yet....THANK GOD.
Ill always try to help though!

 

Yep I've got a digital Booster Gauge/Turbo Timer.

I have seen the pipr which I think leads to it, it has a clear section of pipe too. The pipe goes to the dash board at the back of the turbo but its got dark before I could clearly see.

How do I remove the Chimney to the turbo (if you know what I mean) ? There is a nut on the top of it, well to the side. Is it this that releases the Chimney/Air funnel to the turbo?

Cheers.

 

I ran and hide when I read this link and saw the diagrams etc

I truely think I'll need help on this bit

I think it's a saturday pull apart.
Cheers

 

i was havin a few problems with my boost, so i had it cheaked out,in the end it was the boost control celunoid, it was boll***ed.

 

cant look at the turbo "chimney" just now its dark here too. PM me and send your e-mail i can send you a picture of where the boost guage is connected in the system. Since the guage is an electronic unit though i have to be honest and say i dont know what else is connected to it! More than that i dont know how it will affect the engine if you remove it! Is it the type of unit where you can alter the boost from inside the car? If it is i cant see why you have the manual boost control valve that some people seem to think you have? Any chance of some photos of the stuff you talked about. Like i say im no expert but i can usually identify whats in the pictures if it helps.

 

i have a turbo timer that also shows boost i think its just so the timer knows how long and how much boost youv bin using to work out how long to keep it running mine has a vacume type pipe connected to the inlet manifold it sounds the same sort of setup he,s on about