allon

My wastegate valve is not responding well as I'm getting only 0.5 bar.
The wg solenoid & pipes & turbo are all ok so the wastgate itself must be at fault.
Has anyone experienced such a problem?
Does the wastegate need to be replaced or can it be repaired/serviced/oiled ?
Would greatly appreciate your opinions.

mike ed

If you are doing 0.5bar that means that your wasgate perhaps in not closing well the 'buterfly' under normal conditions.
Has anyone else experienced this ?

[Edited by mike ed - 8/22/2002 8:11:55 AM]

allon

Yes, this is the case.
I heard that the diaphragm can be at fault or buildup of coke on the 'butterfly' window ?
Anyone ?

[Edited by allon - 8/22/2002 8:20:30 AM]

dowser

.5 bar probably means your solenoid is not bleeding air *away* from the wastegate, so your boost is controlled by the wastegate spring pressure.

What MY car?

Richard

allon

Hi richard, It's an MY98.
It's not the solenoid since it was replaced and same prob.
The selonoid is controlled via the ECU which gets a reading from the map sensor.
I think it's highly unlikly that the map or ECU are at fault or isn't it?
Did anyone else experience such a problem ???




[Edited by allon - 8/22/2002 1:51:21 PM]

Chod

I had exactly the same problem as you (MY97). I also checked all the pipes and my Subaru dealer replaced the Solenoid, still had the same problem. Problem was solved when I put my dawes device on. Am now getting whatever boost I set it to, so thought that this means that the wastegate was probably ok?

Would still like to know what is causing this so I can put it back to standard when/if I sell her for a newer one.

My next thing to try would be to replace the pipes and restrictors as when these are taken out of the equation, everything seems ok.

Terry

PS Select Monitor showed no error codes.

silver:scooby

Sounds like the ecu has put the car in "safe mode" only 0.5bar of boost as its seeing somting it does not like. Fitting the dawes device will give you your boost back but does not slove the problem. I had a the same problem on my my99 car 0.5bar of boost which turned out to be a faulty maf senser under reading on boost causing very lean mixture and detting, so the ecu put the car in to limp home mode. DO NOT put a dawes device on untill you sort the problem and get the car running on its oe boost solenoid, or it could be very costly running 16 psi on a very lean mixture ie new engine.

[Edited by silver:scooby - 8/22/2002 9:42:38 AM]

Stephen Cole

If you want to check if the wastegate is leaking or stuck open, one way would be as follows

Take the pipe off the wastegate and try a gentle run in that state
(wastegate at zero pressure and should be closed all the time)
Drive very gently to a suitable stretch of road and to get engine warned up, then accelerate moderately briskly and check that it boosts to well over 0.5bar and up to the expected 1 bar (or whatever)
Don't push it too hard as you will overboost
(unless you want to try it!)
an even then it won't be disasterous as the overboost cut out will occur.

Assuming that checks out ok, you need to somehow monitor what pressure the wastegate is seeing
ie wire up the boost gauge, or another boost gause, to the wastegate pipe, and see what pressures it is showing
(wastegate should start to open at 7psi. Not sure if it opens further at greater than 7psi or if it is effectively fully open at just over 7psi)

Good luck
Stephen

dowser

...assuming you still have a fuel cut...be careful

Richard

allon

Thanks Stephen, The pipe to the wastegate was disconected and the boost level was 1+ bar at the engine.
When the pipe was re-connected the boost level dropped to 0.5.



[Edited by allon - 8/22/2002 1:58:59 PM]

dowser

So your solenoid is not functioning.

Richard

allon

The solenoid itself is ok but that doesn't mean it's getting the correct signals from the ECU if at all.

Did anyone else experience ECU problems or map sensor problems?

How likly is it that the wastegate itself is at fault ? !



[Edited by allon - 8/22/2002 5:15:30 PM]

Chod

I understand what you are saying about not putting the dawes on until the problem is sorted, but surely if the ECU was putting the engine into limp mode, then an error code would show from somewhere? Did you get a MAF failure error, I am not getting anything, and the engine is running great with the dawes on.

Terry

allon

Let me guess, the DAWES bypasses the wg solenoid thus bypassing the ECU & Map sensor.
If this is the case you shouldn't worry to much.
However if your wastegate is not functioning well this could be a problem.

[Edited by allon - 8/22/2002 5:14:12 PM]

mike ed

Maybe you should reset the ECU (anyone knows how ? )

silver:scooby

There are two types of maf faults one is sudden engine check light poor running, or the worst to find is where the maf gives lower and lower voltage no engine check light.
when my car started to play up the boost would be ok for days then cut to 6psi switch engine of go back all ok for another 2-3 days. then i would only get full boost back after ecu reset but only for hours untill finally only 6psi all the time even after ecu reset
The dealer had it for a full day no fault codes and unable to find the cause. I got the car back had had a look my self fitted a afr meter which showed lean running, then tested o2 sensor and maf voltage which turned out to be low orderd new maf fitted all back to normal.

Your car maybe running great with the dawes but could be detting its nuts off untill one day it may let go, have you got a dawes afr fitted.

Chod

No, haven't got an AFR fitted. I have got one, but have not got round to fitting it yet. I think I will take off the dawes this weekend and order a new MAF filter. I do have a K&N filter fitted, so may also take this off when I fit the new MAF. I understand that I can order just the filter part of the MAF now, not the whole unit, is this true?

So, can the car be detting without you realising it? What are the tell tale signs?

Sorry for hi-jacking this thread, but it may also help others with the same probs.

Thanks for the help

Terry

silver:scooby

Hi terry Yes you can buy just the maf sensor some dealers are very funny about selling you just the sensor. There product code Is
22794AA010PE AND IT IS A METER CP-AIR FLOW thats of the box it come in. Oh just looked at your first reply your car is a my97 that part no is for the hot film type my99 i think your is the hot wire type put thread to ask for the hot wire part no.

I went down the same road as you fitted a dawes device and thought i had cracked it, it was not untill i fitted the afr i new there was somthing still wrong. the car had a ramair panel fiter in when the maf went, i fitted a k&n induction kit with the new maf. I think that K&N are one of best for not killing the maf so leave it on. Yes you can be detting with out you knowing the only way to find out is with a knock link,select monitor,delta dish or rolling road ,I dont think there is any tell tale signes,
Hope you find the problem.

Daz


[Edited by silver:scooby - 8/23/2002 2:05:55 PM]

mike ed

So back to the ECU business...
What can cause the ECU to enter safe mode ???

Chod

Just put my car back to standard (removed dawes and K&N) still only getting 0.5 bar. I did notice that there was a fair bit of grease/oil in the bottom of the air box. This to me would mean that at some point in its life it has been overfilled with oil and it has sucked through the MAF the wrong way. Is this possible and would this knacker my MAF without giving me an error code?

Terry

PS The car is soooooo slow again now....gotta get this fixed!

silver:scooby

Yes it can as in my other reply if the maf is under reading on boost and getting a lean mixture and detting the ecu changes the ignition and fueling to try and get the detting under control if that does not work the ecu gives up and finally shuts the boost down (safe mode). Its a bit more involed than that but you get the idear if you want it in full ask John Banks as he is S*** HOT on ecu and maps and how they work.

It stores all this info on it temp memory untill you remove it by select monitor or by removing the power to the ecu for a an hour or so. This was the only way i could get full boost back on my car untill i fitted the new maf i tried the black and green conectors under the dash but no joy i think it only removes fault codes, im sure i will get shot down in flames for saying that, thats only from findings on my car so dont be to hard lol

just been thinking is the pipe clear from the boost solenoid to turbo inake if it ant you cant bleed air away thus only getting wg pressure 0.5 bar.



[Edited by silver:scooby - 8/25/2002 9:38:11 PM]

Bob Rawle

What actually happens is that if the ecu see's knock retard of more than a certain amount for more than a defined time period then it shuts the boost down, its interesting to see that the Sti's and P1's are set to respond more quickly than the UK/Eurospec cars, since they are "allowed" to use 95 ron fuel then its expected I think.

I have now remapped my car to not react, it is a pain in the neck when you are developing maps !!

Bob

mike ed

So ECU enters safe mode only if there are maf or fuel grade problems?
Are there other possibilities ?
Also how do you remap the memory, I'm not clear on that.

[Edited by mike ed - 8/27/2002 7:48:29 AM]

allon

This is a good point Mike. Does anyone know if apart from Maf sensor faliure there are other reasons for ECU safe mode engagment?

Chod

New MAF for a MY97 £200. Cannot buy the sensor only on this model. Didn't want to spend £200 incase this is not the problem (no error codes to indicate this). I have booked it into TSL next Wednesday to get it sorted. I will let you know how I get on.

Terry

john banks

Bob is referring to remapping the boost, fuelling and timing on a 99/00 car.

http://www.ravensblade-impreza.com/m...agnosisegi.pdf is a handy pdf file - give it time on a slow connection - that tells you the various sensor faults, their investigation, and their consequences - ie which ones cause safe mode.

Chod

Well, got my car booked in at TSL on Wednesday, but thought I would take off all of the turbo pipes and give them a good clean. Took off the one that goes to the bottom of the Boost Solenoid and noticed a restrictor in it. DIdn't know that they were supposed to have one of these, so I gently pushed it out and found it to be a peice of plastic with a hole through the middle (the holes at each end of the plastic were not even the same size!

Took this out, re-assembled and got my boost back!! So, car running great again, and saved myself some potentially big bills.

I've had the car for about 4 months, and this must have been in when I bought it. Why?

I also had a new boost solenoid fitted by a Subaru dealer, and when they found that it didn't solve the problem, they were not interested in trying to find out what the problem may be!! (Thanks Oaken!). Thought that they may check the pipes but obviously couldn't be bothered!!

Anyway, don't care, got my boost back!!

Terry

Jaay

Hmm must have a look for this, as ive been reading all the above posts with baited breath and crossed fingers in the hope that the holy grail of information would come to light.

The conclusion is, if I dont find this restricter and I dont remember seeing one when I was cleaning pipes then I have to fork out £200 for new MAF sensor.
Antone know the part number for the 'Wire' one from a 96 STI ???

tweenierob

Hold on a minute!!!!
Take of the bottom pipe from your solenoid and check that the restrictor in the pipe is not blocked, this pipe is used for bleeding off air so that the solenoid can control the boost level...
If it is blocked then the solenoid cannot bleed off any air and will not be able to raise boost..
Basically, take off the bottom pipe and give it a good clean out with carb/brake cleaner.....
Rob.
just to add.. the restrictor is a small brass restrictor that sits (normally) in the pipe about 6cm away from the end of the pipe ...nearest the black plastic resonator thingy