simonds1

All three things are Denso dude, and none of them have ever been changed from standard to my knowledge. All still original from when the car was new. Here's a better pic of it.....



The label on it kept coming out looking as if it was a blank white sticker in the other pic for some reason!

c_maguire

Yes A is the boost solenoid.
I believe earlier on Splitpin told you to connect the two green plugs under the steering column together, then turn on the ignition, at which point the rad fans come on and various solenoids start clicking. If you unmount the boost solenoid A, disconnect the two rubber pipes and then do the green plug thing, you can clean out the solenoid. I find an old washing up liquid bottle with some clean petrol in is good for giving it a good clean by squeezing petrol in one of the two stubs and it should flow out of the other.

Kevin

c_maguire

Looking back I can't find the green plug reference, probably in another post I read recently, but the plugs are very close and similar to the black ones you connected to do the error reading.
B is the standard MAP sensor, is generally reliable, and also £300+.

Kevin

joz8968

iTrader: (13)

No worries. It just looked after market as it's held on with only one of the bolt holes. Very un-OEM.

simonds1

Oh yeah!! Didn't notice that before! I wonder if they're all like that then? Or does this mean there's a possibility mine has been fiddled with at some point?

joz8968

iTrader: (13)

This is the question? But I think Denso are indeed OE, so prob not.

Bottom line it's only a MAP sensor anyway, and the boost target is what it is LOL

simonds1

Just to update, I've cleaned the boost solenoid today and it's made no difference whatsoever Sooo.......

How on earth do I do this then!? Sounds complicated! lol

joz8968

iTrader: (13)

You bypass the BCS/MAP/PES by temporarily running a length of vac hose direct from turbo compressor cover nipple to the wastegate actuator nipple. This is obviously bypassing the BCS/MAP/PES so the ECU/electronics are effectively "blind" to the boost pressure and it's only the raw, mechanical, w/g actuator's spring-opening pressure that should be present e.g. around only 0.5bar/7psi, or so.

If there's no pressure whatsoever, or much lower than that stated above, then suspect knackered w/g (e.g. a broken spring or split diaphragm)... or possibly the w/g 'penny' flapper in the turbo is, er, flapping around loosely... or something else up with the turbo itself.

simonds1

Just another update..... Finally heard back from Bob (he's been on holiday), and he thinks my ecu is going into 'drive by' mode, which is a feature inbuilt into the ecu software, and under certain circumstances of speed, throttle position etc, it switches off the boost control solenoid so you only get actuator boost? Other people have also noticed I was only getting actuator boost in the problem areas of the log files, but nobody else has come up with this 'drive by' mode as a reason for it. I am convinced something is wrong tho......I mean I've had the car for 4 years and this has never ever happened.......and now it happens constantly Something must have changed recently. I was tempted to just buy a new boost control solenoid to see if that solved it, seeing as cleaning mine didn't make any difference. They are £125 tho. To be honest I'm willing to spend that just to try it, cuz I really can't cope with all this not accelerating for much longer!

c_maguire

Don't spend your £125 just yet, there's a good chance it'll not fix it.
Did you get logs in the same gear accelerating flat out with and without the fault occuring, your last logs had expired when I tried to look.
And have you used a boost gauge to see if boost drops to actuator pressure when problem occurs (c. 0.5bar)?

Kevin

simonds1

Well.....I have never managed to get a log of it with and without the fault occurring for the exact same bit of driving if y'know what I mean. Like I wanted to be going along at a certain speed, at a certain rpm, in a certain gear........then foot down and get it to accelerate properly........and then also go along at the same speed, same rpm, same gear as before.......then foot down and get it to not accelerate properly. That would give two good situations to compare then. But as you all know with intermittent faults.......do you think I can bloody get it to go wrong when I want it to?!?! lol.

I'll have another go tomorrow night and see how I get on

TimH

iTrader: (11)

Drive by mode is definitely activated at a very specific rpm etc...could it be that despite not noticing it for 4 years, now you *have* noticed it, and in trying to replicate this 'fault' you are simply getting very good at activating this mode!!??

I remember this on my 98 wagon, and it usually caught me out just when some have-a-go Nova driver successfully goaded me

simonds1

Nah Tim it's definitely just started happening recently and never before. I mean there are some hills around here that I actually have trouble getting up lol, that's how bad it is! There's a really steep hill that I go up a few times a week, starts with a 90degree bend at the bottom, so you literally cannot get any sort of a run-up to it at all, you just have to crawl round the bend, and then accelerate.......and well......it just won't boost or pickup or generally do anything at all! It's devastating like. Normally go round there, dump my foot as soon as I'm on the straight and wooosssshhhhh just get taken up like a legend. Not anymore tho

c_maguire

This problem didn't coincide with any work done on the car such as the service you mentioned did it?

simonds1

No it didn't coincide with anything I'm afraid, it just randomly started happening on a drive back home to South Wales from Bristol. Car just started feeling really 'flat' on the motorway. Usually only takes a tiinnnnny touch of the throttle and it just picks up and goes like a rocket, but I was having to really put my foot down and still get nothing! Been happening ever since then. Last thing done to the car was a major service in October last year, and this fault only started happening on April 4th this year.

The mystery continues!.....

Splitpin

Simonds - apologies for the silence over the last couple of weeks, have been working away and decidedly snowed under. Still need to have a proper read of your logs and will catch up on the progress of your thread later.

simonds1

Hi Splitpin, that's fine don't worry, thanks for getting back to me. Hope you weren't working too hard! Do you want to PM me your email address and then I can send you the logs? Unless you have already downloaded them from before? Cuz all the links have expired now on mailbigfile, so you won't be able to download them anymore

Splitpin

Yes I was working far too bl**dy hard. I got your big log when you first posted it so no probs there Have just had a look through it and a couple of things stick out.

Regarding your suggestion that there's always much more ignition timing when things go wrong, as has already been said, this looks like a symptom of the problem rather than a cause. Given that you have much less boost when it acts up, you'll have much less engine load and therefore the ECU will be setting the timing from different (and much more advanced) sections of the ignition maps.

There is no small amount of confusing and contradictory evidence here, but the one thing this doesn't appear to be, at least if my understanding of the way it works is correct, is "drive by mode", "emissions mode" or whatever you choose to call it. I could be wrong (I'll double check), but when that is activated, it overrides the boost solenoid duty setting and runs the turbo on straight actuator pressure. In this case you should see zero percent boost duty cycle in your logs while it is "misbehaving".

Yet in your logs, when you floor it and the car goes wrong, you're still seeing wastegate duty respond normally - and as you see elsewhere in your file. In the bit where it goes wrong in your long file you can even see it jumping all the way up to 91% (which is the absolute maximum possible) before pulling back to 81.9, presumably because of passing from one cell of the max DC map to the next.

However, all of that said, it's noticeable that the bit in your "long" log where it goes weird, you are on steady low throttle for about 12 seconds before you shoe it (from 47:31.1). Although, that said, in your earlier fault log, the one you posted as a .jpg, you're in third gear, which suggests this isn't the "drive by" mode (which tends only to affect second). The other times you've seen this behaviour occur, have you been sat on consistent part throttle for a few seconds before suddenly accelerating, or...? Appreciate it may be difficult to remember now, but have a look at your other logs and see what they tell you.

This still, on balance, seems to point in the direction of Matt's earlier suggestion that "something" physical, under the bonnet, is intermittently preventing the turbo generating boost properly. Connecting the compressor outlet direct to the wastegate as has already suggested and doing a couple of logs like that would worthwhile. It'll help us see how your turbo spools up on bare wastegate pressure, which will be a good basis for comparison with what happens when the car acts up.

Cleaning the boost solenoid, and the bleed return pipe that leads from it back to the inlet pipe, would be worth doing. The other possible explanation is something like a sticking wastegate actuator. Have you explored that area in any way?

In the meantime I'll have another look at that drive-by mode thing and remind myself how it works. If it does turn out to be that, given that you've already paid for an EcuTeK licence, it shouldn't be beyond their goodwill and intent to support their customers and mappers to disable it for you.

simonds1

I'm glad you think that! I understand that you still need to double-check how the 'drive-by' mode works to be sure, but I was saying to Bob I thought it was very strange that a) my car suddenly wants to go into this drive-by mode all the time after not ever doing it for 4 years, and b) if it is in this mode as some sort of a safeguard against something, why would it come out of it mid-accelerate!? Surely it wouldn't do that?

I've been meaning to ask something for a while, but don't really know how to explain it! Here goes........y'know the 'primary wastegate duty cycle' value in the log files? I'm guessing this is the opening/closing of the wastegate? So how far open or closed it is sorta thing? So assuming that.......does the value show the actual 'position' of the wastegate, or the intended position of it, if that makes sense?! Like is the '91%' value showing that the wastegate has been instructed to go to 91%, or is it actually at 91%? Or to put it another way, I spoze what I'm asking is......if I had a sticking wastegate, would you be able to tell that from the logs, or is it something that just isn't recorded?

Not reallllly no. I mean, without trying to sound stupid here......driving around generally mostly involves being on constant partial throttle if y'know what I mean? Not obviously having the throttle in the same actual position for a while tho, which is what I assume you mean? I mean the problem happens when I'm going along at partial throttle and then floor it, and it also happens when I come off a roundabout and then floor it, so I would say that no it doesn't only happen when I've been on consistent partial throttle for a few seconds before hand.

I did this on the weekend, and to be honest while I was doing it, the pipe & boost solenoid seemed to be producing some dirty oil-ish looking fluid when I was first cleaning them, so I thought yeahhhh, this is the badger!! But no, it made no difference whatsoever unfortunately

Haven't really explored that in any way, but yes it was probably the first thing I thought of back when it first started happening. I mean it would make perfect sense wouldn't it? Altho it wouldn't make sense if the log files show the actual wastegate operation, like I was asking about earlier - because that seems to be correct at all times in the logs doesn't it, even when the car is suffering from the problem?

That sounds complicated! What does that actually involve? Will this determine if the wastegate is sticking or not? To be honest I've thought a few times about just buying a forge wastegate actuator just to see if it solved the problem. This one....

http://www.forgemotorsport.co.uk/con...oduct=FMAC4SUB

I mean back when I had another probelm (loud hissing like escaping air under acceleration, and no performance etc), I guessed it was a dumpvalve related thing so I bought a forge dumpvalve......and hey presto I was right. Car was back normal again then. When this first started happening I thought hmmm wastegate and was just gonna get one. But then I think I read about having to have the exact spring tension or everything would be wrong, and I might even need another remap after a new actuator......and then I think I got a bit scared and just forgot about it lol. I don't actually know how complicated or not fitting a new actuator is? I mean the dumpvalve was a piece of ****, even I could do it

Anyway, I think I'm rambling now. Time for a cup of tea I think!

joz8968

iTrader: (13)

Could it be a faulty MAP sensor, maybe?

Splitpin

There's less need to do that now given what you've just said...

Yep, that's a big chunk of evidence to suggest that it isn't this drive-by thing.

Ah, yes. This is significant. The drive-by thing. If it comes on, the only way to clear it is to let the throttle drop fully back to idle. In other words, if you've got an acceleration run somewhere where it started mucking about, and then suddenly cleared up without you lifting off the throttle first, then it ain't the drive-by thing wot caused it.

Not quite. WGDC is (effectively) the amount of power being applied to the wastegate control solenoid, which, as its name suggests, affects the opening of the wastegate but is not exactly the same thing.

The wastegate actuator is blown open by boost pressure bled off the compressor outlet - so, if you were to imagine a pipe running direct between the two, as soon as the amount of boost produced starts to exceed the pressure of the spring in the actuator, the gate will open - hence the term actuator pressure.

In its default, unpowered state, the boost control solenoid effectively allows that direct pipe to happen - so bleed air passes (via the restrictor) to the wastegate and you basically get actuator pressure. When the solenoid is powered, however, the bleed air from the compressor is given an easier escape route back to the inlet tract - thereby taking air pressure away from the actuator, and keeping the wastegate shut (or, in practice, less open).

As such, the wastegate duty cycle figure you see in your logs sortof corresponds to the amount of air being prevented from reaching the wastegate. In practice this means that the ECU is mapped to allow a higher maximum duty cycle at very low engine speeds (and high throttle angles) in order to spool the turbo quickly, but this will then drop down at higher engine speeds, and once the boost is within target, the ECU will apply error correction to reduce or increase the wastegate DC to keep boost within the desired target window.

If the boost goes above the target, the ECU will react by cutting the duty cycle, thereby sending more air to the wastegate and bringing boost down. If the boost drops below target, the ECU can add some duty cycle, closing the wastegate and bringing the pressure back up. Make sense?

No the position of the wastegate itself isn't recorded. As above the duty cycle number you're seeing is the amount of power going to the solenoid. Thing is, you shouldn't, really, see the wastegate sticking open, as there's quite a strong spring in there to pull it shut. About the only way it could stick is if, for example, there's a cackload of rust or some other sort of foreign matter around the end of the shaft where it goes into the actuator. It's always possible though so might be worth taking the heatshield off and having a looksee what's going on in there.

Yeah, of course. Thing is that thing the others are on about requires the throttle to be held with a very tight range (i.e. hardly move at all) for a number of seconds. Under normal circumstances, as you suggest, your foot moves up and down too much to trigger it.

In which case, again, that isn't (or certainly shouldn't be) the boost limit mode, whatever the hell Subaru call it! You've got to be on consistent, basically unchanging, part throttle for a good few seconds before it triggers.

I need to go through some firmware disassemblies to relocate the routines but I'll be able to come up with a definitive answer on that one. For what it's worth I'll also check that ECU Explorer actually reads the final, corrected wastegate DC used to program the solenoid driver too.

No, not at all, really simple! Just remove the pipe from the compressor bleed takeoff, take the other end off the wastegate actuator, and use a bit of stout 4mm tube to link the bleed outlet and wastegate actuator direct together.

It could potentially highlight that kind of thing, yes. If you have a direct actuator connection you're effectively removing the boost control system from the engine. If it starts to act up and lose boost under those circumstances, the wastegate actuator, or some bizarre failure within the turbo itself (or, at a pinch, some even more bizarre and inconsistent leak).

What it definitely should do, if you log the results, is give us the opportunity to see how your turbo behaves with a direct actuator connection. This will, by implication, then allow us to see whether the behaviour is the same as when your car is in its "error" state, and will tell us more about that error as a result.

I wouldn't go that route just yet. As you say, without being certain you've set the opening pressure right you could make the situation more, rather than less confusing if you're unlucky.

Doesn't look that way from the logs. The pressure readings are all consistent and logical, you've got the atmos pressure readings sitting there all the way though without giving any rogue reads, and the - boost control solenoid is clearly responding to increases in throttle opening on the basis that the pressure inputs are correct.

simonds1

Well we can officially rule that 'drive-by' mode out then, because yes the problem can be present when I put my foot flat on the throttle, and then it quite often starts to boost suddenly after 4 or 5 seconds of foot being down....without me coming off the throttle at all.

Okay, I understand (one of the very few things I do understand lol) so it is possible my wastegate is sticking then. Unlikely as you said, but I'll have a look for anything out of the ordinary in there.

Noooooo, that bloody heatshield!! Such a pain in the **** to get at! Talking about the heatshield has reminded me of something, which is definitely worth mentioning while we're on the subject of my wastegate possibly sticking. When I pull away from a standstill, there is a rattle at lowish revs in 2nd gear. I can't really remember when this rattle started happening, but it was much longer ago than april 4th when this non-accelerating problem started. So anyway.....I spent many many hours trying to secure my sodding twatting pain in the bloody **** heatshield cuz I was convinced that was what was causing the rattle. I found most of the bolts to be missing, and it wasn't even on in the right place, etc, etc.....so I was pretty sure when I replaced all the bolts and fitted it correctly I'd have sorted the rattle out...........but no. Still there. So I started knocking the heatshield with my hand and putting my hand on stuff to see if holding it stopped the rattle, as y'do........and it turned out to be the 'shaft' that goes from the wastegate bit to back in under the heatshield. if I put my finger on that shaft and start knocking things nearby with my hand, there is no rattle. If I take my finger off that shaft and start knocking nearby things, it buzzes/rattles. I don't know if this might be related to something that might intermittently affect it's operation? There doesn't feel to be any 'play' in the shaft if I try and move it about like. But yeah, thought I'd mention that just incase it could mean something.

I'll take a photo before hand just to confirm I'm putting the right pipes together lol. I doubt I'll have time to try that now until sunday.

I think that's it for now. Thanks again for all your help Splitpin

fantasticmrfox

so what was the diagnosis in the end ?

simonds1

No diagnosis yet dude. Still haven't found the problem. I still need to try the thing Splitpin told me, which is....

But I haven't had time and am off to Germany on wednesday for a week so probably won't get a chance to try it until after I'm back. I've become convinced that I've got a faulty boost control solenoid so am really tempted to just buy one and try it. Might have a look round some scrapyards and see if they've got one I can at least try and see if it's any different like. I don't really wanna try a 2nd hand one tho cuz if I happen to try a duff one and then think the problem isn't that because it made no difference.......I will never ever solve it! Need to try a new one ideally so I know it works. Ah well, I dunno what I'm gonna do yet. I'll update as soon as I've tried Splitpin's test tho, or if I find out anything else in the meantime

olliecampbell

iTrader: (3)

Just have to say that this is a great thread guys. Really interesting bits in here. So much so I've bought a snazzy cable for myself too so I can have a look at whats going on under the hood of my ECU

simonds1

Hey guys, just wanted to update you on what's happening. I've been away in Germany for a week like I said. On the way over to Germany we stopped off at a place called 'SVA Imports' in Dover and I asked the guy there if they had any imprezas they were breaking, or any second hand parts lying around etc cuz I was looking for a boost solenoid to try on my car, and he said no but he put me in touch with a guy called Andy at 'Grade A Subaru' and I've emailed him and he said he's got one there and I can have it for £25. So I'm just waiting to hear back from him now to arrange payment & delivery etc and then I'll have a boost solenoid to try and see if that solves the problem. I'm thinking that will solve the problem to be honest. But we'll have to wait & see! I'll report back when I've got the new solenoid and I've tried it out

simonds1

Hey guys, just wanted to update you all and I'm pleased to say......it's good news!!

That Andy guy from Grade-A Subaru just stopped answering my emails all of a sudden and then I couldn't get hold of him again! So I ended up managing to find another 2-port boost solenoid on ebay for £25, and that has solved the problem!! Car just feels proper lively again and it's just as if I've got a whole new throttle system which feels like it's properly connected unlike before. Every little tiny throttle movement results in some kind of acceleration from the car so it feels SO lively compared to what I've been used to since the problem started happening. I don't really wanna curse it, but I guess that being an intermittent problem, and the fact that I have only actually driven the car twice since changing the solenoid.......there is a very slight change that it's made no difference at all and it happens to be fluke that it's working now. I reckon it's sorted it tho for sure. Too much coincidence for the car to feel so good after me changing it. Time will tell!

Just wanted to give a huge thanks to everyone on here who helped me along the way. Like someone said earlier on, this thread is exactly what forums like these are all about. It was so interesting for me to be part of it, and in the end, we got it sorted!

Massive thanks again guys, and hopefully I won't need to speak to any of you soon Hehe

joz8968

iTrader: (13)

Has it cured it totally? Does it boost very smoothly with NO transient hesitations whatsoever?

If so, then excellent - you've fixed it for paltry outlay.

dnc

Good to hear it's fixed and hope it stays that way. Amazing responses from Joz and, in particular, splitpin. I know what to do when I have problems

simonds1

I'm pretty sure it's fixed completely now yeah I went on the same route as when I was doing the data logs (but I didn't actually record a log, maybe I'll do that at some point) and like every place I accelerated in the certain gears I was always doing it in etc.....couldn't fault it on any of em.

If anything does happen, or I notice any hesitations etc, I'll report back. But hopefully I won't need to