Gallen

Hi guys,

Well today must officially be the day of boost problems!
(I've had a quick look at the ones already posted but not the same!).

I've had my VIC test done this morning (all was fine) so the Scooby is now officially on the road as far as VOSA is concerned!

I drove it properly for the first time today to the test center - She runs and sounds absolutely gorgeous.

However I am a little disappointed as I have noticed something that's clearly not right... Teething troubles I'm hoping!

- The car boosts, but almost in pulsating sections - I mean it starts to boost then cuts boost, boosts then cuts boost... around 4 or 5 times when under load on pick up, until gear change. It's not a violent cut of boost like the engine is mis-firing (it's not mis-firing).

It's almost as if there's a loose connection or blockage somewhere... or I have thought of fuel starvation??? There's no smoke and eveything else sounds fine, temperature appears spot on etc etc and runs perfectly when not boosting.

I'm going to have to look in to it later so was just wondering if you had any clues as to what I could check for or look at - I'd be very grateful.

All the best,

Gallen.

RuskyV

Are you getting an intermittent engine light? I had a problem simlar to this but it's gone away since I've used v power fuel, well at least for the last 3 weeks or so anyway....

What fuel are you using?

Gallen

No engine light (that I've noticed).

Currently running on Esso Supreme 97 as the tank was almost empty this morning (its been standing since January) so stuck 20 litres in... Ideally would have been Tescos super (which the Starion liked!).

SiofChester

iTrader: (2)

First step would be to get some new plugs put in - gap them correctly and then clean out the boost solenoid

Splitpin

I used that Esso "Super" once. It was sh*t. I couldn't imagine 95 RON being worse. Anyway that's a side issue.

Gallen - would help us a bit knowing what sort of car you have and what the engine spec is. Pulsation of the sort you're describing could be any number of things - we're going to need some base to work from before being able to provide targeted suggestions. Si's suggestion's as good a place to start as any though.

newman90

dont supposed it has been de-catted recently? or sports cat as this could cause over fueling etc, and will splutter may need a remap

tathan

If it's been off the road for a while, the ECU needs to relearn.

LegacySTi

iTrader: (13)

1. Turbo intake pipe under manifold onto turbo. Rip/small hole as it gos onto turbo.

2. Crack in exhaust housing at wastegate.

Splitpin

I know you mean well but that's b*ll*cks and not really helpful. If it's not running stably after a reset/power removal, there's no way the learning functions in these ECUs will bring it back in to normal running. The symptoms described are consistent with an tangible problem, not of an ECU that needs to "relearn".

Gallen - the sooner you can give us some more detail the easier it will be to advise you.

tathan

Hmmm. I've had spluttering and boost wavering after an ecu reset that cleared up within a few miles once. That said, the other xxx many times it's been fine.

LegacySTi

iTrader: (13)

not ecu, not plugs.

Mrchips

iTrader: (7)

Get the car into test mode, this is the grren connectors under steering wheel. OR could be the black ones. Can't remember which, and you'll here the solenoid clicking, this is good as you can spray brake cleaner or carb cleaner into solenoid, or course you should disconnect pipes first, but remember which way round they go. Also spray cleaner into pipes, just cake it in it.

put back together, give the ECU a reset whilst your at it, might as well.

Go for a spin. Should be sorted.

The boost problem is caused by a bit of oil in the pipes, this in turn causes it to over boost and under boost.

Gallen

My internet went down last night so I coulsnt reply until now! Sorry.

Thanks for your replies - I really do appreciate every sigle one of them.

Ok, spec as follows:

2000 UK Spec 2000 AWD Turbo
Full Decat Scorpion exhaust
STi Panel Filter
Dump Valve (Bailey I think)

Ok, I did some research and spoke to the previous owner.
He said he had not experienced the problem before - maybe he did, but didnt notice........

I used the Esso 97 yesterday and re-filled with £40 of V-Power.
Still no difference, didn't think there would be but it was simple enough to try! Always start with the easy things!!!

I did take a look under the bonnet and found that the small hoses to the Solenoid have been replaced with generic looking blue hoses - certainly not done very well. There's no jubilee clips or anything and also the presence of these pipes leads to the possibility that the restrictor "pill" could be missing (Anyone got a diagram so I could check???). Worth a thought about this???

Additionally the previous owner said I should check the MAF sensor - he had it replaced shortly before the accident but is not sure they put the correct one on! (Any one know which one I should have for the model/year + how I can tell - Are they numbered?).

Ok, I think I should try cleaning the Solenoid using Brake/Carb cleaner. It makes sense this could be sticky due to standing unused for so long (it's been started but not driven properly). This I think should be the first port of call.

Secondly, I will look at replacing the hoses back to stock - A trip to the Impreza Breaker in Norwich may be on the cards on Saturday Morning! I will re-fit these (hopefully in one "chunk") with all the correct fittings and Pill intact.

If this still doesn't sort the problem then I will perform an ECU Reset.

It's annoying as I have a VF34 turbo, a SARD fuel pressure regulator, a Walboro 255 on order and have found a Simtek ECU that I am hpoing to buy... before going to Jollygreenmonster to have the car custom tuned on the rollers)... obviously I need to cleanse the car of existing gremlins before even thinking about this (Grrrrrr!).

If anyone's around Frinton, Essex on the weekend and can help I'd appreciate it! ;-) (worth a cheeky ask huh!)

Are there any gudies/diagrams/DIY's on this stuff??? I'm a Scooby Newbie!

Thanks guys by the way.

Gallen

Gambit

iTrader: (6)

is it not bad to run a full decat system on a std ECU? causes overboost?

Splitpin

Thanks for the extra info Gallen. Some comments:

1. Cleaning out the solenoid and boost control pipework to eliminate any oil contamination is definitely worth doing.

2. If the boost control pipework has been replaced by softwall silicone stuff from ye old chav tuning shoppe, all sorts of weird pulsation/fluctuation issues can ensue, and one of the things I was waiting to ask you is whether the pipes were non-standard - which we now know they're not. If cleaning them out doesn't help, replacing them with standard is definitely worth doing. The one running from the solenoid back to the inlet pipe is less critical, but the two short pieces either side of the tee, and the long run from tee to solenoid are critical - any tendency to balloon will send your boost control all over the place.

3. It's easy to check whether the pill's still there by pinching the pipe along its length - you'll be able to feel, if not see it. Sounds like it's still present as otherwise you wouldn't so much be getting "pulsating" boost as almost none at all. If it's there, check it's in the right relative position in the pipe. It should be about 30mm away from the tee.

4. If you do get some replacement pipework off another car, make sure it has the right size restrictor. You need a 1.2mm diameter one - not an STi-type 0.9mil. Also if the car has uncertain history, it's worth taking the one you've got out (assuming it's there) and checking its diameter by seeing whether a 1.2mm drill will pass through it. If a previous owner has attempted a cheap boost hike by fitting a smaller one, it's something you need to check for.

Also, reading between the lines would it be correct to say you bought the car as an accident damaged non-runner? If so, and doubly if the impact was at the front end, it would be worth fitting a new airflow sensor on a precautionary basis - unless you have the ability to datalog the ECU to rule out damage to it.

Indeed as far as diagnostics go, have you got a boost gauge, or a laptop acquiring data so you can measure the size and frequency of these boost pulsations? Your car should under most circumstances be able to handle a turbo back decat without undue mucking about but there are always exceptions and thus Gambit may have a point. If you know the actual boost levels we're talking about here, that would rule in/out some of the possible explanations.

Gallen

Cheers guys......

Yes the car was a very light (superficially) damaged vehicle. The guy who I bought it from had the prang and bought it back from the Insurance company as he planned to repair and keep it himself... He had it about 2 years prior to this. Strangely enough the garage where he had bought it from (prior to the accident) belongs to a freind of mine who only sells MINT cars... so it has a FSH and lots of paperwork

Damage consisted of:
2 x N/S Doors which are still on it unrepaired as they are only scraped/dented.
The gearbox was shot to pieces after a poor re-build (drove but sounded staright cut!) so we replaced the box (TY754VN1AA).
The rear wheel handbrake was also locked on - Bought believeing the buyer who said the rear Diff was seized, but it turned out only to be the handbrake stuck on.

The car is Cat C - probably due to insurance inspector assuming the gearbox was done in the "accident" (more of an incident!). I cant see how it could have been myself.

Runs/Drives beautifully now, apart from the strange Boost Pulsations.

No Boost guage - I need one as it would help!

RE: Diagnostics, we do have a lap top with some software and a freind has the Snap On Modis (I think its the Modis). Can you suggest any specific software for the Scoob?

Gallen.

Splitpin

Okay, chances are the Snap-On tool will barf if you plug your car in. 99-00 Imprezas aren't OBD2 compatible (despite having the correct physical plug) and so generic OBD tools don't usually know what to do with them. You need something that speaks the Subaru diagnostic language.

To read your car on a laptop you need an ISO9141 bare interface (Gendan sell a suitable one here). The ECU Explorer software they link to doesn't have any bells and whistles but does what you need - and is a free download.

However before doing anything else I would clean the pipes out, check the restrictor bore (assuming it's present) and, if in any doubt at all about the stiffness of the tubing, replace with some pukka stuff.

Also, re the MAF sensor. I've seen one broken in the past by a very minor frontal impact. They really don't like vibration so a precautionary replacement is a possibility. However if you don't fancy speculating with a hundred quid's worth of sensor and are going to set yourself up with a laptop, you can use that to assess how reliably it's working.

sc_sjo

iTrader: (7)

Sorry to hijack, but if this is a generic OBD2 cable how will it work with the SSM pinout in the 16 pin DLC?

Gallen

My freind altready has something like VagCom...
Do you reckon the lead will be the same?


I think its flimsy s*** in that's been used. Will clean Solenoid first as you suggest, then go from there. Even if it is the solenoid, I will be replacing this tubing asap, but want to route out the cause first.

Not a bad idea! ...Do you know what MAF should be on my car, Stock?

G.

Splitpin

It works fine. Subaru use the standard ISO9141 format for the physical connector and electrical configuration on these so the K-line runs through pin 7 exactly as per a full OBD2 car. You can use a dumb/bare ISO interface without problem. The ones that don't work are the intelligent sort with their own onboard command interpreter, like those based on ELM3xx chips. These will only work in OBD2 mode.

Yes, vag.com interfaces are bare ISO so should work fine - give it a try with ECU Explorer and see how far you get.

The tubing might well be the cause - but clean the pipework before you junk it so's you know what's making a difference (or not).

There's only one type of sensor that should fit - although it's unclear from your previous post whether the previous owner got one from a main dealer, or got a third party part.

Standard sensor has a part number of 22794AA010 from your nearest Subaru dealer, or slightly more reasonably priced genuine parts from AS Performance or Import Car Parts. As above if you are going to look at logging the car you can get a pretty good idea of the sensor's health from that, so it's up to you whether to do a precautionary at this point or wait til you've had a chance to evaluate it.

Incidentally does the sensor in the car at the moment have a stripe of green paint across the top of its mounting flange, and white text (probably illegibly) printed down the side? If it doesn't, either it's very old, or is a non-genuine part, and either of the above would make it a candidate for elective replacement.

Gallen

Hi guys - Want to update you:

The MAF sesor DOES have a green stripe. The white lettering is there too..........???

Anyway, last night I put the car in test mode by connecting the under-dash wires to clean the solenoid.

4 long flashes then 4 short flashes - - - - . . . .
I think this points to the "HO2S heater control circuit high bank 1 sensor 3"

Anyway, I removed the pipes to the Boost Solenoid and cleaned it whilst on Diagnostic Mode with the brake cleaner. I cleaned the pipes and their connections, let dry and re-assembled before test drive... This has fixed the problem!!!

I repeated the process after returning from test drive just to make sure it was as clean as could be. I'll probably do it next week again, incase it pulls a little more cr@p through if the brake cleaner has dislodged some.

...Thanks for your advice here - fantastic result.

Next step - replace chav hoses with OE ones with the pill, and fit a boost guage (Can anyone recommend one? I'd like to replace the rattly dashboard storage bin with a dash-mounted guage set (or even a live feed digital diagnostics/feedback gizmo.....so recommendations most welcome and appreciated).

In regards to the fault flashes (44) can you advise???

Thanks,

Gallen!!!!

chris-RB5

Code Fault
11 Crankshaft position sensor

12 Starter switch

13 Camshaft position sensor

21 Engine coolant temperature sensor

22 Knock sensor

23 Mass air flow sensor

24 Idle air control solenoid

31 Throttle position sensor

32 Oxygen sensor

33 Vehicle speed sensor 2

35 Purge control solenoid valve

42 Idle switch

44 Wastegate control solenoid valve

45 Pressure sensor / Pressure exchange solenoid valve

51 Neutral position switch

Gallen

Thanks chris-RB5! I guesse that makes perfect sense...

Is there a way to clear this?

Gallen

Gambit

iTrader: (6)

reset the ECU

chris-RB5

ECU Reset and Error codes
Turn OFF the ignition

Connect Error code Connectors and Test Mode Connectors :
2 black connectors under dash, connect black to black and 2 green connectors under dash, connect green to green, they are by your left knee when sat in the drivers seat and often taped back to the loom if they haven't been used before.

Turn ON ignition but don't start the engine

Engine Check lamp comes on

Press accelerator pedal to the floor

Then return it to the half-throttle position and hold it there for two seconds

Release foot off the pedal completely

Start the engine

Check engine light error code is indicated by Pulsing lamp

If an error is detected then Check the ECU Code

If no error is detected - drive the car sensible for a couple of minutes
i.e. until warm (do not use boost or high rpm!)

When the ECU has been reset the Check Engine Light will flash

An Error Code is indicated by a flashing check engine light
of varying length of flash,
a flash of around once a second is the okay code and indicates all is well.

If an error code is detected Check the ECU Code

Turn ignition OFF and Disconnect Connectors

If there is a fault Check the Appropriate Sensor

Splitpin

Good result! As the others have said, 44 is the boost control solenoid. While you were checking/cleaning it all out, did you unplug it while the ignition was on at any point? If so, this will be enough to trigger the 44 error.

As has been said, reset the ECU and see if it comes back. Chances are that it won't.

Chris: That "reset" procedure you've just described is correct but a little bit too flowery. There's no need to bother with all that stuff with the throttle pedal prior to starting, nothing gained by doing so. Just connect both sets of connectors, start it and drive until you either get error codes or the even on/off/on/off "OK" sequence from the CEL.

You have no choice about not using boost, btw, as the engine will be in limp mode.

Gallen

Yep - A REAL result (let's hope England can come up with one later!)

....so I just connect black and green plugs and drive it (gently)?

What if I still get the flashing? (or will this disappear after a period of driving?). Would this mean a new boost solenoid?

p.s. Sorry for the amount of (?'s) in this post! ;-)

G.

Splitpin

Yep, connect the black and green plugs and drive it gently. After a period of time - which could be a few seconds if the engine is already hot, or up to 3 minutes if cold, you will either get a regular on/off blinking from the CEL, or you will get the long flash/short flash error code sequencing you've already seen.

If you get the regular on/off/on/off continuous blinking pattern, that's the okay signal - at which point the reset is complete, so you can stop the engine, disconnect the plugs and drive as normal.

If you get an error code, that means you have an active ongoing error that needs to be investigated. As above, I suspect you will get the all-clear.

Gallen

Thanks Splitpin... I will do this tonight.

I love the car - A real addictive drive. I have 2 x Diesels at home but cant stop using the Scoob (especially for work - £££120 miles a day, which I will nip in the bud - after today of course!!!!)

Anyway, I noticed the boost solenoid slightly pulsing again this morning. A new one from Subaru is a stonking £170+VAT!!!!

Is it worth swapping to something like a "PERRIN 3 PORT BOOST CONTROL SOLENOID"??

They are cheaper but sound much more appropriate... (Remember that I am planning on switching to a VF34 (I already have one under the table in my spare room!), Either a Simtek or ECUTek and Walboro 255.


...further to the above (and where I know my "newb-ness" will be obvious ), I have 2 pipes in my existing solenoid. 1 is the L-Shaped pipe on the side, the other is the straight pipe at the base.

Where would the 3rd pipe go on the 3-port?

Thanks,

Geri
(Gallen)

Splitpin

You said the other day that the problem was fixed after you cleaned the solenoid and boost control pipework out - but today it's back. Therefore the likeliest explanation is a recurrence of oil contamination, and before going any further the first thing you need to do is rule that in or out. Clean the solenoid and pipework out again and see if it cures the problem in the same manner.

If it does, the likeliest cause is too high an oil level causing excessive amounts to be vented out of the breather system. There's another less likely (and pleasant) cause of excessive vent oil but we'll deal with that if necessary. Check the level on a flat surface about five minutes after switching the car off (and with it fully warmed up). If it's any higher than the top hole (that's the hole, not the notch), you can probably cure this by draining a little oil out.

To answer your question, a direct replacement two port should be a fraction of that price from a reputable Subaru breaker. You can't fit a 3 port solenoid, connected as it should be, without an immediate remap (or ECU swap) so you would have to factor that into your cost/timing calculations. You can, however, configure most 3Ports to run in 2 port mode. If you did decide to change the solenoid, whether you would buy the Perrin product when there are others around that do the job at least as well for less money is a separate issue.

All that said though, I am personally not a fan of fitting modifications to try and solve problems where it is unclear what the source of the actual issue is. As above the first thing to check is whether this is boost control pipework glugged up with oil. If it is, check and see if it's the obvious cause. If the oil level's not the cause, move forward from there.