big_jimbob

Hey guys, I recently bought a 2001 Bugeye WRX

I noticed that it has some hesitation on boost, when in 1st and 2nd it isnt very noticeable as you are through these gears so fast but in 3rd and 4th it seems to get to about 3k then boost as it should, hesitate about 4-5.5k then boost hard again....

It does still pull through 4-5.5k but there is a noticeable lack in power then gain again....

Im guessing this isnt normal........

Iv replaced the bailey dv with a standard one, as i read these can cause some issues, iv also found in the history that scoobyclynic had the car in for some hesitation issues in 2008ish and they replaced the MAF sensor...

Iv also replaced the exhaust with a standard 2 cat one rather than a cat (downpipe) back stainless system....

There doesnt seem to be any splits in any intake pipes as iv had these off today too....

Im just getting fed up of not knowing what the problem is!!

I have a boost gauge on order so i can make sure it is boosting correctly and holding boost....

Any other suggestions??

Thanks
Jim

scoobynash

Hi Jim.Sounds like it could be the boost pressure solenoid cutting in and out.Have you or can you check if there are any faults in the engine ECU? Could try a manual boost valve.

big_jimbob

I havent done, how would I go about doing this?

also is the boost solenoid the piece behind the air box under the black plastic cover?

is it a maintainable item or in need of replacement if it messes up?

Thanks
Jim

scoobynash

You can take them off and clean them.I think there is a thread for this in the archive. Be careful when removing the vacumn pipes.The plastic piping can break easily.

rapid.STI

iTrader: (5)

http://www.scoobypedia.co.uk/index.p...ontrolSolenoid

there ya go fella,, hope it sorts it for ya.
wayne.

big_jimbob

Rite, so I connected the green plugs, removed the pipes and squirted cleaner through the solenoid...

It didnt seem to be going through the solenoid and out the bottom so I got my multi meter out and tested the power coming in it read as just short of 12volts.... (to be expected with the other items in the engine bay doing their test sequences(fan etc)

Then I dissconnected the green plugs and it still had 12volts at it!

I also noticed that when I refitted the connector the solenoid didnt make a noticable click and I couldnt feel one when I was holding it and connected the connector (with 12v) either....

Should the solenoid power open or power shut as with the connector on or off I couldnt blow air through the pipes either...

Jim

scoobynash

I would say Jim,that if you have live and earth to the solenoid valve and it isn't clicking and you cannot get any spray through it that it is probably farm trucked.You should have an on off voltage to it when testing.This would be the open and closed positions.I don't like doing telephone or internet diagnosis.But,that would be my proffessional opinion.

big_jimbob

It definatly doesnt click and yep u are correct with the green plugs connected it does go on and off with the fan..... (just been and checked)

Should I be able to blow through the solenoid with the power to it?

Thanks for all the help guys

Jim

ian.e

iTrader: (1)

Am sure the newage ones don`t click at all, think that`s just on the classics. I was trying to do the same on my bug. Is still on and working fine though.

big_jimbob

Should I be able to blow through the solenoid??

Surely if the boost is to be bled off then I should be able to blow through it??

Jim

scoobynash

Thats correct Jim.The valve should be opened to bleed off to keep from overboosting.

big_jimbob

So am I rite in thinking if it is stuck shut then im overboosting on full throttle and the feel im getting is the wastegate opening and shutting (as it gets too much boost) bypassing the turbo?

Thanks guys
Jim

Splitpin

Only when it is powered.

As above, only when the coil is energised. The valve is shut when unpowered. If you can blow through a two port solenoid when there's no electricity running through it, there's something wrong with it.

If the valve is stuck shut, you get underboost, not overboost. You can get overboost if it sticks open.

big_jimbob

Well with the green connectors together I cannot blow through the pipework.... (disconnected at both ends and ignition on, with fans doing their thing)

Ps. pipework is not blocked....

Is this rite or wrong?

Jim

big_jimbob

So im now thinking that if it is stuck shut and not bleeding off boost then im getting underboost....

therefore when at full throttle im gettling low boost and overfueling....

sound about rite?

Jim

big_jimbob

does this sound rite anyone? im going to pick up another boost solenoid tonight...

just wanted to know if im on the right track with the details iv given..

Jim

Splitpin

That sounds wrong. Take the pipework off the solenoid, remove it from the bracket (while keeping it plugged in) and try to blow directly through it from the "bottom" port (the one in line with the solenoid body). You should find that it alternates between "open" and "shut" every couple of seconds.

If it doesn't, try (briefly) energising the solenoid directly with a 12 volt battery - although this may be a moot point if you have another solenoid to try.

To correct an earlier misunderstanding...

Yes, that's exactly as you would expect. The solenoid is permanently supplied with 12 volts when the ignition is on. The driver in the ECU controls it by switching the "negative" side of the coil in and out of contact with ground - hence completing or breaking the circuit.

Reading up the thread, it sounds as though your boost control is normal through the majority of the performance envelope but drops out and then comes back again. These symptoms sound very similar to what is being reported by Stevo1970 in his thread. You would do well to read that and follow the advice I've written there - especially (if you don't already have one) with regard to the fitting of a boost gauge.

You may also find that taking the car to a Subaru specialist/tuner and plugging it in to diagnose will save you a lot of head-scratching. There are three or four likely causal paths for what you are reporting. You might get lucky in identifying the correct one first off, or you could be working through a process of elimination for a while. In the latter case, getting some first-hand expert attention to it would be something to consider.

big_jimbob

Thanks for your response...

The 12volts at the solenoid was read from the plug only, so negative and a permanent live was there with just the ignition on and green plugs disconnected...

Jim

Splitpin

No probs - just edited it subtly so it reads a bit clearer.

Yes, that's normal. If you switch your meter into resistance mode and then connect it between the "negative" pin in the solenoid connector and a ground point, you should see the resistance switching from high to almost nothing with the ECU in test mode.

As above, it sounds as though your solenoid is working, to some extent at least, so spending too much time diagnosing in the area above may not be the best use of your time. Knowing how much boost your engine is developing is important here. Do you have a gauge fitted already? If not, need to either fit one or monitor it via the diagnostic connection.

big_jimbob

Iv not got one but I have got one on order....

How do I monitor it through the diagnostic connection... Iv been trying to work this out...

Jim

Splitpin

Same way as you look at any other data parameter. Standalone ECU monitoring device or a laptop, USB-K Line diagnostic interface plus a select monitor emulator. Click Search and all will be revealed.

big_jimbob

Rite, just been out and had the boost solenoid off the car

blowing in either pipe, end and bottom I can't get any air through the thing! This is all with the green plugs connected and obviously ignition on and plug on to the solenoid...

Sounds to me like its buggered!! it should surely open up!

Jim

big_jimbob

Iv been looking through the search but it all seems hit and miss....

could you give me specifics on laptop cable and software please mate.

Jim

scoobyboothy

iTrader: (1)

try reading this thread

https://www.scoobynet.com/general-te...y-netbook.html

for the cable,

I use romraider for logging, and ecu explorer for fault code reading.

you can log with ecu explorer, but i find romraider easier to monitor as you can have a dash style monitoring interface.

big_jimbob

Rite well iv been and picked up a known working boost solenoid....

Still got the problem!

Iv also had the fault codes read and there were none!!

Im getting really frustrated with this and fed up!

Jim

Splitpin

As I've already said, buy yourself a boost gauge or, (better and more versatile) sort yourself out with some data acquisition kit. You will only find fault codes stored if the check engine light has come on. The check engine light only comes on if something is running sufficiently outside its normal parameters to set its error state.

The reverse of that is that you can have a component acting up (or something acting out of spec) but not sufficiently far enough out to cause an error.

You're getting frustrated and fed up because you don't know what's going on and are stabbing at things that may or may not be the cause of the problem. That approach requires a degree of good luck - and seeing as your luck doesn't seem to be in, you need to either give yourself the ability to find out what it's doing (and so move forward with the benefit of knowledge), or get it looked at by someone who can diagnose the problem for you.

big_jimbob

Rite, iv had a couple of beers and calmed down.. lol

Am I right in thinking I can use one of these cables?

http://cgi.ebay.co.uk/VAG-USB-DIAGNO...item4ced5b44c6

And the ROMRAIDER software to see what my engine and sensors are doing?

Where can I get the software from?

Jim

scoobyboothy

iTrader: (1)

romraider here

http://www.romraider.com/RomRaider/RomRaider

ecuexplorer here

http://code.google.com/p/ecuexplorer/downloads/list

big_jimbob

Is that the right cable?

Jim

scoobyboothy

iTrader: (1)

this is the one i bought

http://www.gendan.co.uk/product_VAGUSB.html

that one on ebay looks the same.