Jumpy/Laggy Secondary + CEL

[swanson-07]

Hey,

I have the issue of laggy/Jummpy Det feel at 4500rpm

In the weekend I had a mechanic replace the turbo intake hose as it was pretty F#$%'D thought that was the issue, Also when I plug in under the dash I get a flashing CEL????

PS Factory EVERYTHING NO MODS that would cause DET,

replaced so far....

Knock Sensor

Air Flow Meter

Sparks

Coils

Turbo intake Hose

Few Vacuum lines

Price is starting to add up with no luck yet

Its a 2000 Legacy B4 = my worst nightmare so far!

[Rosssub]

What CEL/fault code are you getting?

[hijacka]

 Rosssub said:

What CEL/fault code are you getting?

I'm thinking if its a coded flash the op would have said what number etc so im going to assume its normal flash thats being veiwed

V.O.D is around 4500 so perhaps thats the cause.. a problem thats not a problem lol.

[94 Leone]

Maybe when it hits VOD; it's still fuelling at the same rate for when it was boosting; so it overfuels causing Det at VOD; see marky's threads about fine tuning VOD to bare minimum.

Hose 10 mod

If you'd like to try see if it is an issue of the sequential system you could try the Parallel setup

Edited May 13, 2014 by 94 Leone

[swanson-07]

Im under the impression that the Rev C legacy had no VOD or Very Tiny amount,

Went for a drive last night, No Det, No Lag, But feels like secondary isnt even there, primary is amazing but runs out off juice

[hijacka]

They all have the dreaded vod, Might wana check condition of secondary turbo

[swanson-07]

Could a wrong vac line connected or something cause this?

Also previous owner removed a restrictor pill wondering if primary turbo is boosting more then second so its not noticeable that its boosting at all? If that makes any sense

[94 Leone]

If your secondary ends up being ****ed; I have a good condition VF27 here.

Check your Vacuum lines with reference to that diagram.

I also HIGHLY recommend reading This thread.

Edited May 14, 2014 by 94 Leone

[swanson-07]

Done the hose 10 mod, Got my 15psi back ,

only issue is feels like a lag at 3500rpm gets over it and same again at 4500rpm then still no Secondary?

Thinking of this cheap parallel setup?, http://clubsub.org.nz/forum/showthread.php?32559-Idiots-guide-to-converting-your-legacy-to-parallel

Yes i know that id get EPIC lag but hey ive got no power in high end coz secondary isnt kicking in at all, hoping that this mod will make a miracle happen and make it work

;( i just want to give up

[Rosssub]

Put it into diagnostic mode and make sure that the ECV and IACV are working properly. Did you have any CEL fault codes or was it just a constant flash?

[94 Leone]

Check oil feed to your secondary turbo; make sure it isn't blocked up. Give parallel a try, see how much you like it.

If you can do a test run in normal sequential TT mode(record it if it helps you remember) through the rev ranges.

Then again in parallel mode compare it if you can. Do you notice any extra noise when it goes into 'secondary' mode? like possible damaged turbo?

[swanson-07]

No CEL codes, just constant flashing but still no boost lol, Any one want to quote me to single turbo it? i'm in Picton and can provide accommodation haha

Would the Purge Control Solenoid cause this issue?

[swanson-07]

It looses boost at 4500rpm just pulls hard until then it drops a few psi and holds that right to red line its like its just on primary nothing more, you can feel like .5seconds of secondary then nothing which is the jumpy I was saying earlier

[swanson-07]

Would replacing the exhaust fix the issue?

Read a few years ago a guys username "Mattapo" had collasaped exhaust causing a similar issue, or even the cat causing the issue?

[94 Leone]

Might be; either way it's worthwhile to take them out anyway.

[Marky]

Purge solenoid won't be the cause of it

If you're feeling like testing things just unbolt the exhaust at the Y pipe, see if problem persists (that would be blocked second cat or muffler) Might be a bit loud mind you but you'll hear the switchover, it's very blatant.

Lock it in parallel, see how that goes.

It might be the secondary BOV being stuck open too, just a thought? Could also be the ECV being adjusted real far towards closed, I found if you wind it right in it does restrict flow to the secondary a bit but not enough that it makes it feel busted

Has it always been this way or just started? Bear in mind they aren't super duper fast

[swanson-07]

In 5th gear at 3000rpm it shakes, primary is boosting but secondary prespool just doesn't feel right. Im at the stage of putting in a wrx motor and setting the twin turbo alight!! GRRRR so angry, Anyone in marlborough or want to come have a look give me a quote and fix the damn thing.

dont think putting it into parallel will do stuff all cos secondary wont work atm? it kicks in and out doesn't stay boosting

[Rosssub]

 Rosssub said:

Put it into diagnostic mode and make sure that the ECV and IACV are working properly.

Also do you know which restrictor pill was removed?

[94 Leone]

What it will do though is allow exhaust gases to the secondary without restricion so pressure will rise accordingly. If you investigate your secondary, and find it to be fudged.

I have one thats in okay condition; I sold the primary to Marc a few years back and was in good condition.

[Marky]

What

If you have a problem at 3000rpm in 5th it's not a problem with the turbo, it sounds more air flow related (like leaking BOV, dud AFM sort of thing)

Trial by replacement is not the way to sort this, you need to rule things out before just buying new bits. I've got a query why the mechanic has replaced the intake pipe - was it split? has part of it been eaten by the motor? See if someone can do a pressure test on the intake system

Like I asked, has this problem started by itself or is it after something got played with?

The TT system isn't very complicated, if you blank off parts of it you can rule things out (for example if the secondary BOV is leaking, you can block it... if you think the primary one is, you can block it) - if you lock it in parallel, then you are ruling out a -mechanical- problem and narrowing it down. No point chasing air flow meters etc if it turns out the turbo is seized, ditto for converting it to single turbo just because someone hasn't clamped a hose or something stupid

[94 Leone]

I'll lend a hand when I have some free time that suits both of us; your fiance facebooked me(I was the one going to swap cars; then well my HG blew-again)I have a VF27 we can trial to see if that's caused issues: but at the same time will check oil feeds to make sure they aren't gunked up. If you get the silicone intercooler hoses we can put them on then aswell; that'll remove a boost leak post turbo as the issue.

[94 Leone]

For those wondering it ended up being the secondary bypass valve. It has been fixed and Swanson appears to be over the moon, he hasn't tried the ECV line restrictor yet. But it ended up him not having to fork out a trip over here to motueka. so relatively successful

[Marky]

Aww yiss

[swanson-07]

but now it goes i have nothing to work on.....

Im bored

any mods like hose 10 that has no risk but improves vehicle. Defo looking into the silicone intercooler to turbo hose. what else is there?

[Marky]

Front mount

VF27 primary swap

Boost control of some sort

Intake pipe

Saving your money and doing a single swap / getting a wrx instead