Hey all, I had a thread yesterday about the problem Im having with my Scoob, but it all got a bit confusing, so heres a bit of an update:

The car is a 95 JDM WRX. I bought the car 2 weeks ago and the CEL has been on and off intermittently, but the car will only boost at about 10/11 psi.

The car has a TD05, Bailey DV, 3 port boost solenoid, Apexi cone filter, cat back stainless, hard piped fmic, and so Im told a Walbro FP (but haven't checked this).

Yesterday I checked a few diagrams on the net and made sure all the piping to the boost solenoid etc is piped correctly, everything is fine, no splits, leaks etc. The restrictor pill is present, and I carb cleaned the MAF and the boost solenoid.

Next I checked the flash codes, and found one code. No. 22 - knock sensor. So today, I got a knock sensor, fitted it, did an ECU reset, and hoorah, the CEL is now out! So I let the car get nice and warm (as always), took it for a drive, and it is still only boosting at about 11 psi? The engine starts straight away, runs sweet as a nut, holds boost perfectly, but wil only boost at 11 psi.

The fella I got the car off had only had it a couple of days (took it as a PX for something) and I have hardly any history, so I dont know if it has been mapped since someone fitted the turbo etc.. (theyre supposed to be a TD04 arent they? Please correct me if Im wrong).

So, is that my next job do you think? Does it sound like it needs mapping or would it run like crap or something if that was the case?

I look forward to your advice

Also, if you think thats what it needs, would it be worth swapping for bigger injectors or anything like that beforehand?

Many thanks, Steve.

To be fair mate your boost doesn't sound too far out. Lift your foot plate under the carpet in passengers side hey presto theres your ECU see what is on there I expect something like U8 OR 7D then do a search on here for the boost target for that ECU it may be thats the target for that ECU or the boost gage is slightly out, if memory serves me right they only boost to 11-12 psi as standard.

The td05 is the correct turbo as well on that age of JDM.

or ur DV is on its way out and not holding boost ?

The ECU says Z4 on it, Im sure I read on another thread that that ECU should boost at about 14 psi standard?

Its not that its not fast enough, I just want to know that the car is right, ie. Not risking damaging anything? Im nee to this, Im used to pintos and crossflows, and I see threads on here people saying 'dont boost it until its mapped etc. otherwise it could damage it', thats what my worry is

Thanks for the info on the turbo aswell, was under the impression it should have a TD04

And how would I know if the DV is on its way out? How do I check that bud?

Thanks again Like I say, not worried about the speed, just worried about damaging something

bailey dv could be the prob. mine had 1 when i bought it and it was sticking open and losing boost, but you would be able to hear it dumping the boost pressure for sure. baileys dv,s have a name for being problematic. i changed to a forge one and it cured it straight away.

So is there a quick way to find out if its knackered then? Or do I just have to try a different one and see what happens?

I don't really know alot about DV's but it sounds OK to me? Makes a very loud metallic sort of woosh when you back off the throttle?

Thanks

Ditch the dumpvalve, block off the pipes that were connected to it, with the cone filter it will sound ace. Z4 should boost about 14psi but as mentioned your boost gauge may be out,in theory it should be remapped with the mods you have but the z4 was one of the better ons s it may be ok get it on the rollers and have the fueling checked.

This is what I would do.....

Remove that dump valve and place it in the wheelie bin. Refit the standard re-circ valve.

I'm pretty sure your car should be making 0.9 bar of boost which equates to 13 psi so your not far out and it's possible you DV is on its way and causing this slight loss.
I'd also be getting the car over for a check up at a dyno.

Ok thanks for all the help! I just basically wanted to make sure it was safe to drive

Will definitely get it mapped as soon as I can afford it, but (I suppose this probably gets asked 1000s of times), should I change anything before mapping? Injectors, decat, anything like that? Or is it not worth it?

Thankyou Will try doing away with the DV tomorrow!

Hey, right yesterday I removed the DV and blanked off the pipes, I took it for a spin and it seemed to take longer to spool up and was still only at 11 psi. So I refitted the DV, obviously not that..

Today I thought Id try it without the restrictor pill.. So I removed the pipe with it in and fitted another pipe temporarily, took it for a little run and it boosted at about 13 psi, and seemed to pull really well..

The car has a TD05 and 3 port as standard, and the pill is in the pipe coming from the bottom of the boost solenoid..

So, should I leave it out or put it back? Will it do any damage being out?
And when I get round to having the car mapped, should I have it mapped with or without the pill?

Many thanks in advance

are you sure it is a proper z4 ecu not another one with a z4 casing. there are some other numbers on the ecu somewhere that should match up with what ia on the case

Why would somebody do that though bud?

you`d be supprised what people sell that are supposed to be the genuine item

My understanding (and I'm sure someone can confirm) is that the import wrx for that year come with the td05. But boost is around 1bar as they had more power then the uk counterparts. 1bar is approx 14.51psi. 11psi is only around 0.8-0.85bar.

You've got several mods on the car and it doesn't seem to be mapped. Take it to a specialists who will look over it for you. I'd never run a fmic and other supporting mods without a map and it could explain your issues.

As Andy says above,.
Also get rid of rthat Bailey d/v and go back to a recirc type, BEFORE it's mapped

Failure to take note of Andy will result in the engine going bang, sooner or later.

Failure to take note of me will mark you as a chav.

Boost cuts and boost targets for all Jdm early ECU'S
Model / VariantFuel CutBoost Target (WRX/STi Saloon ECU’s 2C, U8, W6, W9 Fuelcut 14.57 psi Target Boost 11.47psi held to redline)(WRX (1995/96) ECU Z4 Boost cut 15.65 psi Boost Target 12.71psi, dropping to 11.78psi @ 6600rpm)

What size was the restrictor pill that was fitted ? ID should be 2mm IIRC. If someone has fitted a later one it will be smaller and a problem

I'd only remove the DV when having the car mapped runs tidy without if set up properly

Thanks for that all, I will get it mapped as soon as money allows Just unsure as to which route to go down as Ive never had a car mapped Plus I guess it would make sense to invest in some yellows and a decat before mapping..

Had the cover off the ECU kick plate out again today, judging by the screws hold the ECU casing together, it has never been messed with..

Thanks for posting that Tim, thought the boost target was higher than that, where did you find that? If it's correct then Im not far off

And the DV, yeah, Im not a massive fan myself, but somebody told me it helps? If it hasnt got it, does the air not try going back through the turbo? Surely that isn't healthy?

Thanks for the replies

Oh and the pill, Im not sure sizewise, suppose itll be a standard 2mm one, looks standard lol..