OK so fitted a boost gauge today I'm hoping I got the right pipe (see pic of pipes) lol I used the one coming from the inlet manifold to the little solenoid near the turbo on my 93 wrx it's now showing on idle -.9 and on full throttle 0.5 bar is this standard I'm running a td05 and would like to up the boost a bit is 1 bar too much for that turbo and standard internals I'm not sure if it's closed or open deck if that matters sorry I'm a learner at best when it comes to mechanics lol but getting there lol also I'm using a pillar pod for the gauge and where the line is run its a lititle bit squished but not by much will this affect the reading

 

Looks like you have the gauge installed in the correct place,this is a good guide I used on my old classic.
http://www.scoobymods.co.uk/boostg01.htm

From what I can see you have a cone filter and what looks like a cheap dump valve,I would suggest going back to the standard airbox with performance panel filter,going back to oem recirc valve.
You should be hitting around 1bar as standard,I'm guessing that the restrictor pill had been removed? This will cause overboosting and put the cars boost into limp/safety mode which is 0.5bar actuator pressure.
Check the vac lines are all ok and that the one on the bottom port of your 3 port bcs has the pill in place.

You can use the cars self diagnostic for looking for any error codes and to reset the ecu.

 

Oh and just to say any squished pipes are not good.

 

If you look behind the alternator there is on the later classics a blanked off with a rubber bung take off point which is ok to use.

 

It's not a later classic,it's a series 1.
Should work ok where it's plumbed in,the 'squished pipe' is not good tho.
And if it's only hitting 0.5bar this indicates a problem,ie un mapped parts,no restrictor pill,bad pipework(including squished!)
What other mods have you got on there? Full decat by any chance?

 

OK so I'll start with the mods kakimotor 3"exhaust decat stainless steel headers td05 turbo not sure what g it is walbro 255lph fuel pump obviously that stupid filter and bov that I'm not keen on as far as I'm aware it must have some sort of daughter board or chip as when I bought the car it came with dyno printout at 310bhp from a couple weeks prior to me buying it and it still has the standard z4 ecu as far as I know the injectors are standard but will be upgrading them end of month I did the flash codes and it came up code 22 knock sensor so reset the ecu and took it for a drive still same boost level but was getting too dark to check fault codes again for knock sensor fault would that restrict the boost? I'm going to invest in a small peice of metal piping I can run the tube through at the problem area at the dash to stop the pipe getting nipped. I'm eventually aiming for 400bhp so just now I'm just trying to get it running sweet I have a block that I'm saving to get forged and hoping to replace the entire drive train for a 6 speed I already have a fmic with a good bov on it sitting around I was going to wait till I needed it but may aswell fit it now as the tmic has seen better days so no point going back to a recirc but I am going to fit the standard airbox back on the I hate hearing the turbo sucking like mad. What pipe has the restrict or in it as I can't seem to feel it in any of the pipes there is a small plastic join peice that seems to step down in size on the pipe running from turbo housing to the little unit to the left of the turbo sorry I'm not sure what it's called lol

 

It is possible that it had a MBC fitted at some point? The restrictor pill should be in the bottom pipe of the 3 port bcs and would have been removed if someone did fit a MBC.
I would of though it is possible to get the car running at 310bhp with the boost increased with the MBC but it's not a safe way to up the power.
So the ECU might have a generic chip like polar performance chip,or some other generic thing like that,it's also possible (if you're lucky) it has a mappable ESL daughter board in there and has been mapped to suit the decat and other mods on there?

If fitting a FMIC you will need to loose the oem airbox anyway.
What ever you do you will need a mappable ECU. There are a few options but all depends on how much you want to spend on the ECU side of things?( I choose ESL)
By the sound of things,forged build,6 speed ect ect you have deep pockets

Hope it all goes well for you mate,keep us posted to how you get on.

And yes knock sensor fault can cause limp mode/low boost as can most of the sensors if faulty.

If you have no restrictor pill in there then this can also cause this problem.

 

Here you go,had this in my bookmarks.
http://www.scoobypedia.co.uk/index.p...tRelatedIssues

 

Not so much deep pockets more plenty time lol don't intend on selling it so it will be a slow progress over the next few years to make it safe to support that power but just now I'm focusing on sorting out the issues with it. So is it better to fit the pill or a boost controller? If i went for a controller it's not something I'd be playing with I'd leave that to a good tuner to set up. What's the best filter to go with in conjunction with a fmic

 

RCM,K&N,blitz are a few of the good filters,I would avoid HKS mushroom,Perrin foam. Just have a search around on here,there's loads of good info on here.
You could fit a Dawes device or decent MBC and keep it on the lowest setting but personally I wouldn't touch em,best bet is to fit a pill,some people fit welding tips which do the job of a pill ok but I can't say from personal experience,again there is good info on here about this.

Best thing to do would be get the car back to standard as much as you can then build from there.
Only problem is you have a full decat and other mods on there that need mapping in,until you find out what you have inside that ECU best thing is to stay off boost,your AFR's might be way off and the car could be detting it's **** off.

 

So what's the best way to check for a definitive answer can I just unplug the ecu fake the screws of and check or is there another way I've been told it's suspected to have an esl but I'm not taking that as gospel until I have seen it for myself

 

Yes only way to tell is open the ECU.
Unless you know someone with an ESL cable to plug in for you and check that way,I have one but you're a bit far from me in I think(Aberdeen ? )
Easy job tho to take the ECU off and look inside

 

Yeah Aberdeen lol. OK can I do it with the ecu in situ or is it best to unplug and remove it. Also assume it's best to have the battery disconnected

 

Yeh I would say unplug the battery,I've never tried opening up the ECU with the plugs still connected but you will have to unbolt it from its mounts I would have thought so no biggie if you have to take out the 4 plugs and unscrew the lid to see what you have in there.

 

So no esl board so that's where my problem will be but a pal has an apexi power fc kicking about so hopefully get that and get it mapped end of month but if it's 310bhp with it can expect any gains from it or will it just run better and smoother

 

Find a rolling road and get it checked, a z4 should hit 0.9 bar anyway,
But not close to 310 bhp, sorry.

 

No ESL but it does have what looks to be a generic eprom chip in there so this would explain why it did/does have 310bhp.
It should be boosting more than 0.5bar to get you to that figure,hence why you should have the restrictor pill in there.
Best to get it checked to see if your not detting,running lean ect

 

Jdm stig I was sure last time I was looking at the ecu it was a z4 but it's actually a u8 not sure what the difference is. Ossett 2k2 after I had the ecu out and back in again it's boosting to .7 at peek not sure if that's from the reset but it seems to be back at .5 again but never got much chance to put it through its paces or even get full throttle for more than a couple seconds

 

Is a generic Epsom chip mappable

 

Eprom chip not mappable as such,you can write onto an eprom with the right kit but just not worth the hassle when you can but ESL for under £300.
That's if your mapping yourself,if you want it fitting and mapping you will be looking closer to £600.
Sounds like the cars not happy so as soon as the ECU is seeing the fault it's putting your boost into safety mode@ 0.5bar wastegate pressure. Just get a restrictor pill if it's missing otherwise it will never be right even when mapped.