Hi all, I apologise if this is in the wrong section but was after a speedy reply really..

I bought my first Scoob (a 95 JDM WRX) a couple of weeks ago, and I love it, but I have a bit of a problem. At first I thought it was boosting at 1.0 bar but I didnt pay much attention to the boost gauge, its actually in PSI not bar so I misread it, it's only at 10 PSI (0.6 bar).

Anyway, Ive done a little bit of reading up on here and from what Ive read it should be boosting at around 0.9 bar? The car has a 3 port solenoid fitted, and he told me it has been remapped, but I have no proof of this. If it hasnt been mapped, what will the 3 port solenoid cause it to do wrong?

I found a diagram to see if it had been piped up wrong, but it all seems to be piped correctly, but, I cant find a restrictor pill where I think it should be? The top port on the solenoid has a pipe going straight to the 1st vacuum on the turbo, with a reducer halfway along, but no pill? The side exit port on the solenoid goes straight to the actuator, and the botton port goes to the intake just after the MAF.. This is all correct except the missing pill isnt it?

So Im a bit confused and my question really is with it only boosting at 10 PSI, is this likely to be due to the pill missing or should it have a 2 port solenoid? I mean say somebody had fitted a 3 port solenoid but not had the car mapped, what effect would this have? And what effect does a missing pill have?

The car runs sweet as a nut, starts first time and ticks over like a brand new car, but it only boosts at 10 psi. The only other problem is the check engine light is on sometimes, it seems to be more when the car is cold but occasionally it comes and goes when warm too. It still runs sweet when its on, but boosts even less I think? (not 100% sure as drive the car very gently when it is on).

Tried to give as much info as I can, appreciate any help regarding what to do next.

Many thanks!
Steve.

 

I dont think the 3 port uses a restrictor pill. My guess is the 3 port has been fitted and not been remapped and the ecu is in some sort of limp mode to save the engine from killing itself. I also think the WRX should have had the 2 port as standard but could be wrong? Any other mods fitted? Air filter, Exhaust down pipe? or back box?

 

Do a search on here on how to do a ecu check.
You need to push two plugs together but can't for the life of me remember.

 

http://www.scoobypedia.co.uk/index.p...ledge/ECUReset
http://www.scoobypedia.co.uk/index.p...eadingECUCodes

 

Yeah I think it is supposed to have a 2 port as standard, but thats what I was wondering, whether you do away with the pill when fitting a 3 port.. Other mods (that I know of) are Apexi air filter, fmic hard piped, cat back stainless (standard up pipes), boost gauge (feed taken from a different vacuum pipe), bailey dump valve, turbo timer.. Apparenyly it has a walbro fuel pump but not sure, is there a way of finding out? Looking under back seat or something? There is also a metal blanking plug on the intake pipe, not 100% sure what it blanks off?

I havent got round to doing a code check yet, thought Id ask about this pill/solenoid first..

Thanks

 

If the dump valve is a vent to atmosphere get rid and put a stock recirc one back on. Does the ECU look like it may have been played about with? Any non standard stickers on etc..

 

Just had a quick look at the ECU, no stickers or anything apart from the standard Z4 one, only thing a bit strange looking is one of the wires coming out of the ECU has had another wired tapped into it which doesn't go anywhere, it's just blanked off/taped up?

He also said it had a TD05 aswell, but Im not sure I believe him, standard is TD04 isn't it? Is there any way to tell? Got all intake pipes out of way but cant see any numbers..

Thanks again.

 

Oh and the dump valve.. I dont know if it vents to atmosphere? It has a pipe about an inch diameter on one end joining it to boost pipe just before inlet, some holes in the side of the dump valve with like a diaghram in, and a vac pipe on the other end going to the top of the inlet manifold.. So Im not sure? Does it make a difference?

 

Does the dump valve make the woosh noise??

 

Can you take the cover off the ecu? It may have a daughterboard fitted. The blanked plate could be a lambda sensor has been removed.

 

Yeah a very loud pitch metallic sort of noise..

Just had a good look at the turbo, it DOES say TD05 on it, so it has had a different turbo too? He said it has had an STi engine, but Im not convinced, think its just had a different turbo, they are supposed to be a TD04 arent they?

 

Im not sure if you take the ECU apart, have put kick panel etc back now, dont think Id feel confident dismantling the ECU?

 

Wouldn't a 95 come with a 3 port as standard? I thought it was the later cars that switched to 2 port?

 

Can you take a pic of the engine?

 

95 wrx came with 3 port standard and does have a restrictor pill standard 0.6 sounds like limp mode you need to read error codes if check engine is on do a search for the code list and how to do it it's dead easy I have a 95 wrx bought it standard 6 years ago and yeah should boost to 0.9 with the z4 ecu which is also standard on the 95

 

I could take a pic of engine but Im on my phone so cant upload it.. Is there any obvious differences I could look for? Think it has grey injectors, thought I read somewhere that STi's had yellow injectors? I may be wrong? Or could that be the problem that it needs bigger injectors due to the mods? Or am I completely miles away?

All this stuff is new to me, Im used to pintos and crossflows, carbs and distributors lol..

 

Ok thanks for that info, will do that next, so it should have a restrictor pill.. Thats interesting, well Ive got starter off at the mo (packed up yesterday) so will read the codes when thats back together.. Is it worth me going and getting a pill and trying that as I have all the intake off at the moment.. If so, is there different sizes? What do I get?

Thanks for all the help, Steve.

 

Found this posted by Scott.T on here back in 2009

Pre 96 Pill is 2mm and goes in bottom pipe of 3-port solenoid.
97> Pill is in pipe btween turbo nipple and t-piece, which goes to actuator and boost control solenoid. This uses the 2-port solenoid.

The 2 locations have the oposite effect.

On a Pre96 removable of the restrcitor or a larger restrictor will cause boost spike, or slight increase in boost. Becomes a probem if decatted as ECU will try to compensate and somestime induce fuel-cut.

On 97> the smaller the restrictor the greater the boost. If you get boost spikes just open up the restrictor by 0.05mm at a time.


Standard Pill in a 97-99 is 1mm,STi is 0.9mm I think.

I think the later WRX 2001> had 1.1mm or maybe even 1.2mm.
I know that 2001> WRX 99% of the time need the restrictor reducing to 1mm in order to map to 1.2bar. If the restrictor isn't changes, no matter how you increase the Boost control duty it still struggles to get above 1.1bar.

 

Ah thanks for posting that david, Ive just looked in the bottom pipe and it DOES have a little pill in there.. Hmm.. So next thing then is put it all back together and check codes.. Does it sound like its edging towards needing a map? If so what sort of money is that going to cost?

Thanks, will read codes at some point today

 

Right, Ive put it all back together now (starter works hooray), and I did the fault code check..
Came up with one code;

NO. 22 - KNOCK SENSOR

This worries me now because knock isn't good.. Is it?

So any suggestions where I go from here? Could it be due to needing a remap? Or am I getting carried away and it's something else?

We've established it is supposed to have a 3 port solenoid and the restrictor pill is where it should be, and the list of mods are above but I don't know if it has been mapped..

Thanks again for the help!

 

How old is the fuel in the tank and what fuel have you put in it? Do you not have any paperwork with it at all regards to any of the mods that have been done.

 

I know it sounds really crazy mate, but check that the pill is correctly aligned in the pipe....I fitted new pipes and pill wasnt inserted correctly and my boost was good, then bad, then good etc

Also, if engine light intermitant I dont think ecu in limp mode yet, normally light stays on. Have you checked all the pipes while its running for leaks and that they are all connected where they should be?

Hopefully, its a simple mix up somewhere

 

Knock sensor is very common buddy and a easy little fix. Just replace it with a new one.

 

Change the title of the thread was gonna offer you a spare pill but took me a page to find out this isn't your problem

 

Just change knock sensor dude and reset ecu to clear the codes if car is detecting knock or dodgy sensor pretty sure it pulls boost to save the engine so that could be it just a theory

 

The fuel is fresh, Ive put £50 worth of Shell V Power in since I bought it, has about 1/4 tank left, and only paperwork I have is a couple of MOTs/services/wheels/tyres.. The car has launch motorsport stickers under the bonnet/drivers door step so I sent them an email to see if they had done any work on her but I got no reply..
The lad I got it off had only had it a few days and didnt know alot about it, hes a swapzaholic lol..

Where the pipe comes out the bottom of the solenoid, the pill looks like its right where the first bend is in the pipe?
I have had pretty much all the vac pipes off today and theyre all fine, can't hear any sucking or anything when engine is running, plus it seems to tick over/run too sweet to have an air leak, and when it comes on boost it doesn't fluctuate or anything like its losing pressure, just a steady 10 psi.. Ive checked diagrams for the piping to and from the solenoid and they all seem to go where they should..

Yeah I don't mind replacing it if it's at fault, but like I say the light isn't on permanently and even when the light is off it still only boosts at 10 psi? If the knock sensor is faulty, causing the car to go into limp mode, would the light not be on permanently if that makes sense?

And thanks for the tip, will change title now

Thanks again for all the help!

 

If its throwing knock sensor code up at all then replace it. It's a very easy and pretty cheap fix.
Swap it out, reset ecu and go from there.

 

Okay Il just do that then, suppose it would be daft not to.. Just a bit confused why it never boosts past 10 psi yet the light isn't always on?

Thanks

 

Forget about boost for now chap, get the important bits done first and then go from there.
A new knock sensor and reset may cure the boost problem anyway.

 

No probs, thanks for the help!