cant get past 10psi

[xxXSnOw]

Hey guys.

have a slight problem....iv done alot of google searching and i mean alot... in regards to a wrx v7 not getting past 10 psi.

when in 3rd/4th foot flat i reach a max boost of 10 psi from what iv read everywhere i should be reaching around the 14 mark?

i have tried reseting the ecu,iv checked every hose and clamp making sure they are tight and non split i do have a pill restrictor in there which i assume works havnt taken it out as of yet

and the engine is completly stock.

any one had this problem which they fixed or know what might be casuing this?

Thanks in advance guys.

Dan

[R8TD_R]

just get a boost controller bro much easier no head ache

[gazzy2000]

what ever you do, get it running properly with the stock boost solenoid setup before you run any A/M boost controllers.

The ECU cud be in safe mode i.e. it stops controlling the Boost noid, limiting the boost to wastegate pressure (around 10 PSI) so no damage is done to the engine, the ECU does this if there is a problem i.e. major Detonation or whatever (make sure you are running 98 octane )

Fitting an after market (AM) boost noid can and will up the boost as required but can also do more harm than good if the ECU is in safe mode for whatever reason i.e. fitting an AM noid only masks the problem.

I take it you run 98 octane?

After a reset does it boost higher for a start then drop back to 10 PSI after some boost driving?

[Pappu1]

Wat area u from

Yea Wrx v7 should get to abt 14

Has this always been happening or just started

Have u got a bov on car

Do u hear any irregular noises by any chance

Dos the car pull well til 10psi or struggles to even get there

Wat host u get in top gear

[B_Man]

Similar thing happened with a friends V7 with aftermarket headers, tuner couldnt get it past 14psi, Put factory headers on, and got to 20psi fine.

[xxXSnOw]

yeah i always run 98 octane,starts up exceptionally well no funny noises, drives smooth,has no trouble going through the rev range in all gears, no smoke. boost kicks in and gets to 10 and stays there through the rev range. but thats just it it doesnt go any higher...

yeah from memory it has always been 10 psi the only reason why iv only just asked now was because my mates v8 is hitting 14 so thought mine should be too.

motor is stone stock.

no engine warning lights nothing.

lol im compeltely stumped maybe a faulty solenoid?

how can i check if theres error codes on the ecu?

thanks for you help so far guys.

[gazzy2000]

after checking all hoses & clamps etc this is how i would approach this boost problem, (may not suit some ppl)

if you are ultra ultra careful you can pull all vac hoses off & block them at the wastegate actuator at the turbo and free boost it, i would only do this as a one off test just to prove everything else is OK i.e. no boost leaks and the turbo + components are boosting/working well etc.

This method will let it boost extremely high if you let it and is very dangerous, for gods sake DO NOT hold it at boost for a long time and just do a couple of boosts to around 15 to 18 PSI just to make sure all is well in the turbo and boost department. Listen for boost leaks and noises etc.

If unsure how to do this, DONT DO IT

The next step after a free boost test.. i would wire in a LED light accross the factory boost noid then into the cabin then go for a drive and see if it is actually flashing, if it is that means the ECU is doing it job, if not take it further from there (report back here)

[Guest]

to check codes

http://www.clubsub.org.nz/forum/index.php/topic,67.0.html

-smurff

[Joker]

and sounds like wastegate pressure

on upside fuel bill will be less and you are not loosing tooo much powers

[xxXSnOw]

 gazzy2000 said:

after checking all hoses & clamps etc this is how i would approach this boost problem, (may not suit some ppl)

if you are ultra ultra careful you can pull all vac hoses off & block them at the wastegate actuator at the turbo and free boost it, i would only do this as a one off test just to prove everything else is OK i.e. no boost leaks and the turbo + components are boosting/working well etc.

This method will let it boost extremely high if you let it and is very dangerous, for gods sake DO NOT hold it at boost for a long time and just do a couple of boosts to around 15 to 18 PSI just to make sure all is well in the turbo and boost department. Listen for boost leaks and noises etc.

If unsure how to do this, DONT DO IT

The next step after a free boost test.. i would wire in a LED light accross the factory boost noid then into the cabin then go for a drive and see if it is actually flashing, if it is that means the ECU is doing it job, if not take it further from there (report back here)

ahh i havnt had to do that test in a long time!!

ok so so turbo components are fine went straight past 10 no problem .

Havnt as of yet wired up the noid with a led because iv hit another brickwall.

In the process of removing the required turbo hoses i found that when taking them off they all pretty much broke and snapped and the pil was so brital that too snaped in half.

looks like the hot cold hot cold from the motor over the years has worked its magic.

Question where to from here?

i just rang winger and 70 bucks + 2wweks delivery id rather not.

cheers too Smurf ill look into that a little later

u rekon waste gate preassure so pill/noid? only thigns i can think of that regulate other then the ecu telling it what to do....

P.S i dont want to save fuel!!! hahaha

[gazzy2000]

sort out the new vac hoses (and check all others for that matter) then try it again

EDIT: you free boosted it and it boosts fine ... well everything else must be OK incl turbo etc, sounds like it cud well be the pill n vac hoses etc, fix that sh1t first, you only need a pin hole leak in those vac hoses at the turbo for boost to be effected

should be able to buy all the vac hoses and T joiner etc from a performance shop (or the like) then make it up yourself

[gazzy2000]

just to add... the LED test is a real good one as once you have done it and you know the ECU and wiring is all doing its thing + the plumbing is mint.. you can start suspecting the boost noid itself or maybe a map sensor etc

[xxXSnOw]

 gazzy2000 said:

sort out the new vac hoses (and check all others for that matter) then try it again

Dam near reckon that cud be yr ptoblem, you only need a pin hole leak in those vac hoses at the turbo for boost to be effected

NINJA: oh wait.. you free boosted it and it boosts fine ... still fix that sh1t first

should be able to buy all the vac hoses and T joiner etc from a performance shop (or the like) then make it up yourself

yeah when i originally checked over the hoses they all seemd squishy and soft but all the near the ends were like rock.

Im ganna go get all the hoses tomorrow

in the mean time what can i do in ways of getting another pill? seems mine is toast.

[gazzy2000]

from another post:

Pic of boost solenoid LED wiring

Purchase a LED from Jaycar, its one with wires already wired on it and IIRC it has a built in resistor too. Buy a lenght of twin core (from jaycar too) and extend the LED wires long enought to reach the boost noid from the cabin area, then fit as per instructions below.

(1) boost solenoid

(2) twin core cable going to LED on dash

(3) scotch lock joiners

(4) actual boost solenoid factory plug

Unplug the factory plug, turn key on and find which one is 12v, the other one will be the ECU switching wiring which turns the earth on and off to the noid thus controlling boost.

Positive of the LED (red) goes to 12v and black to the other wire (ECU switching wire).

I have to caution its not recommended to use a normal test light to probe the plug wires as damage can occur to the ECU. its just a caution so you cant pin anything on me.

[gazzy2000]

 xxXSnOw']

[quote name='gazzy2000 said:

sort out the new vac hoses (and check all others for that matter) then try it again

Dam near reckon that cud be yr ptoblem, you only need a pin hole leak in those vac hoses at the turbo for boost to be effected

NINJA: oh wait.. you free boosted it and it boosts fine ... still fix that sh1t first

should be able to buy all the vac hoses and T joiner etc from a performance shop (or the like) then make it up yourself

/quote]

in the mean time what can i do in ways of getting another pill? seems mine is toast.

the wreckers, but yud wanna get the right one for a v7

[Pappu1]

 gazzy2000']

[quote name='gazzy2000 said:

sort out the new vac hoses (and check all others for that matter) then try it again

Dam near reckon that cud be yr ptoblem, you only need a pin hole leak in those vac hoses at the turbo for boost to be effected

NINJA: oh wait.. you free boosted it and it boosts fine ... still fix that sh1t first

should be able to buy all the vac hoses and T joiner etc from a performance shop (or the like) then make it up yourself

/quote]

in the mean time what can i do in ways of getting another pill? seems mine is toast.

the wreckers, but yud wanna get the right one for a v7

correcto

need to get the right size

what area u in?

another option is that since boost builds fine, just put a tap on it and be done

easy option that lol

set tap to 15psi and enjoy (assuming stock td04 turbo)

costs are minimal too

if u wana use the factory setup then u need to get the right size pill or get the boost controller reprogrammed for the new pill

(assunimg solenoid is fine)

[gazzy2000]

hur is a pic of the LED i use from Jaycar (IF you end up needing to get one), does have resistor wired already for you, cost = $4

I reckon once you do yr vac hoses n pill youll be right though 8)

[Pappu1]

so to confirm - when led is lit the noid is bleeding boost ya?

[gazzy2000]

 pappu said:

so to confirm - when led is lit the noid is bleeding boost ya?

well its being 'dutied' (switched on or off) so ya

Reason i say 'dutied' as oposed to 'bleeding boost' is because 'dutied' refers more to the electrical function and 'bleeding off' is the mechanical function - just to be a douche .

Its the duty cycle / frequency (how fast the ECU switches the boost noid on and off) that controlls the overall system boost, so the mechanical function of that is that the pressure in those vac hoses is allowed to build up then bleed off opening and closing the wastegate via the actuator thus controlling system boost.

EDIT: but either way if all is well and the ECU is doing its thing, you should see a flashing LED, if not it will more than likely be in safe mode if the wiring is crook.

[xxXSnOw]

ok time to update,

Replaced all turbo hoses used hose clips to secure to make sure nothing is going to leak went for a drive. and still hiting 10 psi in 4th gear before its starts dropping off.

So im thinking ill firstly check to see if theres any ecu faults (as it doesnt require me to buy/change anyhting.)

so in a v7 where is the ecu located?

And if for example it comes back with no wrong codes where the heck to next?

Also im located new lyn/blockhouse bay ways so maybe if this fails some1 might be able to have a look....

cheers for all your help so far guys/

[gazzy2000]

 xxXSnOw said:

ok time to update,

Replaced all turbo hoses used hose clips to secure to make sure nothing is going to leak went for a drive. and still hiting 10 psi in 4th gear before its starts dropping off.

So im thinking ill firstly check to see if theres any ecu faults (as it doesnt require me to buy/change anyhting.)

so in a v7 where is the ecu located?

And if for example it comes back with no wrong codes where the heck to next?

Also im located new lyn/blockhouse bay ways so maybe if this fails some1 might be able to have a look....

cheers for all your help so far guys/

bugga, oh well... at least now you know that everything is tight both from the free boost test and having replaced the vac hoses etc at the turbo.

Yea, so checking codes... on a v7 not sure if the v7's are like the GF and GCs i.e. plug in the two plugs under the steering wheel etc, someone here will know that. But yea check those first (i dont think you will need access to the ECU itself, am unsure for the v7s though sorry)

If it comes back with no wrong codes then we can do the LED test, when i had bad detonation with my car i had no codes at all but was still in safe mode only boosting 10 PSI and the only way to see the safe mode (with out fancy equipment) is using the LED to see if the ECU was controlling the boost noid i.e. it was flashing

[Pappu1]

Need to plug in a diagnostic reader in the ecu port to get codes in v7

I can do that for u if u want

Did u check to see if u have a pill in the hose off the turbo nipple to the wastegate t piece

[gazzy2000]

 pappu said:

Need to plug in a diagnostic reader in the ecu port to get codes in v7

I can do that for u if u want

Did u check to see if u have a pill in the hose off the turbo nipple to the wastegate t piece

yea right, well a proper subaru diagnostic reader should say if its in safe mode or not too (hopefully)

also i was thinking.... a crook and/or temperamental knock sensor cud be the culprate too, the diagnostic codes shall reveal all

[xxXSnOw]

 pappu said:

Need to plug in a diagnostic reader in the ecu port to get codes in v7

I can do that for u if u want

Did u check to see if u have a pill in the hose off the turbo nipple to the wastegate t piece

mate that would be excellent if you could....Atleast that will reveal anything that could be the culperate.What sorta day/time?

yeah i made sure the pill is on the turbo side b4 the T

just an anoying problem

[Pappu1]

Usually shows lot of knock if it's sensor issue

Ecu may not be registering it as a faulty sensor as sensor could be giving a reading but just a false one

Anyway yea a diagnostic will show and also can reset the ecu to test out if thaolenoid or pill issue

Tomorrow shod be sweet wil pm u my number