Boosting problem
 

when i drive the car and the boost gets to 0.5 bar or just over it goes lame, i mean it still boosts a bit more but doesnt pull very hard, sounds like the ignition is retarding. when at stand still it idles slight irratic, between 800-1100, ive changed the maf, map and boost solenoid but no difference, i have also just replaced a coil, any suggestion to what might be causing this?? my97 wrx ra

have you uprated the DV

nope, havent touched it, all was fine til the coil went and i lost boost and went in limp home mode to subaru, come back on all 4 cylinders and then this problem

can anyone help PLEASE!

Has the ecu been reset

apparently it was cleared, so presume it to have been

It sounds like ti has gone into a "safe mode" where it detects a problem and it tries to stop the engine taking damage,

try reseting it yourself or do a diagnostic check on it

could the maf sensor of put in that mode then when i changed it? would i have to so called reset it even if i change that or will it automatically do it
??

sounds like youre playing the same game as me atm (MY95 WRX with scoobyecu)

replaced the MAF and the O2 so far and its still not happy

on replacing the MAF the CEL came on with and O2 error (typical)
replaced the O2, reset ECU everything was good and about 30 minutes

then back to square one
had a 60k service(inc plugs) and new coil packs not so long ago

ive had the diagnostics plugged in and it says everything is ok, do an ecu reset and it comes back to life for about 10-30 minutes

next on shopping list is a knocklink and a new boost solenoid.

think i mite have a spare boost solenoid in the shed :)

Before id go spending loads of money you guys id check for air leaks as there is alot of pipes that can be disturbed or disconected without even knowing you touched them, the other thing you can do is buy a can of leak detecting spray, it tells you how 2 use it on the tin

Martin

checked all pipes and they look fine turned the dump valve pointing back towards the air filter as subaru put it facing the intercoolor is this right?

new map, maf and boost solenoid still the same, any suggestions?? starting to rack my brains

leak detecting spray ???
sounds interesting, do halfords sell it?

xiw2155> have you had yours on the diagnosis computer? Where do you live? Is your spare solenoid anygood?

nr st. helens.

yeah i presume its good i swapped it for a new one and made no difference so it wasnt that, that was faulty.

let me find it first

some people keep telling me its in "limp home" mode

but others say not as the revs will happily go up and up beyond the 4k limit in Limp Home mode. but resetting the ecu does clear the problem temporarily.

unless there are varying stages of LHM, wher it cuts the boost but not the revs?

mine revs fine, its just not boosting past 0.5bar boost and if it does then it like drives as if firing on 3?? any suggestions

This is a long shot, but underneath the intercooler there is a small earth wire 10mm nut holding it on, if its loose slightly it causes the fault it seems your having! just check it &let me know what happens. (youll have to remove the intercooler to get to it

Martin

will check that wen i get in tonight.

if, failing that any other suggestions, could it be the wastegate actuator??

No not realy!
your actuator works off pressure not vac. so it is shut on idle so when acc. your boost solernoid pushes the waistgate open if that was faulty it would cause it to overboost!

EXACT problem on mine too.

I have it passing 0.5bar then smacking into the overboost mode. Painful.

BUT got check engine light and havent checked fault code yet.

Also faulty lambda and possibly a coilpack?

checked the earthwire no difference, handy info tho. is overboosting dangerous???

and i dont get any lights on at all, defo not in limp home mode, doing my t$ts in now as i aint a clue. still fairly new to it and exploring, any other things i should check???

well its been running strange today, sometimes 16psi (scoobyecu) sometimes 8psi.

got some new Bosch coilpacks (the ones imported from Australia)
replaced the the MAF andO2 last week.

gonna spend this weekend
-looking for leaking pipes and checking earths
-refit original dump valve and airbox
-fit new coil packs

im doing the same with the coil packs although mine will be just stock parts :(

let me know how you get on matey!

doing me head in now and ive run out of ideas??

anyone??

same here
 

I have exactly the same problem, sometimes 11.5psi then when i really need the boost it sits at 6psi. I've changed maf, manifold pressure sensor, dump valve and got replaced Boost Solenoid but still can't find problem. I'm thinking about buying a brand new boost solenoid but they want £170. if you find the problem pleaseeeeeeee let me know.

will do. my local scooby garage arent that helpful either, they dont know what it is so i guess i will have to find it myself, but its a bummer when you pull out and think sh*t wen over taking or out of a junction plus when some lil arsehole in a kitted up shi77er races you at lights and you get 0.5bar boost then farts like an ole grinner.

Im begining to think that its a fuel pump fault, a mate of mine is lending me his pump as he as an uprated one on his car but i wont get it till next sun. then i can let you know what that does, all the people at the subaru garages that we all seem to have spoke to dont know, but it seems to me as it must be quite common as where all having the same fault

I've got a similar problem on my ScoobyECUd '95 wagon - a couple of times a week my car will only push 0.5 bar instead of 1.1 bar.... Have cleaned the boost solenoid a few times but so far no luck. Rather than buy a new one at nearly £200 several people have recommended using a Dawes boost controller for under £50... Haven't got there yet since this problem is only mildly annoying currently. Knocklink is happy as a clam when running .5 bar boost so motor doesn't seem stressed by this so neither am I! :D

i have been sugested the same thing re:dawes device

BUT

isnt it safer to fix the problem rather than hide it?

I dont want to put in a dawes device only and risk the ecu not being able to go into LHmode when theres a real problem

Mark

Just spoke to another subaru dealers today they say (which i have read on here) its "sounds like a overfilled oil problem", but mines around 1/2 to 3 1/4 full the told me to drain out some more just below half, so i'll gie that a go!

Martin

BTTT