n339jmb

as title, my wrx has started overboosting to 1.37bar..... has had new maf fitted couple of days ago as had this problem last week... when car hits 4k in 3rd, boost hits 1.37 bar and then hit feul cut (standard ecu)

car was running fine for couple of days after fitting new maf but now it has started all over again...

standard recirc, decat exhaust, k&n cone filter......

any ideas or suggestions??

markb_s1

wastegate actuator?

greenfumb

restrictor pill

n339jmb

have checked pill, has a 0.8mm welding tip in the pipe....

as for actuator, have adjusted the arm to make it longer so the boost doesnt come on as quick... now hits peak boost at 5k.....

am running straight from turbo to actuator and am still hitting 1.3 bar of boost, when it should be 0.5.... really doing my nut in....

tjmatt

iTrader: (1)

Well it can only be that either the wastegate is jammed shut, or the actuator is broken, or it has been adjusted so much so that the wastegate can never open.

Try a car/bicycle tyre pump (not high pressure) on the actuator with it removed to see if the arm moves.

n339jmb

will give that a try.. will lengthening or shortening the arm help??? have made it longer but all that does is prolong the boost peak to 5k... also have a 0.8mm restrictor pill in bottom pipe of solenoid, is that the right size?? read somewhere that it should be 2mm

joz8968

iTrader: (13)

Could be a split vac pipe, giving the overboost situation too. Check all vac pipes that go to/from the BCS...

dbay

iTrader: (21)

it should be 2mm pill for an early classic/3 port setup. does sound like gate or actuator issue as said. maybe worth cleaning the boost cellunoid to see if that makes a difference

Turbotits

iTrader: (2)

De-cat + cold weather and no mention of mapping would be my thoughts

joz8968

iTrader: (13)

Well spotted - could well be........

53

iTrader: (41)

+1

Put the airbox back on aswell, poor car will be lean as **** at 1.37bar.

n339jmb

have cleaned boost solenoid, replaced all hoses.. no leaks... seems the pill is wrong size, but i was of the understanding that a smaller pill meant less boost??

no cel or error codes.... as said, am running straight from actuator to turbo and is still hitting fuel cut.. boost gauge shows 20psi ;-(

n339jmb

quick update.. fitted new actuator, overboost problem solved... but... now its only boosting to 10psi....lmao..

never easy with a scooby is it,,,, couls this be down to the 0.8mm pill instead of 2mm?? but i was of the understanding that a smaller pill meant more boost...

joz8968

iTrader: (13)

OEM boost target for your car is 0.79bar or c.11.6psi.

But how accurate is your boost gauge though? Does it have a low res. scale and/or a fat needle, etc.? This could easily account for the 'robbed' 1.6psi...........?!

n339jmb

did think about that.. to be honest i am happy with it.... cheap *** gauge that was already fitted when i got it.... car shifts,doesnt cut fuel so i am a happy chappy... can actually enjoy driving it now ;-)

thanks for all the advice guys... mucho appreciated

joz8968

iTrader: (13)

Yeah, if it 'feels' right and hauls sweetly right through the rev range, in all gears, then it most probably IS alright.

n339jmb

bloody hope so... what about the restrictor pill... its got a 0.8mm welding tip in it... shouldnt it be 2mm?? does the smaller pill increase or decrease boost?

joz8968

iTrader: (13)

On a 3-port, I thought the smaller the hole, the less boost too(?)

The reason being that a large hole allows for more air to bled away from the w/g, hence it staying shut for longer, hence boost build-up... Or that's what I always thought.

n339jmb

Is confusing me lol.. If standard is 2mm then what is my 0.8mm pill doing in regards to boost pressure??