I have a 2002 STI and I don't know what the issue with is with it. It drives absolutely perfect and idles good and builds boost perfect but once it hits 1.3 bar its like a sudden loss in power and changes sound like brrrrrr. It tries to rev on but it feels hard. It usually goes to 1.5 bar, it revs perfect when sitting but just not under higher boost when it gets around 1.3. No engine lights or anything I checked the pipes with smoke machine I don't seem to find any leaks but it was not under huge pressure when doing this. There's a bov fitted the past 12/13 years, there was a small leak in the blocked off recirculation hose I fixed this but it didn't change anything. MAF sensor was cleaned it was dirty but still the same. I'm also after putting a new boost solenoid, fuel filter and pfr7b spark plugs and still nothing. Coil packs were changed last year. There's a wallbro 255 pump put in few years ago. Any help would be appreciated thanks
Boosting/ignition issue
- Thread starter Dylan_C123
- Start date
I have a 2002 STI and I don't know what the issue with is with it. It drives absolutely perfect and idles good and builds boost perfect but once it hits 1.3 bar its like a sudden loss in power and changes sound like brrrrrr. It tries to rev on but it feels hard. It usually goes to 1.5 bar, it revs perfect when sitting but just not under higher boost when it gets around 1.3. No engine lights or anything I checked the pipes with smoke machine I don't seem to find any leaks but it was not under huge pressure when doing this. There's a bov fitted the past 12/13 years, there was a small leak in the blocked off recirculation hose I fixed this but it didn't change anything. MAF sensor was cleaned it was dirty but still the same. I'm also after putting a new boost solenoid, fuel filter and pfr7b spark plugs and still nothing. Coil packs were changed last year. There's a wallbro 255 pump put in few years ago. Any help would be appreciated thanks
Yes the pill is there and all, I made the mistake of switching it to wrong side few days ago and couldn't get any more than 0.5 bar. Put it back to correct side and it's back to this issue now. Also yes mapped at this no controller
Full transparency, I'm no guru, but have a check at the waste gate actuator.
Check if rusty, or if closing fully and opening fully. Should be able to move it by hand, does take a bit of force.
Someone will be on with a more knowledgeable solution for you but least you've those bits checked anyway.
When she loses power, does it drop back to 0.6 bar until you start it again or does it still hit 1.3?
Check if rusty, or if closing fully and opening fully. Should be able to move it by hand, does take a bit of force.
Someone will be on with a more knowledgeable solution for you but least you've those bits checked anyway.
When she loses power, does it drop back to 0.6 bar until you start it again or does it still hit 1.3?
Actuator seems fine it opens with bit of force, I put new coil packs in it last year only 3k on them at the minute and haven't changed the MAF yet only cleaned it. Was dirty enough when I did it
Ideally you’d have to have Subaru monitor or laptop on it to see your voltages when the fault is happening
I'll take it out one of the days tomorrow and check the voltage I have an obd cable that shows live data on the phone. Thanks
is it mapped? any mods done to it?
Just boost set to 1.5 bar 325hp. Original prodrive cat in it and tomei catback. Bov as well and wallbro 255 pump everything else is stock
yeah it has, been mapped that way since bob rawle done it in 2008
if youre getting knock then it might reduce the IAM (ignition advance multiplier) which usually pulls timing and reduces boost.
You can see it with a proper scan tool, SSM on a laptop or BTSSM which works with a phone.
it should be 16 if all going well, the closer it gets to 0 the worse its knocking and everything reduces.
On a standard map if it gets to 6 then it pulls timing and will reduce boost to gate pressure.
Does it run fine if you start and stop the car again? (sometimes they will run okay with a low IAM until another knock event happens)
You can see it with a proper scan tool, SSM on a laptop or BTSSM which works with a phone.
it should be 16 if all going well, the closer it gets to 0 the worse its knocking and everything reduces.
On a standard map if it gets to 6 then it pulls timing and will reduce boost to gate pressure.
Does it run fine if you start and stop the car again? (sometimes they will run okay with a low IAM until another knock event happens)
sometimes i find after starting it from cold the 1st pull under boost i do it can get near the 1.5 and then big loss in power and back to same issue.
maybe this is knock occuring and timing does be pulled then? any ideas what could cause this?
maybe this is knock occuring and timing does be pulled then? any ideas what could cause this?
sounds like it could be that, but it's hard to tell without checking the data really.
Could be a number of things, fuel has gotten worse since 2008 which would cause it.
Could be running lean under boost which would cause it too.
it's all guessing really unless numbers are checked.
Has it only started happening recently out of nowhere or been there awhile?
Could be a number of things, fuel has gotten worse since 2008 which would cause it.
Could be running lean under boost which would cause it too.
it's all guessing really unless numbers are checked.
Has it only started happening recently out of nowhere or been there awhile?
out of nowhere really, last saturday took it out was fine then sunday it started happening
definitely do not go into heavy boost until it's diagnosed, if you're boosting on a lean condition it will cause damage.
MAFs also fail the wrong direction as in when they start to fail they will start to run lean, and they are slow to throw a code if they do at all for them
MAFs also fail the wrong direction as in when they start to fail they will start to run lean, and they are slow to throw a code if they do at all for them