No Boost on 02 wrx

Tonight right after I left work my car quit boosting. It was fine for about the first mile then heard strange whoosh type sound followed by no boost:ugh: The car seems to run fine otherwise. havn't had a chance to look at it realgood yet. Any guesses on what the hell the cold did to my car? It's got an invidia up/catless tbe with a stage 2ish tune (14psi) if that makes any difference...

 

Do you hear a big air sucking sound and/or car bogs down when you should be hitting boost? If so, check those IC hoses and clamps before anything else. sounds like something came loose

 

Hey nice guess! I just came in from the very unheated garage and the ic pipe right off of the turbo came off... that and the waste gate arm disconnected. Strange. Is it supposed to be held on with a cotter pin, or does it just snap on? I just put it on. Hands were too cold to muck with the ic pipe, gonna try it later.

 

Dang I was about to guess that too :LOL: The wastegat eis held on by a little "c" clip, IIRC

 

I'm just glad it's something easy. Can any harm come from this little mishap?

 

:rockwoot:glad it was easy....common problem

the c clip IS a bit strange though

 

So I'm still fairly new to this turbo thing, can the waste gate being disconected for a short time do anything harmful? If my thinking is correct the waste gate spring will just keep it closed without the arm attached, correct?

 

That's the same thing that happened to me, i have boost then no boost after that. i checked the hoses to the turbo and found that my turbo inlet hose was loose. fixed it and no problems now.

 

maybe your stock BCS took a crap, sounds like you are running only w/g pressure

 

That's wastegate boost pressure.

Did you log IAM? If that drops low enough (due to excessive knock), the car will go into "limp mode" and disable boost control.

If it's not the ecu cutting boost control, the next thing to check would be for something mechanical -- ie, bcs lines & uppipe or tmic hose leaks. It's also possible that your bcs may be shot.

 

The IAM was good at 16 all the time. No negative KC or feedback KC at all. I thought that it could be the solenoid. Josh has an interesting set up, he has a replacement prodrive ecu. If i remember correct the boost came late in rpm range.

 

Well then it sounds like it's a mechanical issue.

 

is there a way to test bcs? Josh check and see if your waste gate arm is even connected to the solenoid. And I would recomend you taking that bov off untill you figure out the boost problem. You are running such low boost that the spring in it coils be too tight and that could be harmfull.

 

I've had the WG arm pop off of the door flapper thingy on the turbo before. The car gets really loud (sounds like a tractor, lol) and won't even make positive boost. It's probably not that.

 

yeah, true. Could it be just loose than?

 

I highly doubt it. It's probably either an exhaust/boost leak (both are pretty noisy), or something is wrong with the BCS system (cracked vacuum lines or broken BCS). My guess is going to be BCS related due to the boost levels that were logged.

 

its this thing if i am not mistaken

 

that is an apexi, doesnt look anything like the stock unit.

 

yes you nitt

 

Unsure as to exactly where the BCS is located on the bugeye, but it's got a couple vaccum hoses going to/from the turbo, WG, and post MAF.

Shibbs' BCS install tutorial should at least give you an idea of were to look.

 

yup, should at least be on that side and look generally the same...

 

the myth is becoming less and less, its ultra sad.

 

I think it looks kind like the stock one.

 

lookign for exhaust leak inspect the 02 sensor in up-pipe make sure its not loose...


we can take a look over it saturday too if you ahvent figured it out by then

 

You don't have a boost gauge?

I went through quite a mess like this troubleshooting boost issues - I woulda never known I even had issues if I didn't have the boost gauge.

BCS is basically the little dark blue plastic cylinder thingy bolted to a metal bracket on the passenger side front strut tower, with 2 vac lines coming out of it, one jutting out the bottom, and one out the side. It'll have a "Denso JAPAN" sticker on it.

It's a very functionally simple device and it'll make audible clicking noises if it's working. To test this, you can do it the hard way like I did, which is to rig up a connector and physically wire it straight to the battery to see if it clicks, or you can do it the easier way that I found out a bit later

Under your driver's side dash should be 2 green connectors that should normally NOT be connected. They are the test connectors. Plug them into eachother, and turn the ignition to the "ON" position and you should get a bunch of activity in the engine bay. The radiator fans will cycle on and off, and solenoids and relays and stuff will click on and off to test functionality. This is where you run to the BCS and put your ear close to it to hear if it's clicking or not. Should be a very fast rapid-fire clicking.

Don't forget to unplug the green connectors when you're done.

 

would he have cels if there was a problem with bcs?

 

If you start up the car with the BCS disconnected, yes, it will throw a cel, so if there really was a problem electrically with the BCS, the ECU will flag it. But if the BCS was just gummed up or stuck or dirty, it probably won't throw a cel.

I opened up the thing before - it's a really simple device. It's basically just a little rubber valve inside there with an electrical magnet attached to it. When it gets a current to turn on, the magnet activates and lifts the rubber valve open. If it's gummed up or sticky, the magnet will still activate but it won't be strong enough to break the stickiness, so the valve stays shut or doesn't open all the way. This is what causes annoying boost issues.

 

I happen to have a stock one from my 07 in my trunk if you want it. haha

 

Josh, have you ever mucked with your vac hoses around your turbo?

You didn't reverse the restrictor pill, did you?

 

if you have never noticed it before, and this is the boost you have been running this whole time.....your probably missing the restrictor pill.

 

your car seemed to be driving very well on the fun run.

As mentioned...if you're running wastegate only I'd check the restrictor pill and bcs and the vac hoses connecting to the bcs.

fyi- If needed I have a stock bcs laying around that you can have.

good luck bro

 

Get your self a boost gauge that reads in psi. IMO, its easier to read and is more accurate.

 

Yeah, no question, a GMBCS requires a tune.