darryl

hi guys,
need your help with this problem I just incurred. My car suddenly sounded louder (cooler to me) then I noticed that it's not making any boost. Well it made 1lb of boost when I hard-accelerated in 3rd gear. Otherwise it's just a fun-sounding car now with no boosted power.
It is a 2002 WRX, modified back in 02 to the APS/Cobb Club Spec, then I reflashed the ecu a while back, two years ago in May. It's run fine all this time. I'm sure this lack of boost is related to the car having become louder. I just don't know where to start to trouble-shoot it.
thanks for any help,
darryl

mmboost

iTrader: (2)

Can you get high RPMs? Does the car feel like its not making boost? How are you reading boost?

If the two things are related, it might be an exhaust leak before or at the turbo, a baaad one. what is modified because engine management? Turbos also muffle exhaust noise, if your turbo has gone south...

jason

darryl

The car will run near to the redline, and it makes about 1 pound of boost in 3rd gear. I hope it's an exhaust leak, but I fear the turbo hasa gone south on me. The exhaust noise is louder but not loud enought o make me think I have an exhaust leak. The car idles fine, there are no ce lights. My boost gage is an Autometer vac/boost, and the vacuum at idle reads about 19 inches (normal). So I guess I need a new turbo?

mmboost

iTrader: (2)

You missed one question, does the car feel like its making boost?

I can't really say what's wrong with your car. You'er not really giving good indications. How do you know its not "loud enough"? What does that mean? Have you heard exhaust leaks on a boxter engine before? You've said nothing about your setup other than the EM changes.

Who knows, you might have just popped a vacuum/boost hose somewhere. Have you looked around at all?

jason

darryl

Sorry for the lack of info,
My car is a 02 WRX sedan. It has the APS/Club Spec kit: tbe, intake, bov, intercooloer hose. The Unichip was rem oved, and the ecu reflashed to Cobb's stg2/93 octane for the Club_Spec.
The car does not feel as if it's making boost. I do not hear the familliar turbo whine; I don't hear it spooling whereas I could before. Granted, I cannot tell if it's loud enough based on what an exhaust leak sounds like on a boxer engine. So, OK, it might be an exhaust leak. The car is louder so it might be anything. That's why I'm asking. One thing I did was tighten the wastegate actuator, but that was several months ago. I do not run the car hard, except for a rare burst here and there. The car has a boost gage which reads 19 inches at idle. I checked hoses and can't find anything apparently wrong. I will try to get under the car today.
Does the ej20 have a history of warped exhaust manifolds? I'll do a search for that.
Darryl

mmboost

iTrader: (2)

Warped exhaust manifolds? You mean at the flange where it meets the exhaust ports? If you've never unbolted your exhaust manifold I doubt you have a leak there. It would be quite loud.

Did you check the air flow to and from the turbo and intercooler? Its really hard to remotely diagnose this stuff with so little info about what's going on. Sorry, man.

jason

mmboost

iTrader: (2)

Oh btw what did you do to your wastgate again? Did you add length or subtract length? What were you trying to accomplish?

jsaon

darryl

problem solved. I was under the car and found no leaks. Took the heat shield off to check the turbo and saw the actuator arm was off the wastegate! The horseshoe retainer was missing. So most of the exhaust gas was bypassing my turbo. Hard to imagine the wastegate port flowing enough exhaust to limit the turbo to only 1-2 lbs of boost, but it does. Impressive.
So I wound up getting spare retainers from Autozone (29cents ea). I put one on, and was istantly back in business.
As for adjusting the arm length, I shortened (subtracted) length. I wanted to put a bit more
tension on the wastegate. The ecu learns it soon enough. I was trying to improve the car's off-the-line drivability. Not jackrabbit starts, but to just eliminate the bogging. I've noticed an improvement insofar as closed loop partial throttle boost. There's suppose to be some of that anyway, IIRC. Anyway, I ran out of adjustment, but the car still does not spike, nor does it go beyond 16psi, which is within the parameters of the Cobb stage2 reflash.
Like I said, I don't run the car hard anyway. But I do like drivable cars even if they are little four-bangers.
Moral of the story? Carry Spare retaining clips a 10mm wrench and small needle-snosed pliers. Just in case.

mmboost

iTrader: (2)

Ah, glad I revisted the wastegate idea, must jogged yer brain

The turbine wheel isn't much more than twice the width of the wastegate, so with an wide open wastegte cap you're losing perhaps 40% of your exhaust flow just by the size of the ports. Now, take into account that the exhaust going through the turbine has to get through all those fins while the exhaust going through the wastegate has no obstruction with a wide open cap. Makes a lot of sense to have an almost total loss of boost under your conditions.

Glad its fixed, congrats

jason

darryl

thanks for your support, Jason.
I was actually looking for leaks at the turbo when I saw the problem instantly upon removing the heatshield. Rather be lucky than good!
good forum.
Darryl