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Discussion Starter · #1 ·
My friend just got a 02 wrx with a 2.5l sti short block. He has a probably with the car not boosting. You can hear the turbo spool but it feels like its not getting any boost. What are somethings that could cause that.
 

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i had a problem with no boosting and im pretty sure my prob was having a cold air intake and i put the stock air ram back on so i think it was feeding air into the filter on an angle and screwing up the maf sensor, so maybe check with the intake system just a suggestion
 

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Have you hooked a gauge up to see if there is any boost? There could be a leak somewhere between the turbo and the throttle body (y-pipe,intercooler, and all couplings in between). Also, the wastegate may be stuck open or malfunctioning. The MAF really shouldn't effect boost levels too much, as the wastegate is dependent on boost levels to operate. However, if the MAF were improperly located or contaminated it would effect engine timing which could make it feel like you don't have any boost.
 

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Discussion Starter · #5 ·
It still has the stock air box. We checked all the piping from the turbo to the throttle body. Nothing was loose. Check engine light is on. Sometimes it has spells were it idles rough. The clutch is slipping but that should not be the problem. How could you test a air bypass valve (blow off valve).
 

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the problem is your ecu has cut all boost parameters because it is experiencing excessive knock. This is called running on mechanical boost. Your stock ECU will do this to prevent you from blowing up your motor. there is no boost hit at all, but the turbo still spools? its spooling solely off of exhaust gas pressure with no electronic parameters. I am having the exact same problem with my cobb stage II wrx right now and I can't figure out how the hell to fix it! Its either a stuck open/poorly adjusted wastegate or leaky BOV or something else. I wish I could get my car running right too!
 

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It still has the stock air box. We checked all the piping from the turbo to the throttle body. Nothing was loose. Check engine light is on. Sometimes it has spells were it idles rough. The clutch is slipping but that should not be the problem. How could you test a air bypass valve (blow off valve).
Find out what the code is first.If the cruise control light is flashing as well then thats bad.I suggest buying a tactrix cable and downloading Enginuity to log with.Seriously,it's 10X faster to diagnose stuff if you can datalog the car.Even if you don't know what your looking at,other people do.You can just post the log.When you test for boost leaks you need access to an air compressor.This is how you test for boost leaks.


http://forums.nasioc.com/forums/showthread.php?t=1085758&highlight=leak+testing
 

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Hi everyone.
Was there a solution found to this issue? Having the same exact perform with my current build 02 2.5 swap. Have did 2 smoke tests 1 from the intake side and another from the bov. Had only a couple of minor leaks that I fixed. Next steps, planning on removing the tmic to check everything closer, check turbo, upgrading my downpipe, replacing the down stream 02 (already replaced upstream during build), check wastegate. Considering compression test and leak test... The engine has less than 50 miles on it iag stage 2 tuff and bring tuned by Eric at torqued performance.

Any thing else I'm missing I should check?

Signed.. Need my daily drive back in my bugeye
 
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