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Discussion Starter · #1 ·
ey everybody,

i was doing laps at brainerd the other day and when i was coming down the straight at about 5500rpm in 5th gear i hit what i think was fuel cut (car back fired and lost all power for a second) i thought i might have hit the rev limiter. But on the next lap at the same rpm (which i was now paying attention to) it happened again. I pulled off the track and popped the hood. There was a drop of oil just below the throttle body slightly towards the passenger side of the car. I thought it was leaking out of the intercooler so i removed the bov, but there was no oil. I then noticed a very small rubber hose had popped off the intake manifold. I put it back on and now it doesn't cut out in fifth anymore but at WOT (in all gears) there is a hissing sound coming from the engine possibly from the bov (sounds like it is coming from around there). Also at WOT my a/f's have gone from 10.9 to 11.3. Since my stage 2 i've never seen anything other than 10.9 at WOT. I've also noticed a ticking sound (may have been there before but i don;t remember it) it sounds almost like a fan ticking. The car is still boosting around 17.5 and doesn't feel like it has lost power, but something is definately not right. Can anybody help???
 

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Discussion Starter · #2 ·
I just did another quick wot run and a/f's hit 11.6......what could be causing this??
 

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Discussion Starter · #3 ·
i am going to check all vacuum lines once im off work....any other ideas?
 

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Discussion Starter · #4 ·
well i still have this problem, and now it is down on boost... makes 14.5 on stage 2 and doesn't hold it like it should stock, nevermind on stg 2 It used to make 17.5. I suuspected a vacuum/boost leak so after replacing my cai with the factory unit and checking intercooler connections as well as various other hoses and such i took it to the dealer. The dealer was of no help whatsoever, they did not find a vaccum leak and thats all they did. The mechanic who i was dealing is suppose to be their best (i sure hope not) and told me that the car is just regulatiung the boost (beacuse of weather changes) electronically via the bov and that the factory boost guage is not an accurate measure of boost. When i questioned why my a/f's changed they said that if in fact it did change that the ecu would know and throw a cel. Im don't know how they checked for a vacuum leak, but i suspect they may have just used a diagnostic tool. Im not sure if the mechanic actually doesn't know what he is talking about or if he is just trying to get rid of me. Anyways i'll be following up with the service manager tommorrow. So, back to the problem....assuming that the dealer actually tested for a vaccum leak and there isn't one, what else could be going on??? Any chance im leaking boost directly out of the turbo somewhere? I don't know what else to do, so any help would be lifesaving.
 

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Discussion Starter · #5 ·
i have now figured out (with some help from nasoc) that the hose that blew off the manifold was the fuel pressure regulator vacuum hose. I don't know how this can explain my loss of boost, it may just be a coincidence.
 

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Nelly said:
i have now figured out (with some help from nasoc) that the hose that blew off the manifold was the fuel pressure regulator vacuum hose. I don't know how this can explain my loss of boost, it may just be a coincidence.
I wish I would have seen this post earlier :( Yes, that is the FPR vacuum hose. The scary thing is that when people blow this hose off, they often loose the motor. Our Fuel Pressure Regulators are rising rate. Thus, when you are running 20psi the fuel pressure regulator is actually jacking up the fuel pressure by 20lbs such that you are running 63.5psi instead of 43.5psi. When you blow off this hose, the FPR no longer gets a boost reference. Thus, the car runs dangerously lean and the motor can have SERIOUS issues. Check all of your vacuum hoses to ensure things are AOK. Is the car running aok at part throttle? Any smoke out the tailpipe? What is your idle vacuum (on your boost gauge)?

t
 

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hmm, I guess I should check this holes on mine since I had that little overboost pop noise issue once.

But i am still making 18psi on my stage 2.

Anyone have a picture of the hose I should be looking for.
 

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Discussion Starter · #13 ·
wolfplayer: thanks for the help......my idle vacuum seems to be normal, the stock boost gauge reads about -.07 MpA . The car runs perfect at partial throttle, besides the loss of boost there are no other issues (that i can notice). At cold startup there is the usual puff of smoke, but thats it. Should i assume that i still have a vacuum leak even though the dealer said otherwise? Im unsure if they did a proper vacuum leak test, or just checked the computer. I'll check into that.
 

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Discussion Starter · #14 ·
I flashed my ecu back to stock and did a 5th gear`pull last night to watch a'f's and boost, i hit fuel cut and got a cel while only boosting 14psi no boost creep!.....before i ran into this losing boost problem i would get serious boost creep even in 4th gear, a/f's were 11.1 a touch leaner than pre-problem wot a/f of 10.9. I was gonna reflash stg 2 so i could read the cel code, but after i got gas today the cel went away.
 

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Discussion Starter · #15 ·
i have an appointment at the dealer on friday so hopefully they can get it figured out.
 

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Discussion Starter · #16 ·
i got another cel again. The cel code is P0244 turbo wastegate selenoid "A" range/performance. Anybody know wht this means?
 
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