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Discussion Starter #1
I was driving around today with no problems at all for about 20 minutes, full boost runs and everything. Then I went to nail it in 1st, and at about 4500-5000 rpms the car violently shuddered, like all boost and power was suddenly cut. I was able to rev to redline fine without any boost, and if I didn't go completely WOT. I searched and found some previous people who had problems related to a leak in an aftermarket BOV, but mine's stock. Any ideas? This really sucks cause I'm planning on driving it cross country in a week:eek3:

btw: I have a gutted uppipe, bosal DP and catback and am running a Cobb stage 2 reflash.

thanks
 

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It sounds like you hit the fuel cut due to over boosting. The only thing that makes me doubt this is the fact that you were running in 1st (where it is hard to get high boost) and you are using a Cobb reflash for boost control. The Cobb should not be letting you boost high enough to hit the cut.

Do you have a MBC or EBC? If so, what level of boost are you running?

Do you have a boost gauge? If so, did you see what your boost hit when the problem occurred?

Can you get on boost again or is the car keeping you from boosting now?
 

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Discussion Starter #3
First off, great avtar.

I don't have any EBC or MBC, the only control of boost comes from the Cobb reflash. I do have a boost gauge and I didn't notice the psi when it happened.

Strange thing is, I just went out again and it seemed fine (but I didn't do any 1st gear pulls). I floored it in 2nd and 3rd from about 3k to 6500 with no problem. The boost gauge was reading normally. Hopefully it'll just work itself out but it felt horrible, I wonder how bad it is for the car. Is there any explanation for why this would happen more often in 1st than any other gear?
 

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Discussion Starter #4
I've noticed that this stutter really only happens in 1st or 2nd gear, when I really hit it. It also seems to happen more coming out of corners, or when the car is generally unsettled. I'm hoping there's some kind of physical fuel delivery problem. Also, I"VE GOTTEN NO CELs. So it shouldn't be running very lean or be a cylinder misfire. Anybody who has any idea PLEASE help, I'm plannign on a 7000 mile trip in a few days!! Thanks
 

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sounds to me that it is maby your clutch.. how many miles are on your car? most people feel thier clutch shudder down in the lower gears because that has the most stress on the tranny.. 1st gear and 2nd gear soo if you have alot of miles on your car or go to the track alot that might be your problem.. i cant see the problem being anything with your engine because if that was the case a check engine light would come on.. when you drive your car normal does it still shudder in 1st and 2nd gear?
 

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blackboost said:
I've noticed that this stutter really only happens in 1st or 2nd gear, when I really hit it. It also seems to happen more coming out of corners, or when the car is generally unsettled. I'm hoping there's some kind of physical fuel delivery problem. Also, I"VE GOTTEN NO CELs. So it shouldn't be running very lean or be a cylinder misfire. Anybody who has any idea PLEASE help, I'm plannign on a 7000 mile trip in a few days!! Thanks
Sounds like fuel starvation. Does it happen more when you don't have a lot of gas in your tank?
 

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Discussion Starter #7
how many miles are on your car?

I have 27k on the car, never taken it to a track

when you drive your car normal does it still shudder in 1st and 2nd gear?

Nope, it only stutters under high boost in 1st and 2nd gear. I can go to redline fin if I'm gentle on the gas, even if I'm pushing about 8psi. I really dont think it has anything to do with the clutch.

Does it happen more when you don't have a lot of gas in your tank?

No. I havent noticed any difference. I agree with you though hippy, it feels like a fuel problem. It's just odd that previous posts about this problem usually indicate a problem with a BOV leak. I just really hope the dealership can find a leak/ fuel problem before the trip. Maybe the fuel filter is the problem (hopefully)?

ps. I can drive the car fine, especially on the highway, it's only a problem if I really get on it in 1at and 2nd. Do you think I'm doing damage to the car running it with this occasional problem?

I really appreciate the feedback guys
 

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Is your car an o4? The o4 ecu has been known to cause that type of problem in certain situations(from what I hear).

peace
 

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blackboost said:
Then I went to nail it in 1st, and at about 4500-5000 rpms the car violently shuddered, like all boost and power was suddenly cut. I was able to rev to redline fine without any boost, and if I didn't go completely WOT.
It sounds like fuelcut, but I never experienced it in the first gear before. !
 

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Discussion Starter #11
My car is an 02.

Anyway, I just dropped it off at the dealership and their wrx expert drove it. When it happened in 1st gear he said, wow this is f***ed up! He said there's a cylinder misfire, but he can't understand why I haven't thrown a CEL. I told him I have a CObb reflash and now he thinks that some parameters may be off. Very frustrating, they're working on it right now, the last thing I want to hear is that I need a new ECU for 500 bucks. :(
 

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Did this happen when you would go to switch gears or did it happen during acceleration??

A couple times when I really had my foot down I would go for a gear change & it would completly cut out. It might of been my driving.
 

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Discussion Starter #13
Turns out I had a bad wire in the brown harness directly behind the battery. Apparently, under heavy acceleration, like in 1st gear, the car moved in a way that a connection between a wire and the harness severed, causing a misfire in one of the cylinders. Well, thank god it's fixed now, I'm leaving for a cross-country trip in a few hours! So if anyone has a similar problem make sure you check out this harness for bad connections.

ps. The dealership fixed it under warranty, and they found something I would have never seen. Happy customer
 

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Damn, thats a weird issue. I'll be sure to check my wiring the next time I'm under the hood.
 

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Turns out I had a bad wire in the brown harness directly behind the battery. Apparently, under heavy acceleration, like in 1st gear, the car moved in a way that a connection between a wire and the harness severed, causing a misfire in one of the cylinders. Well, thank god it's fixed now, I'm leaving for a cross-country trip in a few hours! So if anyone has a similar problem make sure you check out this harness for bad connections.

ps. The dealership fixed it under warranty, and they found something I would have never seen. Happy customer
What wire was bad? I think I’m experiencing same problem !
 
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