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Weird Boost Problem*NEW PROBLEM*

Old 05-27-2008, 04:55 AM
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Default Weird Boost Problem*NEW PROBLEM*

So today on my way to the movies, an S2000 wanted to run me. So we went from a stop. I babied first gear, hit second gear perfect, but still was feathering the gas (had a 1/2 car on the guy) then finally had enough traction to floor it. I floored it and started to pull then all of a sudden, my car just stops like if I let off the gas but my foot was still to the floor. After about 1 second my car picked up again like if nothing happened.

I am on my stock clutch still and i'm making 270 hp/tq. I don't drive hard at all, but im thinking maybe my clutch was slipping

My buddy with a GTI said that GTI's have this problem when they upgrade their chips. He said its called boost surging and they fix this problem by replacing their N75 Valve. Do we have a valve similar to this? Could this be my problem too?

Any help is welcomed

NEW PROBLEM

So I thought my troubles were behind me but I guess not.

My car runs fine until I hit boost, and once I hit boost i Get code p0102 (MAF circuit low input) and the Throttle no longer works. My scanguage is hooked up and the Throttle position sensor reads perfectly fine. With the CEL on, I will go WOT and the TPS % increases but my car doesn't go anywhere, not until I downshift then the car will sputter along. Once I clear the code the car runs perfect, that is until I go into boost then it happens all over again.

I had an appointment this moring with my tuner, but wasnt able to make it because my car was running like ____. I also hear a click everytime i push the throttle

My question is, is my problem my MAF? I dont think its my throttle position sensor, since we have electronic throttles so i assume that the MAF code will affect my Throttle response.

I already cleaned the MAF with cleaner and reset the battery and it still does the same stuff. I just dont feel like spending $150 on a new MAF and it do nothing for me

Anyone have any clue?
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Old 05-27-2008, 05:17 AM
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when you stopped was the engine revving or did it drop off also?
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Old 05-27-2008, 05:39 AM
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clutch slippage means that your rpms go up while your speed doesn't while in gear and the clutch is engaged. so if that happened, you would have bounced off the rev limitor. or maybe that is what happened, you bounced off the rev limitor.

but as for valve, what kind of valve is an n75? you have valves on your car, but what does that one regulate?
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Old 05-27-2008, 07:40 AM
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Originally Posted by draxcaliber
clutch slippage means that your rpms go up while your speed doesn't while in gear and the clutch is engaged. so if that happened, you would have bounced off the rev limitor. or maybe that is what happened, you bounced off the rev limitor.

but as for valve, what kind of valve is an n75? you have valves on your car, but what does that one regulate?
I know for sure I didn't bounce off the limiter, My RPM's dropped as if my foot was off the gas yet my foot was floored.

My buddy said that the N75 valve controls the wastegate, but the GTI's have internal wastegates so I believe that this wont apply to me.

Thanks for the help so far. If anyone else can figure out what went wrong I would love some help. I'm not so ____ed that it happen as much as I lost the race, I was pulling on that sucker too! lol
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Old 05-27-2008, 09:53 AM
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fuel cut? maybe you need to upgrade to bigger injectors? just a suggestion...thats what it sounds like
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Old 05-27-2008, 11:44 AM
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sounds like tuning problem, maybe something changed that needs to be worked on

did you see your afr's when that happened? go try to replicate and report back with AFR and all that jazz.

also, if you can't replicate it then you are probably fine. if you can THEN we might have a problem
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Old 05-27-2008, 01:35 PM
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i have a similiar problem.. i hit the gas and my AFR goes so high on the aem the it makes 3 dashes, and my boost spiked to 7 and all i hear is lots of backfire like pop pop pop but im not going anywhere..
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Old 05-27-2008, 01:38 PM
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Maybe it's a throttle signal issue.. like for whatever reason the computer saw your throttle as closed - then picked back up the signal and opened throttle again.
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Old 05-27-2008, 05:21 PM
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Originally Posted by athletefeet66
fuel cut? maybe you need to upgrade to bigger injectors? just a suggestion...thats what it sounds like
Im running 550's so I think im ok

Originally Posted by aen
sounds like tuning problem, maybe something changed that needs to be worked on

did you see your afr's when that happened? go try to replicate and report back with AFR and all that jazz.

also, if you can't replicate it then you are probably fine. if you can THEN we might have a problem
I just got retuned about 4 days ago, If i remember correctly my A/F was ---

Originally Posted by SoFloTC
i have a similiar problem.. i hit the gas and my AFR goes so high on the aem the it makes 3 dashes, and my boost spiked to 7 and all i hear is lots of backfire like pop pop pop but im not going anywhere..
Sounds similar to me, do you still have this problem? Did you find a solution?

Originally Posted by B_Real45
Maybe it's a throttle signal issue.. like for whatever reason the computer saw your throttle as closed - then picked back up the signal and opened throttle again.
I was reading up on that too. Some people were throwing code P2111 and having the same issues as me, but my car didn't throw a code

Thanks for everyones help, Ill try to launch from a stop again and report back
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Old 05-27-2008, 05:22 PM
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--- = really high AFR.

translates to boost leak

go check all plumbing
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Old 05-27-2008, 05:39 PM
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Originally Posted by aen
--- = really high AFR.

translates to boost leak

go check all plumbing
As far as All my Vac lines and intercooler piping right?
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Old 05-27-2008, 05:45 PM
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oo i must have a leak then

but then again its not happening all the time? it will happen and then ill turn it off and let it sit for like a couple hours go for a ride again and it might or might not happen
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Old 05-27-2008, 06:10 PM
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sometimes couplers have a chance to settle then kinda flap away as you drive...or, depending on how much pressure...that's whats required to break the seal that the couplers make

check all lines/ic piping
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Old 05-27-2008, 06:22 PM
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MVMyTc and SoFloTC - you guys also need to make sure to fix any exhaust leaks before turbo - this could cause high AFR and slow spool.
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Old 05-27-2008, 09:37 PM
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Def sounds like a boost leak to me!!
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Old 05-27-2008, 10:40 PM
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I re-did my entire Vac Line setup and double checked all my couplers. Everything seemed to be fine

I took it out for a run and did a pull from a stop and it ran perfect,

Maybe it was a one time fluke?
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Old 05-28-2008, 12:12 AM
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maybe because you checked it you pushed something in lol. sometimes small boost leak = big problem
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Old 05-28-2008, 12:55 AM
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^^agreed.
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Old 05-28-2008, 05:55 PM
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Keep checkin all the ic piping often for the next couple of weeks or even better yet to a boost leak test!!!!!
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Old 05-28-2008, 08:03 PM
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if not leaks then tuning issue then.. -- is too lean
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