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Discussion Starter · #1 ·
The quick sum up is this: When tuned I have a "stutter". When not tuned the car runs like butter. RICA is looking at my downloads now but with the below info I'm wondering if anyone can point me in the right direction. (I do not think its the tune itself but the increased boost levels, so I doubt RICA can help with a remap)<p>Anyway, I finally installed a boost gauge and can now tell what the heck is going on, heres my findings: <br>When tuned I peak around 22psi and at peak boost is when this stutter happens. As it hits 22 it seems like it wants to go MUCH higher, but then I hear a "noise" and the boost flattens out while creating this stutter/hard felt loss of accel. This "noise" has a bit of a squeak to it, very mechanical, I am thinking its the wastegate flying open in a millisecond? In conjunction with the noise is the stutter in acceleration. <p>It sometimes spikes a good deal higher than 22 too (I think I saw 28 once <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/eek.gif" BORDER="0"> ) It stays smooth when it goes over 22psi though, until the "noise".<p>Any theories? Is this noise the wastegate?<p>**I'm wondering if the previous owner had a downpipe installed without an exhaust, causing these spikes on a stage 1 tune. How can I check this easily, any tell tale signs its stock or not???
 

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Re: Boost / Stutter thing, revisited (imageomega)

Have you tried dialing back your "waste gate tweak"?
 

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Discussion Starter · #3 ·
Re: Boost / Stutter thing, revisited (Oceans60R)

This problem was present long before I did anything to the wastegate. As I understand it this tweak only affects base PSI, and has NO bearing on peak PSI.<p>I had kind of ruled that out. Again, without the tune the car runs like butter.<p><br>Should also add: I've switched between the HDTCV and OEM, disconnected battery and grounded out, back and forth twice now. The HDTCV is much smoother all around and makes the stutter at peak kind of a "oomph oomph". The OEM TCV gives a "oomph oomph oomph oomph".... (aren't I so articulate and awesome with description?)<BR><BR>
<i>Modified by imageomega at 8:31 AM 7-14-2009</i>
 

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Re: Boost / Stutter thing, revisited (imageomega)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>imageomega</b> »</i></TD></TR><TR><TD CLASS="quote">This problem was present long before I did anything to the wastegate. As I understand it this tweak only affects base PSI, and has NO bearing on peak PSI.<p></i></TD></TR></TABLE><br>Having any changes above the base (stock is 7.5psi IIRC) waste gate setting can affect drivabilty and will be exacerbated by modified boost levels. <p>Its easy enough to dial back and would at least rule this out w/o guessing that the modification isn't having a negative affect. <IMG NAME="icon" SRC="http://********************/smile/emthup.gif" BORDER="0"> <BR><BR>
<i>Modified by Oceans60R at 6:47 AM 7-14-2009</i>
 

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Re: Boost / Stutter thing, revisited (imageomega)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>imageomega</b> »</i></TD></TR><TR><TD CLASS="quote">Should also add: I've switched between the HDTCV and OEM, disconnected battery and grounded out, back and forth twice now. The HDTCV is much smoother all around and makes the stutter at peak kind of a "oomph oomph". The OEM TCV gives a "oomph oomph oomph oomph".... (aren't I so articulate and awesome with description?)</TD></TR></TABLE><p>Did you give the car time to learn? ~50+ miles of driving, and ramping up from driving miss Daisy to Mario Andretti? Or did you just swap the TCV and stomped on the throttle?<p><br>Have you tried to go to a dealer to have your DTCs read?
 

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This may sound too obvious but what are the health of your spark plugs? Maybe when you hit peak boost on your tune it's blowing the spark out, creating the misfire you describe.<p>That would explain why without the tune loaded the car runs fine.<p>Surely worth a look.
 

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Discussion Starter · #7 ·
1) I will try dialing back the WG just for S&G's- but this problem was present before I touched the WG.<p>2) Yes, I let the TCVs learn. Not quite 50+ miles, but 20-30 with multiple engine cycles. Both TCV's exhibit this as soon as I hit peak boost with the tune, regardless if I stomp on it after 1 mile or 30 (which is the longest I was able to go without a push). Both TCV's are fine, after 1 mile or 30, when running stock software.<p>3) Haven't gone to the dealer with THIS problem but I have had my codes read recently for an FPS (replaced, fixed other issues but not this)<p>4) My spark plugs have been checked within 5k and were replaced about 10k ago. I thought this too but after a complete removal/reinstall, they all look good and gapped right.
 

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Re: (imageomega)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>imageomega</b> »</i></TD></TR><TR><TD CLASS="quote">3) Haven't gone to the dealer with THIS problem but I have had my codes read recently for an FPS (replaced, fixed other issues but not this)</TD></TR></TABLE><p>Give it a shot. Put everything back the way it was, get it to stutter over a day or two, then go to the dealer and check for DTCs <IMG NAME="icon" SRC="http://********************/smile/emthup.gif" BORDER="0"> <p>When you did the plugs, did you have a chance to check the coils?<p>Most likely unrelated, but probably a good idea to clean out your MAF too.<p>The HD TCV fittings are larger than the OEM unit. They can loosen up the hoses. Make sure the clamps are nice and tight.
 

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Discussion Starter · #9 ·
Re: (S60R1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>S60R1</b> »</i></TD></TR><TR><TD CLASS="quote"><br>Give it a shot. Put everything back the way it was, get it to stutter over a day or two, then go to the dealer and check for DTCs <IMG NAME="icon" SRC="http://********************/smile/emthup.gif" BORDER="0"> <br><b>cant hurt, except the wallet</b><p>When you did the plugs, did you have a chance to check the coils?<br><b>had a "cyl 1 misfire" code because of the FPS. Checked/changed everything multiple times before realizing it was the FPS. This was 5k ago, I had this issue then but had not traced it to boost peaking. The FPS fixed those codes and other behaviors, but not this stumble.</b><p>Most likely unrelated, but probably a good idea to clean out your MAF too.<br><b>havent done this, and I should</b><p>The HD TCV fittings are larger than the OEM unit. They can loosen up the hoses. Make sure the clamps are nice and tight.<br><b>I noticed this as well. I've got real deal flat head tightening clamps, both sides of each hose, with silicone tubing (except the "red" tube...gotta get under there at my buddies shop and haven't had a chance yet).<br></TD></TR></TABLE>
 
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