Stuttering acceleration - APR Stage 1

[DudeLePowSki]

http://forums.vwvortex.com/showthrea...art-hesitation.

This was the one... mine only happens when it's cold though

Oh sorry. I thought you were referring to the sound thread in which everyone jumped all over the guy.

My stutter is much more subtle than that and seems to happen whenever I am coming through 4000rpm in higher gears at about 75%throttle. Whistle stutters and so does acceleration. I am actually at the shop right now. They are going to reflash me. I'll keep you posted.

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[specialkk43]

Speaking of warming up, has anyone noticed a beeping sound when you let the revs get too high while the car is warming up? Is this a warning signal?

The beeping sound might be as you approach rev limiter... I am pretty sure it's actually a warning that can be controlled either thru vagcom or the MFD.

How high are you getting them?

I remember that this is your first stick shift car, and so I'm just gonna say this b/c you might not know, but you should NEVER get high in revs until the car is warmed up to full temp. Drive like a grandma until you are warmed up....

[JosephHatfield]

Another problem with an APR tuned vehicle. I'm beginning to get the impression these tunes are really not a good idea if you want a reliable, well-functioning, vehicle.

[specialkk43]

Another problem with an APR tuned vehicle. I'm beginning to get the impression these tunes are really not a good idea if you want a reliable, well-functioning, vehicle.

I wouldn't necessarily jump to that conclusion. Although if it makes you nervous, don't do it. But I, as well as plenty others, have had APR tuned vehicles for tens of thousands of miles with zero issues....

There may be problems here and there, but there are also problems with stock vehicles here and there.

[DaLeadBull]

The beeping sound might be as you approach rev limiter... I am pretty sure it's actually a warning that can be controlled either thru vagcom or the MFD.

How high are you getting them?

I remember that this is your first stick shift car, and so I'm just gonna say this b/c you might not know, but you should NEVER get high in revs until the car is warmed up to full temp. Drive like a grandma until you are warmed up....

It shouldn't be the rev limiter, I don't get much higher than 3000-4000 rpm, sometimes I have no choice but to rev it a little high in 1st to about 3000-4000 rpm when taking a left hand turn unless I shift mid turn.

[usurpers26]

You are beginning to get that impression?? Most of your replies are always in "the sky is falling" vain...you are slowly approaching "GreyCar" (i think that was his name) status

Another problem with an APR tuned vehicle. I'm beginning to get the impression these tunes are really not a good idea if you want a reliable, well-functioning, vehicle.

[DudeLePowSki]

Update:

Okay, Just got back from the tuning shop. They checked for codes - none. They reflashed Stage 1 and took it for a test drive and confirmed what I feel...yay! I'm not crazy. Their diagnosis was possible problem with diverter valve. They are convinced that the APR flash is simply enhancing the symptom that would be there if still stock.

I can either get the tuning shop to check the DV and pay a bit of $ for labour and possible replacement

or

They said they'd reflash to stock and I could take it back to the dealer for a check up under warranty.

The problem for me is that the dealer never takes the time to actually listen and diagnose the problem. I fear leaving my car there for a full day only to have them say there's nothing wrong with it. WWVD?

[BigmountainVMD]

Yeah, just throw more money at the problem by adding mods that people on the internet are telling you to do. Don't diagnose the problem first and fix it correctly.

Weren't you talking about buying an aftermarket boost gauge/tap?

Another problem with an APR tuned vehicle. I'm beginning to get the impression these tunes are really not a good idea if you want a reliable, well-functioning, vehicle.

Actually its the opposite. The tune is merely exposing an issue that was already there, so when it is fixed, your car will be more reliable than before. Boo-ya.

[Rdurty2]

Weren't you talking about buying an aftermarket boost gauge/tap?

A boost gauge is a good instrument to have to use for diagnostics. If it's a DV issue if the OP had a boost gauge he would see that the psi is not holding the way it should be, or its fluctuating.

That is why ATL was probably recommending it.

[Lent53]

Which boost gauge do you guys recommend?

[Rdurty2]

Which boost gauge do you guys recommend?

Podi. Mine gets delivered today

I will be putting up a DIY and review hopefully sometime this weekend.

[BigmountainVMD]

Podi. Mine gets delivered today

I will be putting up a DIY and review hopefully sometime this weekend.

I was watching the thread on the blue needle matched ones as opposed to the current "blue light" gauges --> no luck it seems.

[KimKman]

Just did a stage 1 APR today V3.1. So far no stutter, no whistle. Very solid improvement over stock. Will be great for some time until I collect the parts needed for II+

[JosephHatfield]

Actually its the opposite. The tune is merely exposing an issue that was already there, so when it is fixed, your car will be more reliable than before. Boo-ya.

I guess that's a better way of looking at it...now we get to blame VW instead of APR.

Did I mention I suffer from OCD? I want my car to be PERFECT, damnit!

[Atl-Atl]

Update:

Okay, Just got back from the tuning shop. They checked for codes - none. They reflashed Stage 1 and took it for a test drive and confirmed what I feel...yay! I'm not crazy. Their diagnosis was possible problem with diverter valve. They are convinced that the APR flash is simply enhancing the symptom that would be there if still stock.

I can either get the tuning shop to check the DV and pay a bit of $ for labour and possible replacement

or

They said they'd reflash to stock and I could take it back to the dealer for a check up under warranty.

The problem for me is that the dealer never takes the time to actually listen and diagnose the problem. I fear leaving my car there for a full day only to have them say there's nothing wrong with it. WWVD?

Suuuprise suuuprise. Hopefully your shop did some decent diagnostic work. The stock DV on the R is very good compared to previous generation VW DVs but lately people have been posting boost numbers as high as 30psi with an APR tune. This is incredibly high and I am not surprised at all if a stock DV can't handle that pressure.

Replacing the failing stock DV with another stock DV may not fix the problem. This part wasn't designed to handle what the APR tune is throwing at it so the DV will most likely fail again. If your dealer is as troublesome as you claim you should find a new dealer, or try to make friends with an actual tech not just the deal with the service writer. Sometimes you can get much farther explaining your situation directly to the technician instead of playing telephone via the service writer.

If you trust the shop that did the APR tune, have them diagnose the situation. Hopefully they are accurate and honest. Unfortunately you have opened the modification can of worms. It can go well from here and be fixed cheaply and easily or it can go in the opposite direction.

[Atl-Atl]

Weren't you talking about buying an aftermarket boost gauge/tap?

Not necessarily, its possible to borrow a boost gauge and temporarily hook it up for diagnosis. This should be one of the first things the shop does for diagnosis anytime they are dealing with a situation where more than factory boost is called for(APR chip) and you are experiencing the symptoms OP is experiencing.

[BigmountainVMD]

Well it's good to know there is a simple test for that. Now if only it was as simple to check what's going on in these Rs with tranny/clutch issues...

[Rdurty2]

Well it's good to know there is a simple test for that. Now if only it was as simple to check what's going on in these Rs with tranny/clutch issues...

People don't know how to drive stick properly?

[terps85]

I flashed my car about 3 weeks ago, just today noticed this issue. Up until today it has been running great. In 6th gear cruising at 65-70 at about 2800 revs the turbo felt like it was dead and had very little boost and the car was not pulling nearly as hard as it should. I'm going to take it into the shop where i had it flashed (New German Performance), but worried this will be a recurring issue if it the diverter valve. Curious to hear how things go for you with this since it sounds like I am in the same boat.

Update:

Okay, Just got back from the tuning shop. They checked for codes - none. They reflashed Stage 1 and took it for a test drive and confirmed what I feel...yay! I'm not crazy. Their diagnosis was possible problem with diverter valve. They are convinced that the APR flash is simply enhancing the symptom that would be there if still stock.

I can either get the tuning shop to check the DV and pay a bit of $ for labour and possible replacement

or

They said they'd reflash to stock and I could take it back to the dealer for a check up under warranty.

The problem for me is that the dealer never takes the time to actually listen and diagnose the problem. I fear leaving my car there for a full day only to have them say there's nothing wrong with it. WWVD?

[BigmountainVMD]

So if you upgrade the diverter valve to something aftermarket that holds against the increased pressure... are you putting other intake/turbo components at risk?

[DudeLePowSki]

I flashed my car about 3 weeks ago, just today noticed this issue. Up until today it has been running great. In 6th gear cruising at 65-70 at about 2800 revs the turbo felt like it was dead and had very little boost and the car was not pulling nearly as hard as it should. I'm going to take it into the shop where i had it flashed (New German Performance), but worried this will be a recurring issue if it the diverter valve. Curious to hear how things go for you with this since it sounds like I am in the same boat.

The only thing the tuning shop thought was weird is that normally if the diverted malfunctions it throws a code and there were no errors codes found.

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[terps85]

Hmm that is wierd, so do they think it is something other than the diverter valve? Are you planning on having the shop flash your car back to stock config for taking it back to the dealer?

The only thing the tuning shop thought was weird is that normally if the diverted malfunctions it throws a code and there were no errors codes found.

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[DudeLePowSki]

Hmm that is wierd, so do they think it is something other than the diverter valve? Are you planning on having the shop flash your car back to stock config for taking it back to the dealer?

I haven't decided yet. I am probably going to drive it for another week or 2 just so that I can compile some instructions on how to accurately reproduce the problem. At that point I'll probably get it flashed back to stock and take it to the dealership IF the problem persists. If the problem goes away, I'll be in limbo.

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[terps85]

I hear ya. Well I'll let you know what I decide to do and how it goes...I'm going to take mine into the tune shop this week sometime

I haven't decided yet. I am probably going to drive it for another week or 2 just so that I can compile some instructions on how to accurately reproduce the problem. At that point I'll probably get it flashed back to stock and take it to the dealership IF the problem persists. If the problem goes away, I'll be in limbo.

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[Siliconrane]

Can you pull logs VIA VCDS?

(Yes - I got this from GOAPR)

1 001-1 Engine Speed
2 014-3 Misfire Sum
3 031-1 Lambda, Current Value
4 054-3 Accelerator Pedal Position
5 054-4 Throttle Plate Angle
6 101-3 Injection Timing (Median)
7* 103-1* Current Fuel Pressure*
8 114-4 N75 Duty Cycle
9 115-3 Boost Pressure (Specified)
10 115-4 Boost Pressure (Actual)
11 230-1 Rail Pressure - Specified
12 230-2 Rail Pressure - Actual

This will help us determine what is going on. It could be several factors.

I have heard a couple of people mention the Diverter valve. I have spoken to APR about the diverter valve and have asked them several times if an aftermarket valve is required. They told me that the OEM revision D valve that our car uses is more than adequate to hold their stage III kit which puts MUCH more stress on the car than our little K04 does.

I agree that there is still a possibility that you have a failing diverter valve, not arguing that. I would suggest that you run some logs and get some hard evidence before we come to any conclusions. There are other things in the system that could cause problems.

[terps85]

So would it be worth me asking NGP to pull these logs? Do these files get rewritten each time you shut off then turn on the car, or does it just keep logging data to the same file until it reaches some memory limit if any?

Can you pull logs VIA VCDS?

(Yes - I got this from GOAPR)

1 001-1 Engine Speed
2 014-3 Misfire Sum
3 031-1 Lambda, Current Value
4 054-3 Accelerator Pedal Position
5 054-4 Throttle Plate Angle
6 101-3 Injection Timing (Median)
7* 103-1* Current Fuel Pressure*
8 114-4 N75 Duty Cycle
9 115-3 Boost Pressure (Specified)
10 115-4 Boost Pressure (Actual)
11 230-1 Rail Pressure - Specified
12 230-2 Rail Pressure - Actual

This will help us determine what is going on. It could be several factors.

I have heard a couple of people mention the Diverter valve. I have spoken to APR about the diverter valve and have asked them several times if an aftermarket valve is required. They told me that the OEM revision D valve that our car uses is more than adequate to hold their stage III kit which puts MUCH more stress on the car than our little K04 does.

I agree that there is still a possibility that you have a failing diverter valve, not arguing that. I would suggest that you run some logs and get some hard evidence before we come to any conclusions. There are other things in the system that could cause problems.

[Siliconrane]

So would it be worth me asking NGP to pull these logs? Do these files get rewritten each time you shut off then turn on the car, or does it just keep logging data to the same file until it reaches some memory limit if any?

The car itself does not keep any of those values. You will need someone with a Ross-Tech Cable and a laptop to capture those values from the ECM while the car is operating. If you know anyone that has a Ross-Tech cable, they will be able to log those values. Follow the instructions on THIS website and post up the log (send it to APR as well as they will want to see this information to help diagnose). This is the primary way to diagnose boost / fueling problems.

[DudeLePowSki]

The car itself does not keep any of those values. You will need someone with a Ross-Tech Cable and a laptop to capture those values from the ECM while the car is operating. If you know anyone that has a Ross-Tech cable, they will be able to log those values. Follow the instructions on THIS website and post up the log (send it to APR as well as they will want to see this information to help diagnose). This is the primary way to diagnose boost / fueling problems.

Would this be something an APR dealer would know? My car was already in the shop and if it wasn't for you I'd have no idea what to ask for. They scanned for error codes but they definitely didn't do any scan logs like those instructions ask for.

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[Siliconrane]

They should know how to do this. If not - find another apr dealer and report them to corporate.

Would this be something an APR dealer would know? My car was already in the shop and if it wasn't for you I'd have no idea what to ask for. They scanned for error codes but they definitely didn't do any scan logs like those instructions ask for.

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[DudeLePowSki]

Suuuprise suuuprise. Hopefully your shop did some decent diagnostic work. The stock DV on the R is very good compared to previous generation VW DVs but lately people have been posting boost numbers as high as 30psi with an APR tune. This is incredibly high and I am not surprised at all if a stock DV can't handle that pressure.

Replacing the failing stock DV with another stock DV may not fix the problem. This part wasn't designed to handle what the APR tune is throwing at it so the DV will most likely fail again. If your dealer is as troublesome as you claim you should find a new dealer, or try to make friends with an actual tech not just the deal with the service writer. Sometimes you can get much farther explaining your situation directly to the technician instead of playing telephone via the service writer.

If you trust the shop that did the APR tune, have them diagnose the situation. Hopefully they are accurate and honest. Unfortunately you have opened the modification can of worms. It can go well from here and be fixed cheaply and easily or it can go in the opposite direction.

Sorry Atl-Atl, I missed this post somehow. Thanks for the insights.

After doing some reading about people with new GTI's experiencing the exact same thing as me, I am now back to thinking it's wastegate as mentioned by tonymy01 earlier. I am also thinking that maybe his experience with having the ECU learn when and when not to dump boost might apply. Since I just got reflashed, I am going to drive it for a couple weeks and see how it goes.

[terps85]

Got ya, thanks for the heads up on that. NGP should have these but we shall see. Strangely enough the car felt normal driving it today, i.e very responsive at 2600+ RPM and similar to how it drove when i first flashed it. I'm not sure what to think now, we'll see how it drives tomorrow.

The car itself does not keep any of those values. You will need someone with a Ross-Tech Cable and a laptop to capture those values from the ECM while the car is operating. If you know anyone that has a Ross-Tech cable, they will be able to log those values. Follow the instructions on THIS website and post up the log (send it to APR as well as they will want to see this information to help diagnose). This is the primary way to diagnose boost / fueling problems.

[speeedfrk]

Got ya, thanks for the heads up on that. NGP should have these but we shall see. Strangely enough the car felt normal driving it today, i.e very responsive at 2600+ RPM and similar to how it drove when i first flashed it. I'm not sure what to think now, we'll see how it drives tomorrow.

that just makes me wonder if there are some adaptive values that will change with your driving habits. im definitely no software engineer so dont take anything i say with any worth. just wondering really.

[terps85]

Yeah I don't know how to explain it either, I guess its a possibility. All I know is that something weird was def going on.

that just makes me wonder if there are some adaptive values that will change with your driving habits. im definitely no software engineer so dont take anything i say with any worth. just wondering really.

[DudeLePowSki]

Okay so this is a very logical explanation of the wastegate to backup tonymy01:

This is just for information purposes because I keep reading threads on here that are about the pronounced whistle after a tune. This is an oversimplification of what's going on.

There are many different turbo noises but I think the one everyone is talking about at 4500 RPM is wastegate flutter. It's normal. The wastegate is a essentially a valve that covers a bypass route for exhaust (think blow-off but for exhaust), the valve is actuated when boost pressure has reached a set limit. This keeps the boost level from climbing higher than a desired amount. A boost controller is what is used to change the wastegate's setting. When it opens it will "flutter" because if you keep the wastegate fully open you will drop boost almost completely, so it opens and closes rapidly in order to maintain boost pressure as the desired amount or the wastegate is only partially open (ever crack the window open when you're on the highway? It's a whistle noise because there's a small opening for which gas can pass through).

This makes sense and it explains exactly what I 'feel'. So after the Stage 1 tune, boost is going higher and reached at a faster rate so my wastegate is blowing it off at a more 'notcieable' level. My question now is,

1) Is the wastegate blowoff significant enough that a driver could actually feel it?

2) If it is possible to FEEL wastegate flutter, is there something in the ECU or the APR tune that can or needs to be adjusted in order to minimize it or is it simply 'the way it is'.

If that's just normal than I am cool with it. If not, I'd kinda like to get to the bottom of it.

[koma]

Well if a tune was calling the wastegate too aggressively you could lose boost pressure rapidly. I'm not a tuner but I'd assume you could actuate the wastegate when you wanted via ECU. Say the the tune called the wastegate aggressively at around that RPM, which would quickly dump exhaust through the wastegate and stop the turbo from spinning (imagine having a wheel attached to something spinning at great speed and you suddenly pulled the driving mechanism off, the wheel loses speed quickly).

Reading your thread it's not a diverter valve problem period. A diverter valve is on the intake side, it prevents already pressurized air (air that has been compressed in the compressor and has already made it passed the compressor on it's way to being consumed) from entering the engine. The situation when a diverter valve (or blow offs) is called is when you have built up boost pressure and you can't consume the already pressurized air, this is when you abruptly let off the throttle (shifting does this too). The diverter valve, diverts already pressurized air back into the intake (http://www.extremevdub.com/articles/...i/default.aspx) before the compressor to be reused. So unless you're letting off throttle your diverter valve has nothing to do with your particular issue.

I would take it to another shop that has a boost gauge they can temporarily install (or even use VAGCOM to monitor pressure) and run through some logs of 4 gear pulls from 2500 to just before redline. This will show you how much variation there is in boost pressure. Different tunes will do different things here but what you want to look out for are large spikes/drops in pressure (in your case probably drops) across your rev range. You'll have a large rise when boost builds (I think our cars are roughly 2800-3200) until it "peaks" and it should either level out (stay steady) or decrease steadily. It shouldn't have a rapid up and down in boost level.

Good luck and let us know!

Reposting here.