Surging/hesitation/pulsing under hard acceleration

Mods: APR stage 2 tune, Carbonio stage 1 intake, GHL catted DP, Magnaflow CB, BFI stage 1 torque mount insert

This issue happens seemingly randomly, and lasts for maybe a week or so and then goes away for awhile. When I go WOT (or hard acceleration) in 3rd gear or higher (I don't really go WOT in 1st or 2nd for obvious reasons) there is some weird surging feeling and you can hear it. It's almost as if I was slightly letting off the gas and then getting back on. It is not a rhythmic surging (it is irregular in beat). It kind of reminds me of when you watch a video of a car going around the Nurburgring, and then under WOT the exhaust note/RPMs kind of fluctuate when going over the undulations on the track.

I know that my clutch is slipping. In 4th and up it will slip at low/moderate RPMs and WOT. But this feels different because when the clutch slips the RPMs will rise steadily for a little, then hold constant until the rest of the transmissision speed catches up.

I've heard that it could be a fuel filter issue? What do you think? I'd prefer to not spend the time/money on a new fuel filter if it's something else

VAGCOM It.....it could be WG Duty Cycle or slipping clutch. I think its the latter.

Have you tried data logging your incident?

Edit: Grambles in first lol

You mean do a log session? What should I look for in the data? If you're just talking about codes, there are none

Regarding logging: does it matter if it's a 3rd gear pull instead of 4th?

Yes, a log session. I would log the following

Fuel Pressure Specified
Fuel Pressure Actual
Boost Specified
Boost Actual
N75 Duty Cycle
MAF
RPM
Lambda

That should get you started. 3rd or 4th doesnt matter as long as you dont break traction during the run and you use it consistently.

Thanks, I'll post the log here when I do it

Check this:

http://www.goapr.com/support/datalogging.php

As a tip for future logging sessions, you can save each logging configuration so that you don't have to check the boxes every time. Taken from: Ross-Tech: VCDS Tour: Advanced Measuring Values

VCDS lets you save a list of Advanced Measuring Values, to be easily accessed later on. For instance, if you often log Vehicle Speed, Engine Speed, Intake Air Mass, and Ignition timing, then you can create a file to quickly load those selections again. To save a set of items, click on the VCDS logo found on the top left corner of the item selection window, and then select "Save selection to file":

Click to expand...

I have the APR round 1-5 selections saved, as well as a few others I like. It may not help you this time, but it's a big time saver the next time you are going to do logging.

veedoubleme said:

As a tip for future logging sessions, you can save each logging configuration so that you don't have to check the boxes every time. Taken from: Ross-Tech: VCDS Tour: Advanced Measuring Values



I have the APR round 1-5 selections saved, as well as a few others I like. It may not help you this time, but it's a big time saver the next time you are going to do logging.

Click to expand...

Good idea, thanks for the tip! :thumbsup:

if that's a slipping clutch then that gives you more reason to make that group buy happen haha!

intoflatlines said:

Good idea, thanks for the tip! :thumbsup:

Click to expand...

Try out the attached set of files. They are my saved measuring block sets for APR's 5 round logging. All you should have to do is load one up for each round and you won't have to tick all the boxes. This should save you a lot of messing around between each round.

Let me know if they work for you since I've never tried to transfer from one VCDS user to another. It should work though — they are just text files with a .a01 file extension. If they work I'm going to post them in my VAG-COM thread.

Seems worth a try. :iono:

yes log 3-4 WOT runs on the same stretch of road one after another, Traction control off, windows up.

Then send to Grambles. he will decipher as he knows his shite.

Other logging block options as per APR:

ROUND 1 LOGGING:
Use for Boost and Fueling
Diagnosis Item # Vag-Com
Block # Description
*Not Applicable to EA888 TSI/TFSI Engines.
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

ROUND 2 LOGGING:
Use for Boost and Timing
Diagnosis Item # Vag-Com
Block # Description
1 001-1 Engine Speed
2 003-4 ignition Timing
3 020-1 Cylinder Ignition Angle Delay (cyl 1)
4 020-2 Cylinder Ignition Angle Delay (cyl 2)
5 020-3 Cylinder Ignition Angle Delay (cyl 3)
6 020-4 Cylinder Ignition Angle Delay (cyl 4)
7 031-1 Lambda, Current Value
8 054-3 Accelerator Pedal Position
9 101-3 Injection Timing (Median)
10 114-3 Engine Load (actual)
11 115-4 Boost Pressure (Actual)
12 230-2 Rail Pressure - Actual

ROUND 3 LOGGING:
MAF/Load-Specific Diagnosis Item # Vag-Com
Block # Description
*Not Applicable to EA888 TSI/TFSI Engines.
1 001-1 Engine Speed
2 003-2 Intake Air Mass
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*
8 114-1 Engine Load (specified)
9 114-3 Engine Load (actual)
10 115-3 Boost Pressure (Specified)
11 115-4 Boost Pressure (Actual)
12 230-2 Rail Pressure - Actual

ROUND 4 LOGGING:
Misfire-Specific Diagnosis Item # Vag-Com
Block # Description
1 001-1 Engine Speed
2 003-2 Intake Air Mass
3 015-1 Misfire Cyl 1
4 015-2 Misfire Cyl 2
5 015-3 Misfire Cyl 3
6 016-1 Misfire Cyl 4
7 054-3 Accelerator Pedal Position
8 054-4 Throttle Plate Angle
9 101-3 Injection Timing (Median)
10 115-3 Boost Pressure (Specified)
11 115-4 Boost Pressure (Actual)
12 230-2 Rail Pressure - Actual


ROUND 5 LOGGING:
Use for Boost and Timing Item # Vag-Com
Block # Description
1 001-1 Engine Speed
2 003-2 Intake Air Mass
3 003-4 ignition Timing
4 020-1 Cylinder Ignition Angle Delay (cyl 1)
5 020-2 Cylinder Ignition Angle Delay (cyl 2)
6 020-3 Cylinder Ignition Angle Delay (cyl 3)
7 020-4 Cylinder Ignition Angle Delay (cyl 4)
8 031-1 Lambda, Current Value
9 054-4 Throttle Plate Angle
10 114-4 N75 Duty Cycle
11 115-3 Boost Pressure (Specified)
12 115-4 Boost Pressure (Actual)

BTW- be sure to post what u find.

Sub'd

Thanks guys. I'll try to load the files onto my computer later tonight.

Quick question (too lazy to search/do research): what do 3rd and 4th gears top out at in MPH? I need to find a good stretch of road for this that would hopefully not result in me getting ticketed/arrested.