Boost Delay? Need help troubleshooting.

[iiCaptain]

I swapped tunes on my accessport to a 93 octane stage 2 tune I had used before, and afterwards noticed an issue with acceleration. Anytime I step on the throttle, it builds a little boost, hesitates, and then builds the rest. It doesn't affect normal driveability, just any time I get on it. It's most annoying on shifts, as after I let out the clutch and get on the gas it hesitates and then the torque "punches" I guess is a good way to put it. I took a datalog to make sure I wasn't imagining things, and I found a ~400 ms pause as the boost builds. From no throttle to full throttle the boost pauses halfway at 6-8 psi for about 400ms before it continues and builds full boost at a normal rate. I've swapped tunes and the issue still follows, and I've stayed on the same tune now for a full tank of gas to try and let the tune adapt to see if it was that, didn't fix it. Out of curiosity I tried NLS (I normally don't use it) and it's still there.

Now I'm 99% sure this popped up when I switched tunes, but I'm not sure. I don't normally row gears and usually roll into the throttle which makes it a lot less noticeable. Still there, but harder to notice.

There's no codes or faults or anything, so I'm not sure where to start.

Here's some info on the car and thing's that might've changed.
-Attached O2 spacer to middle O2 sensor (cbfa). Don't think it is this due to me driving for about a week on this before this issue popped up. The reason I swapped tunes was to test the spacers.
-Haven't tackled carbon buildup yet (74k miles). No other symptoms of carbon buildup yet.
-Have CAI, any chance the filter didn't do enough filtering and messed up the MAF?
-When I searched this I just saw a bunch about the throttle adaption. Tried it and it did nothing to fix this issue.

That's all I got, appreciate any help. I searched for a while and didn't find much of anything online so not sure what to do.

 

[GolNat]

when were the plugs and coil packs changed? What gap are you running on the plugs?

 

[iiCaptain]

when were the plugs and coil packs changed? What gap are you running on the plugs?

Coils replaced about 15k miles ago and plugs 10k miles ago. Oem R8 coils and whatever the plugs are that stratified recommends. Gapped within .024" to .028" which they also recommend.

 

[GolNat]

15k miles is a lot for a set of coils and 10k on plugs is also. I’d replace those.

 

[iiCaptain]

15k miles is a lot for a set of coils and 10k on plugs is also. I’d replace those.

I'm hesitant to replace coils due to cost and I expected more life out of them. Plugs might make sense but again I expected some more life out of them, at least with what I've seen on here for change intervals when tuned. I don't mean to sound cheap. I'll try replacing the plugs but while they are ordered any other possible sources I could check? I have tons of time this week but next week I have none so I'm trying to get to the bottom of this quickly.

 

[This is Ryans face]

15k miles is a lot for a set of coils and 10k on plugs is also. I’d replace those.

"a lot" is a bit of a stretch here. I don't think you should have to swap either out unless you're running copper plugs or performance style parts for bigger builds that take more of a beating. If OP has the R8 coil packs, he should be fine.

 

[GolNat]

I know it’s not many miles as other cars get 100k out of coils and plugs. Search the forum.

it’s common for these cars when tuned to go through coil packs and plugs every 10-15k miles. I had to replace my R8 coils after around 10k miles.

Buy from FCPeuro so you can swap them and only pay for shipping.

 

[JOHNDERS2586]

I wonder if it could be clutch slip? Especially when you punch it, vs rolling on.. I know that when I switched to a KO4 setup (from stage 1) with a custom tune, under normal driving up to about 8 psi is common an doesn't really tend to want to push past that point, unless I'm pushing the throttle down more aggressively, then it builds full boost. So I noticed that slight delay there , I'm assuming maybe because the wastegate is set to crack at around 8 PSI, perhaps there is some delay in the transition of all the moving parts and computer readings, to building up the full boost pressure. but that's purely speculation..

 

[Thumper]

I know it’s not many miles as other cars get 100k out of coils and plugs. Search the forum.

it’s common for these cars when tuned to go through coil packs and plugs every 10-15k miles. I had to replace my R8 coils after around 10k miles.

Buy from FCPeuro so you can swap them and only pay for shipping.

Yeah, can't recall every seeing anything recommending 10k for coils, plugs most definitely. On my Stg3 when I was driving it more often I did 12k on the plugs and they weren't done for but certainly close. Now it gets more track than street driving and I just change them every year (thanks FCP!).

The plugs take a beating with the extra pressures and heat but the coils just take electricity and juice it up to spark, other than the tendency to come loose from the engine vibration they are not directly affected by higher tunes.

Plus, if a coil was bad it would cause a misfire which then would possibly cause a boost issue. If there is no timing pull and no misfire I don't see where the relation to the boost delay is.

To me it almost sounds like a gremlin in the DV maybe. The odd thing is it's exactly 400ms every time? If it was a weird delay each time then might be thinking something odd allowing boost leak and then sealing but at an exact 400ms each time, sounds more like something actuating to release and hold boost at that level and then changing it's mind.

Have you tried going back to the factory map? Just to see if the same issue is there?

EDIT: Went back and reviewed your log. You are logging a LOT of things at once, that cuts down on detail as it can only sample so many items at once, too many points and it could be a long time before it samples again. The timing change right at the boost building is odd but the knock count is 0. Although it could miss a knock with the gap in sampling, still would expect a code if it was bad.

I would run a log with just the timing and knock, boost and RPM for a good baseline then switch to the factory map and do the same.

 

[iiCaptain]

I appreciate all of the knowledge you guys are sharing. I'll go back and run some logs tonight with less variables. I mainly just used the preset it already has on there, as I don't know what to log and what not to. I'm enjoying learning more about this stuff though as I research, hopefully it will be useful some day lol.

I've tried other stage 2 maps but not the factory map. Will try that as well. I've only done a couple logs so far, but the issue feels very consistent (happens every single time with the same delay, duration, etc.) but I don't have enough data to prove it yet.

One thing I did notice from the datalog is that the AFR at WOT is slightly outside the range of what stratified says it should be within. Stratified says it should be between 11.6 and 12.2 but about each point logged at full boost is slightly richer (11.3-11.5 and 11.2 at redline). Not sure what to make of that or even if it's normal, but I figure can't hurt to point out.

Will update soon with more datalogs, and hopefully get plugs installed tonight or tomorrow whenever I get them. Looking back at the ones I bought last year they might've been fake ngk plugs on amazon which would make sense now.

 

[iiCaptain]

Changed spark plugs and that didn't work but I realize I made a mistake. I thought I was on the low torque tune which peaks at around 17 psi but I was on the high torque tune which peaks around 21 psi. Out of all the runs I only peak at 19 psi. I ruled out boost leak early because of this, but if a boost leak can cause this, I probably have one and just wasted $50. At least I have new plugs for summer.

Also the plugs look fine and if they are fake I genuinely cannot tell. Didn't save the old package. Which was the easiest tell.

I updated the spreadsheet with a bunch of runs now, I think I'm going to chase after a boost leak next, unless there's something in the logs that says otherwise.

 

[Alpinee30]

All of my coil pack issues have always thrown faults mk5 or mk6 .

OP Are you tuned by stratified? Use their log table and post the full log please. Stratifieds pre set table logs N75 duty

 

[iiCaptain]

All of my coil pack issues have always thrown faults mk5 or mk6 .

OP Are you tuned by stratified? Use their log table and post the full log please. Stratifieds pre set table logs N75 duty

I am but not sure what you mean by log table. I have a link in the first post to the datalogs?

 

[Alpinee30]

I am but not sure what you mean by log table. I have a link in the first post to the datalogs?

They have a preset log table available install it to your Accesport. Without all the extra stuff you're logging that's useless, I'd like to see certain things. Are you WOT and gear all that. Could be a boost leek your car is down about 13psi at 3120 rpm compared to some of my old logs with the same stratified setup but its assumption because a how your logging.

 

[iiCaptain]

They have a preset log table available install it to your Accesport. Without all the extra stuff you're logging that's useless, I'd like to see certain things. Are you WOT and gear all that. Could be a boost leek your car is down about 13psi at 3120 rpm compared to some of my old logs with the same stratified setup but its assumption because a how your logging.

I've looked up and down their website and they mention it on the how to datalog blog post, but never actually link to the table or anything. The only thing I can find is what they make you log when doing a MAF calibration:

MK6 GTI Datalogging Parameters

AFR

APP

Ambient Air Temp.

Boost Press.

Cam Angle Actual

Coolant Temp.

EGT Manifold

ETC Angle (Actual)

Exh. Mass Before Turbo

Final Timing

IAT

Injection Time

Knock Ret. Cyl. 1

Knock Ret. Cyl. 2

Knock Ret. Cyl. 3

Knock Ret. Cyl. 4

LPFP Duty

LTFT

Load Actual

Load Req. Max

MAF

Man. Abs. Press.

RPM

Rail Press. Com.

Rail Press. Actual

Rail Pressure Target

Requested Load

STFT

Trgt. Boost Press.

Trq. Actual

Trq. Modeled

Tumble Flap Position

Turbine Press. Flow Ratio

Vehicle Speed

WG Can Trgt. PR

WG Ex. Mass Flow

WG I Factor

WG P Factor

WG PID Result

WGDC

Hopefully this is what you're referring to. If so I'll get some more logs by tomorrow.

Almost all of the logs start in second, and keep going through third, sometimes fourth. There was one I think that started in third but that was it.