Sputter at high boost

[gti_kev]

It's definietly my REVO stage 2 tune. I'm over boosting which causes it cut fuel.
Revo tune requests levels very close to 180 bar which is what causes it to cut fuel. don't get why revo gets so close to the cut off.

Hey guys,
seems to me like a boost leak somewhere but my boost gauge is reading right, Its at 21inhg, peaking at 24ish, and holding around 18psi. BUT, last night i felt it bog out once on third gear right when it hit peak. I thought it was weird so i downshifted back into third and went WOT again, but everything was normal.
Now, this morning i tried passing a semi in third gear, same thing, it bogged/sputtered out, went normal, then bogged/sputtered again. So i thought to myself, fuck, maybe i gotta pull over cause its happening again. So as i was pulling over, i tried it to see if it'll happen again, and nope 3rd gear pulled through smoothly.
Kind of seems like fuel cut, like when trying to brake boost too much, and it just cuts fuel. Its exactly that feeling.

I doubt its the coil packs since I'm not getting a CEL, i know what the feeling is when its misfiring. I have new coils and R8 CP's.

I'll lift it up tonight and check my IC hoses, TBH, and TOP. I popped the hood and got under the car a bit but everything seemed good. Of course can be different under boost with pressure.

What do you guys think? anything else i should look for?
I'll find some VAg-com but in the mean while, ill appriciate the feedback.
Got track this weekend so i gotta get this fixed. I'd hate to waste a track day.

 

[Injen1us]

I had this on occasion when running the wrong gapped spark plug with my tune. Small bog, sputter at WOT 4-6k revs. Wasnt valve float cause a colder plug and tighter gap fixed it.

 

[toxicfusion]

I would check your plugs depending on how many miles you have on them.
Also, where was the last place you filled up at?

I've noticed with this car an drunning 93 oct on my Uni Stage 2... different quality fuels makes huge difference

Shell & Mobil gas = WIN. car feels strong and healthy every pull and gear. Other gas, I can feel the car being down on power and it cries.

 

[gti_kev]

I had this on occasion when running the wrong gapped spark plug with my tune. Small bog, sputter at WOT 4-6k revs. Wasnt valve float cause a colder plug and tighter gap fixed it.

Maybe, I'll check my plugs then. I have about 3-4k on them.
I'm running the NGK BKR7EIX that are gapped at 0.032.

I would check your plugs depending on how many miles you have on them.
Also, where was the last place you filled up at?

I've noticed with this car an drunning 93 oct on my Uni Stage 2... different quality fuels makes huge difference

Shell & Mobil gas = WIN. car feels strong and healthy every pull and gear. Other gas, I can feel the car being down on power and it cries.

I've always filled up with Chevron, never had issues.
Although I did fill up at a new spot I've never fill up at. Doubt that can be it, though. :iono:

 

[gti_kev]

Seems like it is a fuel issue. Anyone have any fuel issues? like injector wise??
Can it a tune issue?

 

[Mensurpj1]

does your boost guage flutter when it bogs? could be the wastegate

 

[gti_kev]

does your boost guage flutter when it bogs? could be the wastegate

nope. Everything on my boost gauge is reading fine. Looks normal is it has before. Its only happening on a specific RPM/speed and not a constant thing. It'll do surge, then try again, and it'll pull through smoothly.

 

[gti_kev]

So i talked to my tuner, said they have found other mk6's with this issue and it might be the fuel rail sensor. I'll log the car tonight though, hopefully.

 

[gti_kev]

So I brought it into the dealership and they're saying it's my fuel pump. I Need an upgraded one since its maxing boost at 32psi??? that's why it's falling on its face on 3rd gear at boost peak.
aren't our fuel systems good up too about 400hp??

 

[syonxwf]

So I brought it into the dealership and they're saying it's my fuel pump. I Need an upgraded one since its maxing boost at 32psi??? that's why it's falling on its face on 3rd gear at boost peak.
aren't our fuel systems good up too about 400hp??

Do you mean 23psi? Even 23 is a little higher than normal from what I'm seeing out of Revo (Spikes generally at around 21, maybe 22), but there's no way you're boosting at 32psi.

But aside from that, sounds to me like they're trying to get out of paying for a faulty part. I don't know much about them, so I don't know which would be failing; are they saying the HPFP or the LPFP?

 

[gti_kev]

Do you mean 23psi? Even 23 is a little higher than normal from what I'm seeing out of Revo (Spikes generally at around 21, maybe 22), but there's no way you're boosting at 32psi.

But aside from that, sounds to me like they're trying to get out of paying for a faulty part. I don't know much about them, so I don't know which would be failing; are they saying the HPFP or the LPFP?

Yeah that's the correct reading after they take out everything else. 21 max boosting but it's Fuel Rail/System Pressure is too High, HPFP.
Saying I have to upgrade to fuel pump in order to feed the correct amount.
I doubt that's the problem. I need to look at my hoses and possibly even my intake and maf sensor. I talked to Revo and said it can't be fuel pump, it's not the software, has to be a hardware problem. Once they're done with my water pump and valve cover leak, I'll check everything else again.

 

[Calkulin]

Fuel pump issues(high or low) will usually give a CEL for low fuel rail pressure(P0087), so if you're not getting that, then I don't think it's a fuel pump issue. If you can log, log the specified and actual fuel pressures and see if you have dips to eliminate the fuel pumps

 

[rpc07]

Yeah that's the correct reading after they take out everything else. 21 max boosting but it's Fuel Rail/System Pressure is too High, HPFP.
Saying I have to upgrade to fuel pump in order to feed the correct amount.
I doubt that's the problem. I need to look at my hoses and possibly even my intake and maf sensor. I talked to Revo and said it can't be fuel pump, it's not the software, has to be a hardware problem. Once they're done with my water pump and valve cover leak, I'll check everything else again.

I'm getting the exact same issue since the weather has been colder, I wouldn't go changing parts out yet it might be a software issue. I've been battling this issue with revo for 9 months or so the problem comes and goes and always throws fuel rail pressure to high code. I'm about to switch to a different company for tuning.

 

[syonxwf]

Yeah that's the correct reading after they take out everything else. 21 max boosting but it's Fuel Rail/System Pressure is too High, HPFP.
Saying I have to upgrade to fuel pump in order to feed the correct amount.
I doubt that's the problem. I need to look at my hoses and possibly even my intake and maf sensor. I talked to Revo and said it can't be fuel pump, it's not the software, has to be a hardware problem. Once they're done with my water pump and valve cover leak, I'll check everything else again.

Ah ok. Yeah, pretty sure the HPFP hasn't needed to be replaced really by anyone due to tune, and iirc, very few people have had any issues with the HPFP at all in our car.

I'm hoping for your sake though that it is a hardware issue and not the tune (as was suggested by the guy above me). Only for the fact that if REVO is anything like APR, you'll have this issue for a while before they actually come around to fix it, IF they ever do...:lol:

At least if it's hardware you have the option to replace it and have it fixed, that's all I'm saying

 

[gti_kev]

Exactly, never got a CEL.
I'll have to find someone that can log it.

Anything else I should look for? I lifted it yesterday hoses were all in tact and seemed normal. I guess I'll just have to wait to log it. Wonder if stage 1 would do the same.