Stumbling under high boost.

[Enzomnia]

So my car has a problem and I'm wondering if anybody here could give me an idea of what could be the cause.

It seems to be running perfectly fine at idle and when I drive normally/not gunning it, but as soon as I try to put the pedal to the floor, the car stumbles and won't go anywhere. I do have a JB4 installed and have the fuel gauge hijacked to show boost. It seems that anything under 10psi the car runs fine, but at around 12 psi, it stumbles, feels like misfiring, and eventually the CEL comes on. When I go back to cruising the CEL goes away and the car runs fine. Unfortunately I had the auto code clearing on so I didn't catch the code that set the CEL. I'll have to do it tomorrow after work.
I'm only running map 1 too.

Also, I did try running NOs octane booster about a week ago. I ran map 5 for autotune and it was running perfectly. It was reaching about 15 peak psi. I wonder if it has anything to do with what's happening now.

A little info on the car:
2011 N55 135i.
6spd

Mods:
CP-E chargepipe
Jb4
AFE intake
Downpipe

Any info on what is happening would be helpful! I was thinking maybe a crack resulting in a boost leak somewhere since it's only happening at high boost, but I don't really know much on FI cars.

Thanks!

[Fed P]

Getting the code will help a lot in going from speculation to an actual diagnosis. At higher boost the fueling system also has to work harder, so it's hard to say anything with any degree of certainty right now. Let us know =)

[mike@x-ph.com]

Post your code and a log.

[Enzomnia]

Originally Posted by Fed P

Getting the code will help a lot in going from speculation to an actual diagnosis. At higher boost the fueling system also has to work harder, so it's hard to say anything with any degree of certainty right now. Let us know =)

Originally Posted by mike@x-ph.com

Post your code and a log.

So after letting it sit overnight and removing and reinstalling the intake, chargepipe, and wiring the USB cable, I gave it a run.

It ran perfectly fine as far as I can tell and threw no codes.
Makes me paranoid that it'll come back. I guess I'll leave the auto code clear off for now in case it comes back.

I did do a log, although I'm not sure how to read it LOL.
The longest pull was in 3rd gear running map 1.
I still have the JB4 interface on if you want me to toggle the settings on the graph.

Everything:


WOT only


Anything out of the ordinary that you can read?
I'm hoping it was just the car reacting badly to the NOS octane booster.

Bonus:
While I had the chargepipe off, I stuck my scope into the manifold to see what my valves looked like. Showed it to my tech and he said it looks pretty good for 52k miles. This is the valve that looked the worst, too. N55 ftw!

[NathanIngrao]

Could be spark plugs. Do you have 52k on the same plugs? A tuned car is recommended to change plugs every 25k to 35k depending on how much you work the motor.