[Vik778]

So last night I was driving around the empty streets of NYC, having fun of course, exhaust getting pretty hot. I get off the highway, and as i leave from a light, 1st gear to around 2.5k rpm no problem, shift to second, give it about 20-30% throttle at 1500rpm, and for about half a second the engine basically cuts ignition/chokes/shuts off and turns back on and continues accelerating. So my first reaction is to give it more throttle in 2nd and see if it happens again, nothing. I do a pull in 2nd at wot to about 5-6k rpm, no issues, car runs fine. So then at the next light I shift to 2nd at low rpm once again, also apply about 30% throttle, and once again it does the same bogging thing under 2k rpm, once it passes that point, runs fine. After the second time it happened I got worried, turned on jb4 log and gauges and watched them as I repeat the same motions, but this time the car runs fine through low RPMs in 2nd and 3rd gear and hasn't done this since. No codes, idles fine. Does anyone have an idea of what this can be? I was guessing maybe something o2 related, since I got the exhaust pretty hot, and as it cooled down the issue went away, but hoping to find someone with more experience to chime in.
Other things I think might be related: I have a 4 bar tmap that sometimes throws a code and limp during start up when car is warm, I have never cleaned vanos, never changed o2s, never done a walnut blast, and I have a 3.5in catback(lowers back pressure when turbo is not active, such as at extremely low rpm). Plugs and coils are new. Car is FBO no inlets, 86k miles.
Thank you for taking your time to read this post! I don't post often since most of the answers I look for can already be found, but this was a weird one.

[mkolankowski]

I had the same exact problem it was my jb4. I removed it flashed an MHD map and the car has not done it since.

[Vik778]

Originally Posted by mkolankowski

I had the same exact problem it was my jb4. I removed it flashed an MHD map and the car has not done it since.

Hmm, for some reason I dont even question that it could be the jb4 lol, I am BEF with mhd tho, but will see, will disable jb4 and see if it changes anything.

[mkolankowski]

I was the same it had a bef with the jb4. I put it in map 0 i was still get the same issue just not at much. I removed the jb4 completely and the problem went away.

[Saif2018]

Originally Posted by Vik778

So last night I was driving around the empty streets of NYC, having fun of course, exhaust getting pretty hot. I get off the highway, and as i leave from a light, 1st gear to around 2.5k rpm no problem, shift to second, give it about 20-30% throttle at 1500rpm, and for about half a second the engine basically cuts ignition/chokes/shuts off and turns back on and continues accelerating. So my first reaction is to give it more throttle in 2nd and see if it happens again, nothing. I do a pull in 2nd at wot to about 5-6k rpm, no issues, car runs fine. So then at the next light I shift to 2nd at low rpm once again, also apply about 30% throttle, and once again it does the same bogging thing under 2k rpm, once it passes that point, runs fine. After the second time it happened I got worried, turned on jb4 log and gauges and watched them as I repeat the same motions, but this time the car runs fine through low RPMs in 2nd and 3rd gear and hasn't done this since. No codes, idles fine. Does anyone have an idea of what this can be? I was guessing maybe something o2 related, since I got the exhaust pretty hot, and as it cooled down the issue went away, but hoping to find someone with more experience to chime in.
Other things I think might be related: I have a 4 bar tmap that sometimes throws a code and limp during start up when car is warm, I have never cleaned vanos, never changed o2s, never done a walnut blast, and I have a 3.5in catback(lowers back pressure when turbo is not active, such as at extremely low rpm). Plugs and coils are new. Car is FBO no inlets, 86k miles.
Thank you for taking your time to read this post! I don't post often since most of the answers I look for can already be found, but this was a weird one.

Could be the JB4 but I wouldn't give it much throttle under 2k,its almost off boost completely. I'd say 2.5k or downshift to a lower gear before giving it the beans. lol

[isN54]

Has anybody reached out to @BugerTuning for a solution to this???
I have had the Jb4 for over a year I think and have not had this
issue until recently when I updated the software. It’s really annoying
Especially when you are cruising and need to give a little throttle to
get up an incline.

[Saif2018]

Originally Posted by isN54

Has anybody reached out to @BugerTuning for a solution to this???
I have had the Jb4 for over a year I think and have not had this
issue until recently when I updated the software. It’s really annoying
Especially when you are cruising and need to give a little throttle to
get up an incline.

It's mostly MHD users here, your better off posting on N54Tech