[bartbes]

Originally Posted by Mixmaster

Mine seemed to correlate with a full tank of gas. I pulled the lpfp which I had replaced with a stage two bucketless and found the breather vent/ hose blue connection lose in the fuel and not connected to the top had. I reconnected and the issue has gone.

This is interesting.

Ik have had this issue for over a half year now and tryed everything tot solve it. Mhd reset, inpa reset, checked complete pressure system no boost or vacuum leaks, Dvs are good, new plugs injectors coils turbo's valve cover etc. The issue comes and goes. One thing i did not change is the breather valve that sits under the intake, usualy i can hear it ticking and today the issue returned so i will check it out tomorrow.

[blbrchnk]

I have this same problem. Anyone find a solution?

[335e92tx]

Originally Posted by blbrchnk

I have this same problem. Anyone find a solution?

Vanos?

Try switching banks with the solenoids
See if prob. Changes.

Log vanos angles sels have been replaced and upload to datazap.me

[blbrchnk]

I reset adaptations on everything through MHD and the problem is solved!!!!

[HawkeyeGeoff]

Originally Posted by blbrchnk

I reset adaptations on everything through MHD and the problem is solved!!!!

Yeah this solved my similar issue; if you notice the throttle plate doing weird things it's time to reset all adaptations.

[Masher]

Noticed this occurred alot for people who recently changed their spark plugs. Happend to me as well. Reset all adaptations seemed to help alot but would randomly here and there. I haven't had it in a while maybe ECU just needed to adjust after driving a while?

[335e92tx]

Originally Posted by HawkeyeGeoff

Yeah this solved my similar issue; if you notice the throttle plate doing weird things it's time to reset all adaptations.

Well, the DME causes the Tbody to do all kinds of weird stuff from about second2 really. .. but,, im getting to the point where I selectively reset adapts, in an effort to find out a little more about what's going on.. one of the more likely ones is gonna be vanos. They do all kinds of stuff with the intake at light throttle <2000.

[milfriez]

Suscribing to this.

I actually just posted this exact issue on the page also after you.

I've gone down

New HPFP
New High pressure sensor
New Low pressure sensor
pulled and gapped plugs (less than a year old)
Walnut blasted a year ago
New index 12 injectors all around

Reset adaptions yesterday, I could get some to reset, but on others INPA tossed some error about ECU_Condition or something along those lines. It looks like I can only reset a few of them, the rest error out.

[mj6234]

Just another note. I have 108k miles. Randomly started getting an oscillation/surging under light loads (like going down a hill in gear with foot barely on the throttle, or it was kind of "surgy" when taking off in 1st sometimes).

Reset throttle, intake air mass, load control adaptions and seems to be gone.

[IvanE66]

I am having the same problems that just started about a week ago so I haven’t done anything to fix the problem

[Jonah335]

Originally Posted by mj6234

Just another note. I have 108k miles. Randomly started getting an oscillation/surging under light loads (like going down a hill in gear with foot barely on the throttle, or it was kind of "surgy" when taking off in 1st sometimes).

Reset throttle, intake air mass, load control adaptions and seems to be gone.

Perfect description of what I'm experiencing. I will try this fix but let us know if you're comes back.

[wuoltk]

Finally happened to me after getting OEM plugs in Luxumburge. Resets are not having any noticeable changes. Also no codes thrown.

[Paanzerfaust]

Originally Posted by wuoltk

Finally happened to me after getting OEM plugs in Luxumburge. Resets are not having any noticeable changes. Also no codes thrown.

I had intermittent but very annoying surging/bucking/occasional stalling similar to described in this thread - I took my car in to the shop for something unrelated to that and they found that I had a leaking valve cover gasket that was dripping oil on to my cats so I had that replaced right away for fear of fire and after that the surging went away. From what I understand a leak in the VCG (or valve cover itself) can cause pressure differences that can potentially lead to your car doing all of that shit. Don't know if it's because the car is trying to make up for less pressure in there than it wants so it increases RPMS temporarily, or if it's just straight up because there's not enough in there for it to perform properly but it absolutely made a difference and my leak wasn't even huge.

[feuer]

Lamumba had same/similar issue and new MAP on intake solved it.

[Paanzerfaust]

Originally Posted by feuer

Lamumba had same/similar issue and new MAP on intake solved it.

Yeah, my local shop said they've seen all sorts of stuff cause it before but it seems to almost always be related to the pressure in the intake manifold in one way or another.

[Lamumba]

Originally Posted by feuer

Lamumba had same/similar issue and new MAP on intake solved it.

Yes, the one on intake manifold, not the one on charge pipe. Boost around 2-3 psi was acting kind of weird , jumping back and forth. As soon as it goes more than 3 psi car was stable.

[JimiP]

Had the same issue as described above - surging/oscillating/hunting under light load and light throttle (approx. <10%)..

Resetting adaptations in MHD resolved it for me..

[tylerboland01]

Had this issue a few weeks ago. Engine would randomly start oscillating between 900-1100rpm at idle, and the exhaust was incredibly rich. The problem would go away after i started driving.

Ended up being the front 02 sensors.

[torrque]

Resetting adaptations will only put a band-aid on a wound which is not healing under.... Root cause is something else and will come back from my experience.

[torrque]

Originally Posted by dpaul

Over the last few months my car has developed a very annoying oscillation/surging/bucking that only occurs at low throttle opening and at relatively low rpm.

The problem most commonly manifests when getting under way from a stop light. However, it does not occur every time.

Starting is normal, idle is very smooth (once engine is warm), WOT is fine, power if excellent and throttle response is normal once at speed. Since I have a manual transmission, the bucking can be finessed without too much trouble but it still bothers the hell out of me.

I managed to capture it on a log:
http://datazap.me/u/dpaul9/log-1491247383?log=0&data=17

As you can see, little oscillations are evident in short and long term trims, spark timing, throttle position and a few other parameters.

The car has had recent plugs, the coils were new about 3K miles ago and the injectors were replaced between 5K and 8K miles. VANOS solenoids are very new as are boost solenoids.

The problem is not related to the JB4 (which I've removed for the moment) nor any flash tune - I returned the DME to stock first using MHD, then using WinKFP, without any effect on this problem. All adaptations have been reset numerous times, using MHD and using INPA ,without any effect on this problem. Had both BMS OCC and RB externalized PCV but removed both for testing which had no effect on the problem.

I'm completely stumped.

Your throttle body position follows the rpm changes perfectly, so it seems that it is oscillating in the same fashion. Did you do a throttle body reset ?
I would suspect either throttle body or accelerator pedal sensor at this stage, check your logs...
Eliminate that first, then move on...

[fredcase]

Off brand vanos was my issue. Put some used oem in and it went away.

[924er]

I had this issue resolved when the dealer installed new software on my car. (Due to replacing a module). It was like a reset of some kind. It was like a brand new car after that. These DMEs can do funny things.