Car lurching / surging forward under light acceleration at highway speeds.

[romnation]

09 135i.

When accelerating lightly at highway speeds between about 65-85mph in the 2k rpm range (6th gear, automatic in drive mode), the car seems to hesitate and lurch forward and backward. If I add more throttle the problem goes away. No issues with WOT either. The issue seems to be getting worse and it actually triggered these 3 codes, although I can not get the car to trigger them again after clearing.

2D2E - Angle of throttle valve - intake pipe underpressure, correlation
30FE - Boost over target

I am using the JB4, but when I cleared the CEL, the jb4 set itself to map 0 (which is jb4 disabled) and the problem still remains, so I'm starting to think the issue may be something else and not the JB4. Anyone have any ideas?

No idea on injector versions, plugs and coils are fairly new, walnut blast was fairly recent, and this is HPFP #2.

[romnation]

Here is a video of what happens:

This is with steady throttle input. If you turn the sound up, you can hear the car hesitating.

[dsocold]

i have that same issue when getting on the throttle at times it sorta lurches with a slight rpm bounce to it and i have the same throttle angle code as well... 2d2e

09 135i as well


i have new plugs, coils, hpfp, lpfp stage 2, injectors index 12 40k on em, i think its related to something else completely

it has me thinking somethings wrong with our throttle body....

[romnation]

Originally Posted by dsocold

i have that same issue when getting on the throttle at times it sorta lurches with a slight rpm bounce to it and i have the same throttle angle code as well... 2d2e

09 135i as well


i have new plugs, coils, hpfp, lpfp stage 2, injectors index 12 40k on em, i think its related to something else completely

it has me thinking somethings wrong with our throttle body....

Is your car stock or are you running any tunes?

[ianc]

Boost leak would be my first thought...

ianc

[dsocold]

MHD stage 2+ 93 and e50 maps occured on V7 and V8

I for sure dont have a boost leak i checked every single connection thoroughly from my upgraded chargpipe to the diverter valves, intercooler and the whole deal.. BUT i do suspect that i may have a vacuum leak, and another funny thing is this happend to my car right after doing my oil filter housing gasket, and while i was searching online about this code I ran into a thread where the guy had the same code after doing his OFHG but he later learned that he forgot to connect the vacuum line going into the intake manifold, but i made sure that i connected all those lines going to the throttle body and manifold so maybe it's possible that I might have a split vacuum line somewhere. My car is not reaching boost target. The car is requesting 19psi and i am consistently getting 3psi less at wot. I will be replacing all vacuum lines as soon as i get a chance. The boost seleniods im assuming could also be a possible culprit but nothings for sure..

[rominun]

My car does the same thing. highway speeds and barely pressing the throttle will make the car lurch. I have a boost gauge and when the problem happens, the vacuum varies by about 10 psi. Im FBO with jb4 and once i removes the jb4 and tried mhd, the problem went away. Pretty stumped on this

[romnation]

Originally Posted by rominun

My car does the same thing. highway speeds and barely pressing the throttle will make the car lurch. I have a boost gauge and when the problem happens, the vacuum varies by about 10 psi. Im FBO with jb4 and once i removes the jb4 and tried mhd, the problem went away. Pretty stumped on this

Did this happen in Map 0 when you had the jb4 installed?

[rominun]

Originally Posted by romnation

Did this happen in Map 0 when you had the jb4 installed?

didnt try switching maps.

[Mr Gasser]

There are turbo vacuum lines that run over the front of the Valve cover and over the oil filter housing. I'd check those lines and all vacuum lines...the waste gate vacuum lines going to the intake manifold too. What kind of spark plugs are you running?

[romnation]

Does anyone know if the jb4 user adjustable settings apply when running in map 0? Could someone do me a huge favor and test this for me? An easy way to test would just be menu11, which adjusts pedal feedback. (This option is only available from the steering wheel controls.