Decel lambda issues.

BEAT_ITN54

Private
Aug 25, 2022
34
8
0
Been chasing an issue where decel lambda will act odd.

Have had injectors sent out and serviced. All came back with no leaks, proper spray pattern, flow consistent across all of them.

Bank 2 will lag to reach 234.95 and sometimes fluctuate just below it.

Bank 1 used to behave properly but ever since rerouting lines for external catch can it has started to fluctuating around 50-100 until first hard pull then it will go back to hitting full lean instantly off throttle. Bank 2 also behaves better after aswell.

Both banks seem better if decel take place during stronger vacuum above 4000rpm

All new 02 sensors. Have reset adaptions several times threw mhd and pro tool.

Cleaned valves with no change

smoke tested and pressure tested for leaks.

last insepction of turbos showed no signs of oil leaks or play.

No smoke on decel or under load but was chasing a decel smoke issue that was a faulty check valve so possible that it fouled sensors.

No misfires or hard starts timing corrections minimal underload.

Fuel pressure seems good

Afr hits target with fuel trims staying under +10 during wot

Leaning towards somthing to do with the pcv/crankcase system but kinda hitting a wall.

17t e45 23psi DI only
 

Jern54

Sergeant
Oct 18, 2019
301
1
184
0
Netherlands
Ride
E91 N54 335i
Same issue here on bank 2.
Swapped out DI and PI injectors without any change.
valve stem seals are bone dry.

Are you running on stock internals?
 

BEAT_ITN54

Private
Aug 25, 2022
34
8
0
Same issue here on bank 2.
Swapped out DI and PI injectors without any change.
valve stem seals are bone dry.

Are you running on stock internals?
Yes stock internals. Pretty much no oil consumption. Maybe half a quart over 5500km if really hard on it. No smoke even being completely catless. Iv noticed it reacts to vacuum regulation. Need to get a nanometer to set correctly. Have set it roughly to 3 inHg. Also have replace valve cover gasket. Valve cover has maybe 15k km
 

_Calle_

Specialist
Jul 7, 2017
52
24
0
Germany
Ride
e82 135is
same here.
Have new Bosch ADV, new OE index 12 Injectors, new OE valve cover.
Also smoke and pressure testet, low and high fuel pressure is on point.
No issues at all, everything is running fine.
But AFR don´t go higher than around 115 on both banks.

I have no future idea.
 

BEAT_ITN54

Private
Aug 25, 2022
34
8
0
same here.
Have new Bosch ADV, new OE index 12 Injectors, new OE valve cover.
Also smoke and pressure testet, low and high fuel pressure is on point.
No issues at all, everything is running fine.
But AFR don´t go higher than around 115 on both banks.

I have no future idea.
Mine has seemed to react to crankcase vacuum adjustment. Have high side with sealed check valve so I have a vacuum regulator. Getting it close to spec seems to resolve the issue for the most part. Sometimes lazy when cold but after first wot it seems to respond well. Have heard that worn injector bores can cause it aswell. Good compression so almost ready to pull and sell for LS swap lol
 

TrEuDaT

New Member
Aug 22, 2024
2
0
0
same here.
Have new Bosch ADV, new OE index 12 Injectors, new OE valve cover.
Also smoke and pressure testet, low and high fuel pressure is on point.
No issues at all, everything is running fine.
But AFR don´t go higher than around 115 on both banks.

I have no future idea.
Wassup buddy. Did you ever figure this out? My back 1 AFR only gets to 115 on deceleration after a pull. I replaced all the bank 1 injectors (even after verifying they weren't leaky), and still same issue. Any guidance would be greatly appreciated sir.