Vanos Rebuild Start Hesitation

[jamesfoley]

what had been done to cause it no longer shows up at idle now?

Not sure anything has changed, looking through all of my logs I get fuel status 8's at all sorts of RPM, its never been just high RPM. Just seems to be when coming off throttle, so even little throttle inputs cause it.

[sapote]

“Edit: Looking back at older logs I can see fuel system status 8 at 850 rpm, so I guess it's just happening all the time”

what had been done to cause it no longer shows up at idle now?

[jamesfoley]

Can't get any air past the fuel tank breather, so assuming its normally closed until engine is up to temp it must be fine. Unless of course its intermittently sticky where sometimes its stuck open, but that might be a bit of a long shot.

I doubt these issues can lead to fuel system status 8 during high rpm as you have.

I agree that it might be unrelated, but the fuel system status and O2 sensors read like its misfiring, and EVAP issues can cause hard starts and misfires so figured it was worth checking. Logs also have the fuel system status of 8 at 1600 rpm so not just high rpm

Edit: Looking back at older logs I can see fuel system status 8 at 850 rpm, so I guess it's just happening all the time

Starting to wonder if I'm trying too hard to blame something complicated. Wonder if it's just a bad spark plug, or perhaps head gasket which I've been trying to avoid blaming.

Edit 2:

Just incase this is of any use, I took the car out on my usual test route with GT1/DIS hooked up for the misfire counter, got 0 on all cylinders 🤷♂️

Here is all the data from the DIS Diagnostics screen after the drive, might be useful for someone:

Diagnosis DIAGNOSIS REQUESTS (MISFIRES)

Misfire counter: ACTIVE

Current
Cyl. driving cycle:
1: 0
2: 0
3: 0
4: 0
5: 0
6: 0

Note:
Current driving cycle: number of detected misfires since engine start


Diagnosis DIAGNOSIS REQUESTS (THROTTLE POSITION)

Potentiometer, throttle position: 0%
Potentiometer, servomotor position: 0%
Voltage, potentiometer, at throttle: 0.35 V
Voltage, potentiometer, at servomotor: 4.37 V

EDK actuator, duty factor: 8.1 %

Control factor, charge controller: 0.996
EDK specification by DME: 0%


Diagnosis DIAGNOSIS REQUESTS (EDK ADAPTATION)

Adaptations:

Rise, pot. at throttle: 28.7 %/V
Rise, pot. at servomotor: 27.6 %/V

Throttle, leakage air: 2.6 kg/h

Pot. at throttle, zero stop: 0.34 V
Pot. at servomotor, zero stop 4.20 V

Maximum deviation between specified and actual
values of throttle position: 2.8 %

Counter, increased EDK duty factor: 0

Counter, controller activation: 17
Counter, controller deactivation: 2


Diagnosis DIAGNOSIS REQUESTS (SENSOR-GEAR ADAPTATION)

Adaptation, sensor gear, crankshaft:
1: 0 °/oo
2: -0.18 °/oo
3: -1.29 °/oo
4: -0.30 °/oo
5: 0.27 °/oo
6: -1.08 °/oo

Counter,adapt 'n,sensorgear,crankshaft: 65535


Diagnosis DIAGNOSIS REQUESTS (ROADSPEED)

Road speed: 0 km/h
Vehicle speed via CAN: 0 km/h
Cruise control: NOT ACTUATED

Engine speed: 887 rpm
Engine load: 22%
Power supply: 13.7 V
Ambient pressure (sensor in CM): 1013 mbar
Air mass: 22.25 kg/h
Relative opening cross-section from throttle and idle opening: 0.225 %
Duty factor, tank-venting valve: 12.7 %


Diagnosis DIAGNOSIS REQUESTS (BASIC QUANTITIES)

Duty factor, electric fan: 65 %
Clocking, electric fuel pump: 8.329 ms
Oil level: 104 mm
Tank fill level: 23 1


Diagnosis DIAGNOSIS REQUESTS (HFS)

Voltage value, air-mass flow sensor: 1.14 V
Air mass: 22.25 kg/h


Diagnosis DIAGNOSIS REQUESTS (AIR CONDITIONING)

Enable signal for A/C compressor: ON

A/C-compressor request: ON

Switch, air conditioning: ON

Air-conditioning system: INSTALLED


Diagnosis DIAGNOSIS REQUESTS (KNOCK ADAPTATION)

Knock adaptation, cylinder 1: -2.03 °cr
Knock adaptation, cylinder 2: -1.65 °cr
Knock adaptation, cylinder 3: -0.59 °cr
Knock adaptation, cylinder 4: 0.58 °cr
Knock adaptation, cylinder 5: -1.37 °cr
Knock adaptation, cylinder 6: -1.29 °cr


Diagnosis DIAGNOSIS REQUESTS (OXYGEN-SENSOR CONTROL)

Oxygen-sensor controller, cyl.1-3,
control factor: 1.005
Oxygen-sensor controller, cyl.4-6,
control factor: 0.992

Oxygen-sensor control
cyl. 1-3: ACTIVE
Oxygen-sensor control
cyl. 4-6: ACTIVE

Additive mixture adaptation
(idle) cyl. 1-3: -0.068 ms
Additive mixture adaptation
(idle) cyl. 4-6: -0.112 ms
Multiplicative mixture adaptation (part load)
cyl.1-3 -2.04 %
Multiplicative mixture adaptation (part load)
cyl. 4-6 -3.26 %

Note:
Values lower than 0% mean mixture leaning
Values higher then 0% mean mixture enrichment

Tank-ventilation adaptation, cyl. 1-3: 0.96
Tank-ventilation adaptation, cyl. 4-6: 0.97
Weighting factor, diagnosis
Fuel system, cyl.1-3: 1.00
Fuel system, cyl.4-6: 1.01


Diagnosis DIAGNOSIS:REQUESTS (IDLE SPEED CONTROL

Specified idle speed: 870 rpm

Idle controller: ACTIVE

Idle-speed control valve, duty factor: 36.18 %

Idle controller: -6.4 Nm

Adaptation, idle controller: 12.3 Nm

Adaptation, idle controller (A/C on): 3.6 Nm


Diagnosis DIAGNOSIS REQUESTS (OXYGEN SENSOR HEATER)

Shunt voltage, oxygen-sensor heater, before
cat., cyl. 1-3: 3.559 V
Shunt voltage, oxygen-sensor heater before
cat., cyl. 4-6: 3.569 V
Shunt voltage, oxygen-sensor heater after
cat. cyl.1-3: 3.676 V
Shunt voltage, oxygen-sensor heater after
cat., cyl.4-6: 3.676 V

Oxygen-sensor voltage before cat.,
cyl.1-3: 0.127 V
Oxygen-sensor voltage before cat.,
cyl.4-6: 0.695 V
Oxygen-sensor voltage after cat.,
cyl.1-3: 0.718 V
Oxvaen-sensor voltage after cat.,
cyl.4-6: 0.752 V


Diagnosis DIAGNOSIS REQUESTS (PEDAL-TRAVEL SENSOR)

Pedal-travel sensor, potentiometer 1:
Pedal-travel sensor, potentiometer 2:

Adaptation, pedal-travel sensor 1
zero position: 684 mV
Adaptation, pedal-travel sensor 2
zero position: 344 mV

Voltage, pedal-travel sensor 1: 693 mV
Voltage, pedal-travel sensor 2: 351 mV


Diagnosis DIAGNOSIS REQUESTS (STATUS)

Engine operating state: IDLE
Inertia fuel shutoff: NOT ACTIVE
Ignition-lock position 2: ON
Ignition-lock position 3: OFF
Brake-light switch: OFF
Detection, adhesion
(gear engaged, clutch not actuated): NO

Fuel pump: ON
Secondary-air pump: OFF
Secondary-air valve: OFF

DME enabling by EWS follows: YES
Air-conditioning system: INSTALLED


Diagnosis DIAGNOSIS REQUESTS (TEMPERATURE SENSOR)

Engine oil temperature: 91 °C

Outside temperature: 26 °c
E46: via CAN from instrument cluster
E36/7: from secondary control unit

Exhaust temperature: 192 °C
Intake-air temperature: 50 °C
Coolant temperature, engine outlet: 91 °C
Coolant temperature, radiator outlet: 76 °C

Voltage, temperature sensor, intake air: 2. 28 mV
Voltage, temperature sensor, engine outlet: 0.86 V
Voltage, temperature sensor, radiator outlet: 1.23 mV

Max. DME temperature: 63 °C


Diagnosis DIAGNOSIS REQUESTS (VANOS)

Inlet VANOS, actual value: 59.1 °cr
Inlet VANOS, pilot control by DME: 60 °cr
Inlet VANOS, adaptation: -4.4 °cr
Inlet VANOS, status, adaptation: ADAPTED

Exhaust VANOS, actual value: 1.6 °cr
Exhaust VANS, pilot control by DME: 2 °cr
Exhaust VANOS, adaptation: 4.2 °cr
ExhaustVANOS, status, adaptation: ADAPTED


Diagnosis DIAGNOSIS REQUESTS (SMOOTH RUNNING)

Cyl. Smooth running
(raw data)
1: -637 us
2: 835 us
3: 516 us
4: -353 us
5: 248 us
6: -133 us


Diagnosis DIAGNOSIS REQUESTS (INJECTION)

Diagnosis DIAGNOSIS REQUESTS (INJECTION)

No. of deactivated cyls: 0
No. of deactivated cyls. DME spec.: 0

Cyl. duration of injection
1: 2.161 ms
2: 2.038 ms
3: 2.354 ms
4: 2.081 ms
5: 1.976 ms
6: 2.098 ms


Diagnosis DIAGNOSIS REQUESTS (IGNITION)

Cyl. ignition angle
1: 21.5 °cr
2: 21.5 °cr
3: 21.5 °cr
4: 21.5 °cr
5: 21.5 °cr
6: 21.5 °cr


Diagnosis DIAGNOSIS REQUESTS (ADAPTATION IDLE SYNCH.)

Adaptation
Idle
Cyl. synchronisation

1: -20 µs
2: -128 µs
3: 150 µs
4: 26 µs
5: -66 µs
6: 41 µs
​

[sapote]

"Did just have another thought though, I don't suppose it could be EVAP related seeing as basically everyone I take it to said it sounds like fuel? I've seen the DMTL pump mentioned in some threads but as far as I know my car doesn't have this, just the activated charcoal filter. There is the fuel tank breather valve though that connects to the same pipes as the ICV..."
I doubt these issues can lead to fuel system status 8 during high rpm as you have.

[Tomba]

Why check everything again when you can do it with a VANOS test I made for Tool32?

https://nam3forum.com/forums/forum/special-interests/coding-tuning/34304-need-help-doing-vanos-test-with-inpa?p=35697#post35697

Also, reading the ECU with a small program won't affect your laptop. But we do can check if the calibration is untouched or modified.

http://www.msstuning.com/mssflasher.html

For the DMTL/EVAP. If these valves leak when closed, fuel fumes could enter the manifold when standing still and have bad starting issues as a result.

[jamesfoley]

I can flash your DME remotely if you want. We can make a copy first and then flash latest software to begin with.

Appreciate the offer. My laptop just about runs INPA without dying, so trusting it to flash my DME with someone logged in remotely is a big ask 😅

Car is hopefully getting booked back in for another VANOS timing triple check, I have an oil leak from where the VANOS meets the head so it needs to come off to change that seal anyways.

I'll look into picking up a better laptop I can use and then maybe hit you up Tomba

Did just have another thought though, I don't suppose it could be EVAP related seeing as basically everyone I take it to said it sounds like fuel? I've seen the DMTL pump mentioned in some threads but as far as I know my car doesn't have this, just the activated charcoal filter. There is the fuel tank breather valve though that connects to the same pipes as the ICV...

[Tomba]

I can flash your DME remotely if you want. We can make a copy first and then flash latest software to begin with.

[jamesfoley]

“guess the only issue I have is that the DME doesn't seem to like throwing codes for anything 😅”

I suggested to reflash or replace the Dme before.

Issue I have with buying a new DME is that they're expensive to begin with, and then I need to find someone to either clone my DME, or do an EWS delete. So overall it would be an expensive experiment

[sapote]

“guess the only issue I have is that the DME doesn't seem to like throwing codes for anything 😅”

I suggested to reflash or replace the Dme before.

[jamesfoley]

MSS54 is near to equal as MSS52 (used for S62) As S62 is V8 engine and has 2 banks and double VANOS these are used.

You have TestO, do you also have Tool32?

I figured it might have been for engines with multiple inlet/exhaust cams. Only reason I ask is the Exhaust bank 2 has an actual value that changes? Where it gets that reading from I have no idea...

I have EDIABAS ToolSet 32, assuming that's the same thing?

[Tomba]

My only question is what are the "banks" it is referring to here?

MSS54 is near to equal as MSS52 (used for S62) As S62 is V8 engine and has 2 banks and double VANOS these are used.

You have TestO, do you also have Tool32?

[jamesfoley]

Just to follow this up with a bit of data, here is a log of Inlet and Exhaust commanded vs actual positions. Pretty sure the Exhaust graph just looks bad due to scaling but the Exhaust position swings half a degree above and below the commanded, and Inlet swings up to a degree below commanded. TestO is pretty decent when it doesn't crash.

My only question is what are the "banks" it is referring to here?

[jamesfoley]

If the DME doesn't issue error code for the EX cam then it's acceptable. If the cam timing is bad enough to cause issue, then DME should have popped the codes.

I guess the only issue I have is that the DME doesn't seem to like throwing codes for anything 😅

Other than timing, is there anything else hidden in the VANOS that could cause issues and not present a code? I've read a couple of posts now of people who have had issues after a rebuild and mention wear on VANOS internals as a potential. There is also oil pressure at the VANOS which I could probably check? Suppose there is also the potential that there was an issue with the seal install

[sapote]

Intake cam actual position compared to requested are exactly the same, but my exhaust cam actual vs requested are out by a degree. Exhaust values jump around all over the place and are never in sync.

Can 1 degree on the exhaust cam be the cause of the issues?

This was picked up by another specialist after confirming fuel pressure was good.

If the DME doesn't issue error code for the EX cam then it's acceptable. If the cam timing is bad enough to cause issue, then DME should have popped the codes.

[oceansize]

Are mismatches expected at idle though? Inlet cam was rock solid 60 degrees with no variance, exhaust was flickering around a couple of degrees constantly almost like it was trying to adapt for the difference between commanded and actual but never being able to get them equal.

Is TestO the only tool I can graph the cam positions? Pretty sure the guys I saw used an Autel scanner which could graph stuff, but they're expensive it seems

Been a while but it seems like it is fine for the exhaust to fluctuate a bit while intake hangs steady, but perhaps someone else can confirm as it has been a year or two since I last data logged and took note. I have AutoEnginuity but it isn't cheap.