Vanos Rebuild Start Hesitation

[Slideways]

What about trying another DME?

[jamesfoley]

Then it's time to check injectors leaking and flow rate.

I do have a fuel pressure tester arriving in the mail in the next day or two, so plan on getting some solid readings on video of what that looks like.

Issue I have with doing injectors is it disables the car for a few days which I'd love to avoid if I can.

Might sound like a dumb question, I know leaking injectors can richen the mixture which would cause negative LTFTs, but why would they cause the fuel system to go into open loop fault? I would have thought things would have to be bad enough to throw a code.

The only other small things I've noticed with the car is that I sometimes feel like it surges if I put my foot down going from a low RPM cruise to pick up speed, almost like there is a lag in throttle input for some reason. The other is that when going up hill at low speed and low RPM, the car feels like it is doing a load of tiny surges, it just doesn't feel smooth.

But apart from the above, regular cruising around, getting up to speed, and wide open throttle all seem perfectly fine.

Faults wise I've had "094 Inlet VANOS adaptation" which was the VANOS being a tooth out on the inlet side and was resolved with having the VANOS timing re-done. I've also had "P0174 System Too Lean" when I re-fitted the new MAF, which I cleared and never saw again.

The following shadow codes only appear in P.A.Soft BMW Scanner and I have no idea if they are legit or not

• 089 Internal Fault
• 099 Internal Fault
• 050 Ignition coil, cyl. 4
• 025 Ignition coil, cyl. 1
• 143 Electronics-box fan

The above errors just appear randomly, sometimes they are there and sometimes they're not. Also the Ignition coil errors don't make much sense as I've had these codes both before and after I put a whole new set of coils in, and the code doesn't follow the coil if I move them around, unless these are the cylinders which have bad injectors? I can't find anything online about the internal fault codes though.

Just to keep a log it's worth mentioning that I pulled all the connections from the DME (with the battery disconnected) to check for oil in the plugs, but the DME box and all connections are dry as a bone.

Determined to get to the bottom of this...

[sapote]

We have proved it’s not MAF though.

No history with injectors, installed at factory and been there ever since is my guess…

Then it's time to check injectors leaking and flow rate.

[jamesfoley]

Please don't turn on the AC for the test. Do hot idle again to confirm MAF is around 4g/s at idle and not 6.
The cold log proves that the precat sensors are working perfect -- deep low during extra air from the SAP running, and switching normally after that.
I was hoping the cause of fuel status 8 was due to bad MAF of 6g/s at idle, until seeing that the AC was on.

If MAF is indeed around 4 at idle, then it will be a challenge to find out the cause of status 8 but blaming the leaking injectors.
What is the injectors history?

We have proved it’s not MAF though.

No history with injectors, installed at factory and been there ever since is my guess…

Annoyingly you can’t buy genuine injectors at the moment due to them being unavailable, so my only option would be to pull injectors and send them away to be cleaned which leaves the car unusable which would be a pain 😅

Buying bigger injectors and having them mapped in is an option, but an expensive one.

[sapote]

sapote Here is a cold and warm start log.

Cold: https://datazap.me/u/jamesfoley/e46-...d?log=0&data=2
Warm: https://datazap.me/u/jamesfoley/e46-...m?log=0&data=2

I cleared the adaptations before starting the cold log as you can see the long term fuel trims start at 0, but they do end up back in the negatives by the end of the warm log. Worth noting that none of the above starts where "hard", started on the key as expected.

Forgot to mention, A/C was on here which might explain the higher MAF rate.

Please don't turn on the AC for the test. Do hot idle again to confirm MAF is around 4g/s at idle and not 6.
The cold log proves that the precat sensors are working perfect -- deep low during extra air from the SAP running, and switching normally after that.
I was hoping the cause of fuel status 8 was due to bad MAF of 6g/s at idle, until seeing that the AC was on.

If MAF is indeed around 4 at idle, then it will be a challenge to find out the cause of status 8 but blaming the leaking injectors.
What is the injectors history?

[sapote]

I pulled PIDs to get higher resolution O2 sensor data, with all the PIDs the data rate is a bit slow. I'll get a couple more logs tomorrow though with all the PIDs back in. Currently using an OBDLink MX+ and the OBDLink app on my iPhone (which is basically OBD Fusion), not sure if there is a faster way to poll data.

Only things I've yet to replace now are the camshaft sensors, throttle position sensors, and injectors.

Needed PIDs: coolant temp, all 4 O2 sensors, MAF, fuel status1, fuel trims, rpm,
No need: time, car speed, ignition timing, power supply voltage, load, fuel status2 (exact image of status1) , intake air temp (we already know it's good)

[jamesfoley]

sapote Here is a cold and warm start log.

Cold: https://datazap.me/u/jamesfoley/e46-...d?log=0&data=2
Warm: https://datazap.me/u/jamesfoley/e46-...m?log=0&data=2

I cleared the adaptations before starting the cold log as you can see the long term fuel trims start at 0, but they do end up back in the negatives by the end of the warm log. Worth noting that none of the above starts where "hard", started on the key as expected.

Forgot to mention, A/C was on here which might explain the higher MAF rate.

[jamesfoley]

This log doesn't have enough data. Try it again with the same data as in post #77, but get one starting at cold morning in the 60s or lower. Then a warm with idling and driving.
However, the MAF looks good.

I pulled PIDs to get higher resolution O2 sensor data, with all the PIDs the data rate is a bit slow. I'll get a couple more logs tomorrow though with all the PIDs back in. Currently using an OBDLink MX+ and the OBDLink app on my iPhone (which is basically OBD Fusion), not sure if there is a faster way to poll data.

Only things I've yet to replace now are the camshaft sensors, throttle position sensors, and injectors.

[sapote]

Bit of a late reply, but just sorting things as soon as my wallet allows. Both pre-cat O2 sensors have been replaced now and produced this log: https://datazap.me/u/jamesfoley/e46-.../?log=0&data=1

I'm going to assume that because I still have fuel system faults I potentially have issues with fuel delivery, something between the injectors and the fuel pump?

Can also confirm it did nothing for my hard start issue.

This log doesn't have enough data. Try it again with the same data as in post #77, but get one starting at cold morning in the 60s or lower. Then a warm with idling and driving.
However, the MAF looks good with around 4g/s at idle.

[sapote]

Just adding these two datalogs

Drive from cold: https://datazap.me/u/jamesfoley/e46-...ta=2-3-4-10-12
Drive from warm: https://datazap.me/u/jamesfoley/e46-...ta=2-3-4-10-12

Both times the car started without hesitation, but the logs still have a lot of fuel status 8's. Only pattern I can see is the post cat O2 sensors dip mostly where the status 8's appear.

39C or 102F is not a cold engine. When cold I meant in the cold morning so we can see if the SAP pump is working and how the O2 sensors acting at old condition.

[jamesfoley]

Did you replace the pre cat O2 sensors?

Bit of a late reply, but just sorting things as soon as my wallet allows. Both pre-cat O2 sensors have been replaced now and produced this log: https://datazap.me/u/jamesfoley/e46-.../?log=0&data=1

I'm going to assume that because I still have fuel system faults I potentially have issues with fuel delivery, something between the injectors and the fuel pump?

Can also confirm it did nothing for my hard start issue.

[sapote]

Did you replace the pre cat O2 sensors?

[jamesfoley]

Another not so interesting update. I cleaned the ICV today just to see if I’d get lucky there, but from what I can tell it hasn’t made any difference. It was definitely very dirty, and not as free moving compared to after I cleaned it. Throttle response from idle is a litre snappier now if anything, and it bogs down less when pulling away. Unsure if adaptations need clearing?

At least it was an easy exercise to understand how much of a pain in the arse the plenum hose clamps are. I know they’re not technically reusable, but got away with reusing 3. The others were fused together and I had to break them to free them. Some generic jubilee clips work for now, I just made sure they didn’t interfere with the throttle. Will most likely replace these when the plenum comes off again…

[jamesfoley]

Checking the sensor is easy with a DVM, but monitoring with engine running must be done with a scope. Are you thinking the sensor is intermittently bad? I don't believe it because the fuel status is good at idle, and went bad during driving -- so why the sensor gone bad during driving and not idle, consistently as shown in the log files?

• Long crank
• Hard rough start
• Instantly stalling after starting
• Almost stalling when coming to a stop

All the above make me believe that I have a soft failing intake camshaft sensor, or perhaps someone has fitted an eBay sensor before my ownership. Almost as if the sensor is too weak to read the trigger wheel sometimes.

The shop that did the VANOS and fuel pressure regulator did say it sounds like a fuel delivery issue, but more along the lines of a blocked line. I figured if I had a blocked fuel line I’d have starting issues all the time, and misfires especially at WOT.

[sapote]

Sorry to bring this thread up again, but just wanted to ask if anyone knows if a drop in either exhaust or intake camshaft position signals would result in a fuel system state change?

Also wanted to ask if there was a way to monitor the intake cam position sensor without using an oscilloscope? Unless graphing the VANOS intake position like I was before in TestO is the way?

Checking the sensor is easy with a DVM, but monitoring with engine running must be done with a scope. Are you thinking the sensor is intermittently bad? I don't believe it because the fuel status is good at idle, and went bad during driving -- so why the sensor gone bad during driving and not idle, consistently as shown in the log files?