Vanos Rebuild Start Hesitation

[sapote]

sapote Not sure if this is of any use? Pulled this using OBDWiz and my OBDLink SX cable as I figured it might be a little more reliable than bluetooth.

https://docs.google.com/spreadsheets/d/1S39r-gle4AkVZQbz0lgBFSDoG0dpXlXvp6goGoDOJQk/edit?usp=sharing

1. It's better to have MAF in g/s instead of lbs/min, and temp in *C and not *F. At 860rpm your MAF=4.9g/s which is high or over-reported value. This can cause too rich mixture. MAF should be around 4.2.
2. Your fuel trims show it's too rich - could be due to the MAF or leaking injectors. Leaking injectors can cause rich mixture during starting and hard start.
3. Pre cat O2 seem to be ok, but post cat o2 switched to low a few times; it should be mostly around 0.8

The log file was in view mode only and not allows me to insert graphs from the data. Change the protection or post it as CSV file type. I copied and changed to CSV but then the file was displayed as garbage data.

[jamesfoley]

1. It's better to have MAF in g/s instead of lbs/min, and temp in *C and not *F. At 860rpm your MAF=4.9g/s which is high or over-reported value. This can cause too rich mixture. MAF should be around 4.2.
2. Your fuel trims show it's too rich - could be due to the MAF or leaking injectors. Leaking injectors can cause rich mixture during starting and hard start.
3. Pre cat O2 seem to be ok, but post cat o2 switched to low a few times; it should be mostly around 0.8

The log file was in view mode only and not allows me to insert graphs from the data. Change the protection or post it as CSV file type. I copied and changed to CSV but then the file was displayed as garbage data.

But, if it was the MAF wouldn't the DME tell me something was up? I guess at least it might be an easy swap, but the amount of cash I've thrown at this problem now is getting silly.

Injectors has been a suspect only because its the only thing the DME can't really report an error for. Its also been last on my list as the car is my daily and pulling the injectors and sending them away is a bit of a pain in the arse.

I assumed post cat values were based on the condition of my cats?

I've attached the logs as a zip as I can't upload CSV files directly it seems. Alternatively if you request edit to the Google sheet I can grant you access, I just didn't want to make it publicly editable is all.

[sapote]

DME doesn't can't tell if MAF is over-reporting or not.
"I assumed post cat values were based on the condition of my cats?". Could be but I think it could be due to the rich mixture.
Use DATAzap https://datazap.me/ to convert your CSV file and post the link. It's easy for others to analyze the log data. Here is an example of the warm idle data:https://datazap.me/u/declamondo/log-...?log=0&data=10

[jamesfoley]

DME doesn't can't tell if MAF is over-reporting or not.
"I assumed post cat values were based on the condition of my cats?". Could be but I think it could be due to the rich mixture.
Use DATAzap https://datazap.me/ to convert your CSV file and post the link. It's easy for others to analyze the log data. Here is an example of the warm idle data:https://datazap.me/u/declamondo/log-...?log=0&data=10

Here are some Datazap links:

https://datazap.me/u/jamesfoley/e46-m3-town-driving?log=0&data=3-5-7-8

https://datazap.me/u/jamesfoley/e46-m3-warm-idle?log=0&data=3-5-7-8

https://datazap.me/u/jamesfoley/e46-m3-more-town-driving?log=0&data=3-5-7-8

The "More Town Driving" log does have a load of idle time at the start if thats of any use. Can always grab a longer log of needed.

[jamesfoley]

Yeah I mean it's been ~3 years for me at this point and I've learned to live with it. Doesn't affect performance, driveability, or reliability, is just annoying to know it doesn't have to be like this lol. I did try replacing the DME, no luck -- same behaviour on stock MSS54 DME and MSS54HP DME (with and without CSL airbox and associated tune). Also did FPR and vacuum line, and for injectors I initially tried cleaning, and then tried a totally fresh set since OEM Bosch was still available cheap back then. I hope you have a different experience, and/or somehow figure out something that I didn't!

I don't suppose you know the length of the vacuum hose needed to go from the air rail to the fuel regulator do you? I've tried to pick this up but BMW want to sell it in metres. Same for the "Corrugated metal tube"

[Tomba]

Wasn't there a thread on starting issues which pointed to the DMTL system? Fuel fumes would enter the manifold/plenum over time and cause rich mixture during starting. Check these valves and the one from the canister valve. I would personally remove them and plug them off at the manifold for testing purposes.

[jamesfoley]

Fuel fumes would enter the manifold/plenum over time and cause rich mixture during starting.

I have read a butt load of stuff on the DMTL system, but not 100% sure that matches my symptoms is all.

Car can start perfectly fine in the morning and drive around with zero issues. I'll then come home, turn the engine off and take the key out, wait like 2 seconds, put they key in and try to start and it will struggle, or stall. Key out and in again and it starts fine as if nothing happened.

However it will also randomly have issues on the first start in the morning too, key out and in and it starts as normal.

It's super random, and now with the VANOS sorted but not resolving this I'm back throwing parts at the car and crossing my fingers.

The rich condition sapote raised feels like the first time I might actually have some evidence its air / fuel related.

[Tomba]

Crank and camshaft sensors new and OEM?

[jamesfoley]

Crank and camshaft sensors new and OEM?

Crank is new and OEM, not touched cam sensors though

[Tomba]

Crank is new and OEM, not touched cam sensors though

Try to remove the camshaft sensors and hold the tip towards something metal. It should have a strong magnetic field. I experienced that some sensors from new* or old lose their magnetic strength by time or from (*3rd party) factory. Your engine will needs some time to rotate and cause enough magnetic field in the sensor to generate a good signal. I suspect that the exhaust one is for detecting the correct cylinder as that one has a missing slot in its trigger wheel. Just a thought, although it should be present all the time and not like you described.
Can you read ECU with Tool32? job, [status_geberrad_adaption] might tell us something.

[ATB88]

I don't suppose you know the length of the vacuum hose needed to go from the air rail to the fuel regulator do you? I've tried to pick this up but BMW want to sell it in metres. Same for the "Corrugated metal tube"

I ordered them from FCPEuro, who sent me a fixed length. I can not remember if I ended up trimming down the length they sent me. I do remember it being fairly easy to route and decide on length. (and FWIW I did cam sensors. part of me is hoping our problem is the same and you're able to get to the bottom of it here, but the other part of me hopes your problem is different since mine feels unsolvable at this point . either way, pulling for you!)

[jamesfoley]

Try to remove the camshaft sensors and hold the tip towards something metal. It should have a strong magnetic field. I experienced that some sensors from new* or old lose their magnetic strength by time or from (*3rd party) factory. Your engine will needs some time to rotate and cause enough magnetic field in the sensor to generate a good signal. I suspect that the exhaust one is for detecting the correct cylinder as that one has a missing slot in its trigger wheel. Just a thought, although it should be present all the time and not like you described.
Can you read ECU with Tool32? job, [status_geberrad_adaption] might tell us something.

I have INPA working so I'd imagine Tool32 would work, though never used it. I'll see if I can get the results for that job though when I'm next tinkering. I want to re-run a VANOS test at some point too.

I ordered them from FCPEuro, who sent me a fixed length. I can not remember if I ended up trimming down the length they sent me. I do remember it being fairly easy to route and decide on length. (and FWIW I did cam sensors. part of me is hoping our problem is the same and you're able to get to the bottom of it here, but the other part of me hopes your problem is different since mine feels unsolvable at this point . either way, pulling for you!)

Thats fair, part number is 64111368684 right? RealOEM lists a "Corrugated metal tube" (12517508831) alongside it with I'm assuming the hose goes inside of? Did you replace this too?

I really dont think its timing anymore as its not consistent so no real reason to change the cam sensors yet, I did have a random crank sensor code which is the only reason that got replaced.

[ATB88]

I have INPA working so I'd imagine Tool32 would work, though never used it. I'll see if I can get the results for that job though when I'm next tinkering. I want to re-run a VANOS test at some point too.




Thats fair, part number is 64111368684 right? RealOEM lists a "Corrugated metal tube" (12517508831) alongside it with I'm assuming the hose goes inside of? Did you replace this too?

I really dont think its timing anymore as its not consistent so no real reason to change the cam sensors yet, I did have a random crank sensor code which is the only reason that got replaced.

Yeah those PNs look right. Huh, so I did get the corrugated tube, which the vacuum tube does sit inside, it did not strike me as being metal though. Just black corrugated plastic. Picture looks right though. Anyway, the original vacuum tube itself on my car was clear and the replacement part was opaque black, but fit in and did its job just the same.

[sapote]

Here are some Datazap links:

https://datazap.me/u/jamesfoley/e46-m3-town-driving?log=0&data=3-5-7-8

https://datazap.me/u/jamesfoley/e46-m3-warm-idle?log=0&data=3-5-7-8

https://datazap.me/u/jamesfoley/e46-m3-more-town-driving?log=0&data=3-5-7-8

The "More Town Driving" log does have a load of idle time at the start if thats of any use. Can always grab a longer log of needed.

The data show these issues:
Fuel system status 8 happened many times during driving, it is bad. Status 2 or 4 is ok, but not 8 or 1. This indicates engine having fuel mixture issue. This is confirmed with rich fuel trim of around -10 total (LTFT + STFT).
MAF is around 5g/s at idle which is too high. I would try to swap with a known good working unit.
pre cat bank1 O2 seems a bit lazy old. The other 3 sensors are ok.

[sapote]

Why hard start? The DME cut down the fuel (negative 10 fuel trim) due to the rich mixture in the last drive. When starting, the DME used the last LTFT which was around -7 and this could cause lean mixture during starting and hard start or stall. So I think good or bad start is depending on the LTFT from the last drive before parked.