Vanos Rebuild Start Hesitation

[Shonky]

Owon HDS242(S) (and also 272, 2102, 2202) are quite capable self contained scopes starting around USD120. Might be a bit easier than a laptop + USB scope.

[jamesfoley]

sapote Shonky Yea, the Owon scope is what I was going to go for. I’m a complete noob when it comes to oscilloscopes though, I know how they work in principle but never actually used one. From the small bit of reading I’d done in the past I read that it’s worth the investment on one with a higher sample rate as it’ll be more useful in the future.

[Shonky]

Without turning this into a DSO discussion...

Just be aware they are fairly basic devices but I think they have a place in between multimeters (these Owon units also have an OK one built in that's separate to the scope section) and a proper scope. They are limited to fairly basic triggering and have limited sample/memory depth. The automatic measurements are just the basic ones. They can't do any protocol decoding eg. CANbus.

A 40MHz unit should be plenty for pretty much anything car related. The higher bandwidth is relevant if you may want to use for any more serious electronics. Many microcontrollers are 100MHz+ these days.

Look up Kerry Wong on Youtube for some good reviews of them.

I have a 100MHz Owon and it does the job although I've not really used it in a car environment yet.

[jamesfoley]

Without turning this into a DSO discussion...

Just be aware they are fairly basic devices but I think they have a place in between multimeters (these Owon units also have an OK one built in that's separate to the scope section) and a proper scope. They are limited to fairly basic triggering and have limited sample/memory depth. The automatic measurements are just the basic ones. They can't do any protocol decoding eg. CANbus.

A 40MHz unit should be plenty for pretty much anything car related. The higher bandwidth is relevant if you may want to use for any more serious electronics. Many microcontrollers are 100MHz+ these days.

Look up Kerry Wong on Youtube for some good reviews of them.

I have a 100MHz Owon and it does the job although I've not really used it in a car environment yet.

Thats cool, appreciate the advice. It will likely be a dedicated car scope as I have nothing else to use it for. Will pick one up with a set of back probes when my bank account recovers and give it a try.

[sapote]

Owon HDS242(S) (and also 272, 2102, 2202) are quite capable self contained scopes starting around USD120. Might be a bit easier than a laptop + USB scope.

Most portable standalone scope with screen too small and also lack many good features, and this is why I suggest to have a PC USB based scope. The Pico I use can decode many different serial buses such as CAN, USB, I2C, SPI, rs232, UART, etc. With the PC bigger screen and better resolution, the signal waveform is easier to analyze, and the waveform can be saved and shared. Portable scope is good for working on the field.

Your money can buy a better USB based scope as it reuses many function of the PC already has, as opposed to standalone unit.

[jamesfoley]

Your money can buy a better USB based scope as it reuses many function of the PC already has, as opposed to standalone unit.

I guess the downside here is I'll need a reasonable laptop, the one I use currently is pretty terrible.

Just wanted to add this log which has some chunky sections where the fuel status was 8 for a bit longer. Again, O2 sensors seem to just go to 0v during those sections, not sure if they just report 0v when in open loop? Its both sensors as well so can't be a wiring issue surely?

https://datazap.me/u/jamesfoley/e46-...0&data=1-2-4-5

Might be a silly question, but could I be having a engine ground issue or would I have more issues than what I have currently?

[sapote]

1. Again, O2 sensors seem to just go to 0v during those sections,
2. not sure if they just report 0v when in open loop?
3. but could I be having a engine ground issue

1. The mixture was on the rich side most of the time and this is why you have negative fuel trim, so maybe during status 8 moment the open loop injected fuel (based on the default look up table) was less than what the combustion needed, and so the exhaust gas was lean (0v o2 sensor). IOW, open loop is leaner than closed loop in your case.
2. No, DME doesn't force o2 value to 0v during open loop, as you can see the value changed during cold start open loop with SAP running.
3. I don't think so, as if it's then the injector should be weak with lean code. Also, the starter should be cranking weak or fails to crank.

[jamesfoley]

1. The mixture was on the rich side most of the time and this is why you have negative fuel trim, so maybe during status 8 moment the open loop injected fuel (based on the default look up table) was less than what the combustion needed, and so the exhaust gas was lean (0v o2 sensor). IOW, open loop is leaner than closed loop in your case.

Only reason I feel its weird is because isn't the range of the O2 sensors 0.1v to 1.0v? I didn't think they were supposed to go to 0v, but this is just me going off what I've read around the web. The graph makes it look like it's going open loop beacuse the O2 sensors are at 0v, however there are a handful of times where the fuel status is 8 and the O2 sensors are reading higher values.

3. I don't think so, as if it's then the injector should be weak with lean code. Also, the starter should be cranking weak or fails to crank.

That's a fair point, the car cranks fine every time and it's never failed to crank.

Also found this thread which you've replied to sapote which is extremely similar if not the same as what I am dealing with https://www.e46fanatics.com/threads/...sults.1304746/

[jamesfoley]

Bit of a boring update.

Got hold of a second hand set of injectors and had them cleaned. Fitted them today (which was a royal pain in the arse), reset all adaptations, and the car seems to run well. So far it has started first time every time with zero hesitation.

However, looking at a log I still have a butt load of points where fuel system status hits "8", and the fuel trims are creeping back into the negative again. I really hoped that this would have fixed it 😞

Here is a new log with clean injectors: https://datazap.me/u/jamesfoley/e46-...0&data=1-2-6-8

Still zero reported faults through generic OBD reader and INPA.

What was weird is that when I fitted the injectors, I removed the fuel pump fuse and cranked the engine to remove residual pressure. However it didn't start leading me to think it had zero pressure after sitting?

[jamesfoley]

Can confirm injectors did not change anything, still the same intermittent crank no start, or intermittent hesitation starting.

Pulled these codes:



I can understand injector and throttle position sensor codes as I had to unplug them to remove the injector harness.

The crankshaft sensor code however seems to have come back? I replaced the crankshaft sensor already so not sure why I am seeing this again...

Codes cleared and have been replaced with two Internal Fault codes that do not clear 🤷♂️

Looking at the OBD graph, are the O2 sensor readings and fuel system faults actually misfires?

[sapote]

E6	DME: Electric throttle: setpoint/actual value deviation

This should cause the limp mode, and you didn't see the engine light turning on?

"Codes cleared and have been replaced with two Internal Fault codes that do not clear 🤷♂️"
What does this mean?

Shadow codes could be just a momentary.

[jamesfoley]

E6	DME: Electric throttle: setpoint/actual value deviation

This should cause the limp mode, and you didn't see the engine light turning on?

"Codes cleared and have been replaced with two Internal Fault codes that do not clear 🤷♂️"
What does this mean?

Shadow codes could be just a momentary.

Nope, no limp mode or lights on the dash, figured it was just because I removed the plug for the throttle position sensor at the front of the engine.

As for faults I’m always left with:

63 [099] Internal fault
59 [089] Internal fault

Went for a 70 mile drive and have the log: https://datazap.me/u/jamesfoley/e46-...0&data=1-2-3-4

Looks the same as all the others. It didn’t throw any other codes after that other than the two internal faults.

[sapote]

63 [099] Internal fault
59 [089] Internal fault

these could be the key to the mystery -- DME program code is corrupted. Try to reflash the code or change to another working DME.

[jamesfoley]

these could be the key to the mystery -- DME program code is corrupted. Try to reflash the code or change to another working DME.

For what it’s worth these codes only appear together with no other codes present, and P.A.Soft BMW Scanner is the only tool that shows me these. I get nothing in INPA or DIS/GT1.

[jamesfoley]

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.