Analyzing crank position sensor and cam position sensor capture on a B6304T

[Cwazywazy]

According to VIDA, this particular engine does NOT have VVT for the exhaust.

That's in alignment with what I thought already but I brought proof.

3.2 na has intake vvt and vvl, nothing on the exhaust. 3.0 turbo has vvt on both cams but no vvl. If that helps.

 

[Meatball]

So, I took the picture of the cam from VIDA and my observation of the trigger wheel on the engine and I believe that this image represents the trigger wheel (lower left hand corner, I sketched the trigger wheel next to the cam).

 

[Meatball]

3.2 na has intake vvt and vvl, nothing on the exhaust. 3.0 turbo has vvt on both cams but no vvl. If that helps.

That is not what VIDA says. Not for this particular engine B6304T4.

There is only one cam phasor shown on the diagram for either of these engines in VIDA.

The NA engine has "Cam profile solenoids" and a VVT solenoid.

The Turbo engine has only the VVT solenoid.

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Again. We are trying to cross the Rhine and I am still trying to figure out how to disembark in Naples.

 

[Meatball]

 

[Meatball]

Also, it is time for me to go build a pressure transducer.

That was the suggestion from another resource. Use the pressure transducer to sync the cam. Then sync the cam and the crank (I only have a 2CH PICO but it can merge/sync waveforms from historical data)

 

[bobxyz]

I don't think that you understand what I am asking.

Correct, I certainly don't but I'll try again...

Does the "big gap" happen in relation to the 720* rotation when the lobes are in position to lift the valve.

The cam and crank sensor gaps (or teeth) are used for cam and crank position references. The ECU calculates everything from those position references. One of the cam teeth _might_ happen to be aligned with one of the 6 lobes, but it's not required. What is required is that the ECU has the correct calibration numbers (in degrees of rotation) for the crank 60-2 tooth gap and for the cam VVT phasing.

Let me try a high-level explanation for any modern engine and see if that helps with yours.

First off, the ECU must accurately know the position of the crank so that it can fire spark at the exact right time. The missing tooth section of the 60-2 crank wheel provides the reference. For the old redblocks, this is 87degrees BTDC. This may? be the same on your B6304T4 engine. You will need to find this value and enter it into the EcuMaster setup.

Once the crank position is known, an engine can run fine using either a distributor or wasted spark without any cam sensor. This was common up to the mid 1990s.

Next, in order to run full sequential ignition and fueling, a cam sensor is needed to tell the difference between power and intake strokes. Say that the #1 cylinder is at TDC. It could be at the start of the power stroke, or at the start of the intake stroke. The cam sensor, with a unique pattern, allows the ECU to determine (or sync) to the engine stroke. For example, from your original waveform, the wide cam pulse would occur during #1 power stroke and the narrow cam pulse would occur during #1 intake stroke.

I don't know what EcuMasters supports, but somehow you need to configure it with the unique cam pattern and how that relates to the stroke.

Finally, to add continuous VVT support, the ECU needs to know how much the VVT has rotated the cam. This is usually done simply by measuring the shift in the cam sensor waveform relative to the crank waveform. This means that the toothed pattern for the cam needs to on the inner portion of the sprocket, or simply an extra thin lobe on the cam itself. It should be obvious what's being used, sprocket or cam, based on where the cam sensor is mounted.

The ECU needs to be configured with the min and max VVT rotation of the cam, versus the crank missing tooth section. The EcuMaster VVT wizard may be able to figure this out automatically if VVT is disabled, or locked to min/max rotation.

 

[Meatball]

Correct, I certainly don't but I'll try again...


The cam and crank sensor gaps (or teeth) are used for cam and crank position references. The ECU calculates everything from those position references. One of the cam teeth _might_ happen to be aligned with one of the 6 lobes, but it's not required. What is required is that the ECU has the correct calibration numbers (in degrees of rotation) for the crank 60-2 tooth gap and for the cam VVT phasing.

Let me try a high-level explanation for any modern engine and see if that helps with yours.

First off, the ECU must accurately know the position of the crank so that it can fire spark at the exact right time. The missing tooth section of the 60-2 crank wheel provides the reference. For the old redblocks, this is 87degrees BTDC. This may? be the same on your B6304T4 engine. You will need to find this value and enter it into the EcuMaster setup.

Once the crank position is known, an engine can run fine using either a distributor or wasted spark without any cam sensor. This was common up to the mid 1990s.

Next, in order to run full sequential ignition and fueling, a cam sensor is needed to tell the difference between power and intake strokes. Say that the #1 cylinder is at TDC. It could be at the start of the power stroke, or at the start of the intake stroke. The cam sensor, with a unique pattern, allows the ECU to determine (or sync) to the engine stroke. For example, from your original waveform, the wide cam pulse would occur during #1 power stroke and the narrow cam pulse would occur during #1 intake stroke.

I don't know what EcuMasters supports, but somehow you need to configure it with the unique cam pattern and how that relates to the stroke.

Finally, to add continuous VVT support, the ECU needs to know how much the VVT has rotated the cam. This is usually done simply by measuring the shift in the cam sensor waveform relative to the crank waveform. This means that the toothed pattern for the cam needs to on the inner portion of the sprocket, or simply an extra thin lobe on the cam itself. It should be obvious what's being used, sprocket or cam, based on where the cam sensor is mounted.

The ECU needs to be configured with the min and max VVT rotation of the cam, versus the crank missing tooth section. The EcuMaster VVT wizard may be able to figure this out automatically if VVT is disabled, or locked to min/max rotation.

I have explained that I already know the things that you have repeatedly told me. Thank you for your time and effort.

Please read the following and understand:

"Again. We are trying to cross the Rhine and I am still trying to figure out how to disembark in Naples."

 

[bobxyz]

I tried to find the EcuMasters EMU Pro 8 documentation for configuring crank/cam triggers but couldn't find anything relevant. Maybe it's documented elsewhere, or is only available to purchasers? You'll need to find the detailed instructions for setting up a cam trigger, or cam sync, or secondary trigger - I'm not sure what term EcuMasters uses.

If all you're trying to do is determine the rough cam sensor pattern for power vs intake stroke, just install a spark plug in #1 and redo your crank/cam waveforms. It will be obvious where it's slowing down on the #1 compression stroke.

 

[Meatball]

I tried to find the EcuMasters EMU Pro 8 documentation for configuring crank/cam triggers but couldn't find anything relevant.

Bob, I'm gonna be honest with you. Their documentation sucks.

So far, I have gotten relevant information from the EMU Pro doc, the EMU Black doc, the ADU and several other manuals on their website. I actually have the software installed for the Pro, the Black and the ADU.

Part of this is my fault to be sure though. I bought the pro because it had just enough IO for me to keep 85% of the XC90 functionality.

I had to abandon the EVAP system completely though. There just isn't enough space on the header, Not unless I can reconfigure my spare spark outputs. But that is waaayyyyy down my list of concerns. Anyway, it is called the "Pro" for a reason. If you look on YouTube, by far the most commonly used systems from ECUMasters is the Black and their PNP series. Both of which are documented far better than the Pro. Probably because they assume that the Pro will be used by Professionals in the Motorsports industry. Again, they didn't sell this to me. I picked it based on it's IO capabilities.

 

[Meatball]

Also, progress:



A DIY transducer made from the high-pressure A/C switch on the donor S60

 

[Meatball]

It makes a nice correlation with the cam signal.



Now, I guess it is time to break out the Hantek. It has eight channels but much lower resolution also kinda janky software.

 

[bobxyz]

^^^ That's a great picture!!! I'm surprised how well the 3-wire A/C sensor works for cylinder pressure. Thanks for sharing

I installed the Ecumaster software on my junk laptop and looked briefly through the available configurations. The crank missing tooth alignment value goes into the "Trigger->Setup->First TDC" box. The cam alignment is under "Trigger->Secondary->Pattern". There's some brief help text available for each option, and one of the available options should work for your 2 tooth long/short pattern. I didn't see where the VVT alignment/range was configured, maybe it's only through the wizard?

What you need now is 3 pictures, each showing 720degrees of rotation, from a pressure peak to next peak, for:
- pressure and crank
- pressure and cam with VVT at one extreme
- pressure and cam with VVT at the other extreme

I'd use the picoscope with better resolution. Once you have the 3 pictures, you need to align them. I'd open each one with Paint, or your favorite photo editor, crop each picture from exact pressure peak to next peak, then resize to 720 pixels horizontally. This gives a scaling 1 pixel per degree of crank rotation. [With the pico scope resolution, you could try resizing to 1440 pixels or 1/2 degree per pixel.] Now paste all 3 cropped/resized pictures into a single picture.

Measure the first falling VR edge after the missing tooth section to TDC (peak pressure). This is the "First TDC" calibration value.

For the secondary trigger cam setup, I'll need to see the picture to pick which emumaster pattern algorithm will work best over the VVT range.

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You've said that it's a monolithic engine - are there any exposed pulleys that turn at crank rate? If so, you can manually align the engine to TDC (chopstick through a spark plug hole), then paint a crisp white line across the pulley and nearby fixed plastic. This will allow you to use a basic timing light with a ecumaster fixed 0degree advance setup to get the First TDC value exactly right. If the engine won't idle at 0deg adv, you can use a fancier dial-back timing light with the same white marks, but idling at a fixed 10 or 15 deg adv and the timing light dialed back by the same 10 or 15 deg.

 

[Meatball]

If you pull the seal for the crank and spin the engine over by the starter, it dumps oil all over the place.

I can only imagine how bad it would be with it running

 

[Meatball]

I am not going to be able to "get a waveform for the VVT.". I think what you mean is capture the crank vs cam correlation at full advance vs static?

Remember, I am doing this on a long block sitting on my garage floor.

Everything that I've done to get the waveforms so far has involved rigging it up with wire scraps and a bench top power supply. No ecu. In fact, I don't have a harness that I can plug and ECU into anymore. I used them both to create a custom harness that mates the XC90, the B6304T4 and the EMU.

Maybe I could use the function generator on the Hantek to try drive the VVT. But then I wouldn't be able to capture.

The PICO only has two channels.

 

[Meatball]

I don't particularly like this capture. I always struggle with the Hantek to get a meaningful capture. Practice makes perfect I guess...

 

[Meatball]

screw it. Imma hit that VVT solenoid with 5V (105% DC, lol) and see what happens.

edit:// Nope:

Pulse width modulation (PWM) signal
Utop = Ubat
f = 300 Hz
Pulse ratio 5%

 

[Meatball]

Here is a new picture of the setup. If you zoom in to the front of the engine, you will notice that I've pulled the seal out to turn the engine by hand with the special tool.

Also not that I have put cardboard underneath this thing because I was about to be washed away in a torrent of 5W-30

 

[bobxyz]

Without being able to drive the VVT solenoid, it may take some trial and error to get the secondary cam trigger setup correctly. This can be done after installing the engine and ECU. From your already posted waveforms, I can probably guess at an initial cam trigger configuration. If this configuration is wrong, the ECU won't sync, or may fire a wasted spark 360degrees off. Once the engine/ECU are installed, you can use the ECU's built in diagnostics / labscope to redo the crank/cam/vvt measurements before trying to start the engine.

If you can do a scope capture zoomed in to show the crank missing tooth section just before the pressure peak, the initial setting for the crank tooth #1 angle (called Trigger->Setup->First TDC in ecumaster setup) can be measured. This should be good enough to get the engine running, but I'm still worried that the pressure peak isn't sharp enough to measure with +/- 1 degree accuracy.

Edit: I just looked and MaxxECU has a downloadable basemap for a "Volvo T6 (VVTi, 1000cc injectors petrol)". It uses a custom decoder for the cam/home/secondary sensor, but it shows a normal 60-2 crank sensor setup with a 86 degree First Tooth Angle.

 

[GTJordan]

Without being able to drive the VVT solenoid, it may take some trial and error to get the secondary cam trigger setup correctly. This can be done after installing the engine and ECU. From your already posted waveforms, I can probably guess at an initial cam trigger configuration. If this configuration is wrong, the ECU won't sync, or may fire a wasted spark 360degrees off. Once the engine/ECU are installed, you can use the ECU's built in diagnostics / labscope to redo the crank/cam/vvt measurements before trying to start the engine.

If you can do a scope capture zoomed in to show the crank missing tooth section just before the pressure peak, the initial setting for the crank tooth #1 angle (called Trigger->Setup->First TDC in ecumaster setup) can be measured. This should be good enough to get the engine running, but I'm still worried that the pressure peak isn't sharp enough to measure with +/- 1 degree accuracy.

Edit: I just looked and MaxxECU has a downloadable basemap for a "Volvo T6 (VVTi, 1000cc injectors petrol)". It uses a custom decoder for the cam/home/secondary sensor, but it shows a normal 60-2 crank sensor setup with a 86 degree First Tooth Angle.
View attachment 35371

I believe this base map is for the 99-2006 T6, not the SI6 engine he is using

 

[Meatball]

I believe this base map is for the 99-2006 T6, not the SI6 engine he is using

Yeah, I've already looked at that map. I think that is more for the B6284T like Lankku has in his 245