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Practical demonstration on how to install a missing teeth trigger wheel and sync?

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Hello everyone,

Currently struggling to get my car synced on a EMU Black using a 60-2 trigger flywheel and a VR sensor.

Audi 2.2 AAN turbo, stock hall sensor on the camshaft and custom 60-2 flywheel.

While i've seen the existing webinars on trigger troubleshooting and signals as how they should look like.

So this is what i've got at the moment:

PIC 1, the flywheel with the missing teeth 60-2.

1. This is the signal i've got initially (PIC 2) from the primary trigger

2. I've chosen in EMU Software a Pulldown 4k7 resistor and the signal became much better as you can see (still don't understand why?) (PIC 3)

While I have the secondary trigger (hall sensor on camshaft) signal displayed properly, I still don't get the synchronized status, which I guess doesn't allow me to get the spark and fuel.

I was also told that the secondary trigger signal should occur before the missing teeth on the primary trigger on the scope, is that right?

We tried to crank it and to check with a strobe but we don't get any spark or fuel, I have tested the outputs (spark and injectors) separately and they work fine.

My concern is that I did not count the First trigger tooth correctly when installing the crankshaft and that's maybe why I can't get it synced.

As you can see on the logs, I can not see the RPM as well.

Is there a practical demonstration/guide on how to correctly install the 60-2 configuration and what inputs are required in the EMU software in order to get it synced?

I should also mention that I am able to see my flywheel position through a gap between the engine and gearbox, so I guess it is possible to count the teeth again If I did it wrong first time.

But just to summarize, if I understand it right.

1. Set the engine to first cylinder TDC, count the nr of teeth from the gap (-2) to the VR sensor - that would be First trigger tooth

2. Trigger angle (counted in degrees?) would be adjusted based on what we see on the strobe.

Please correct me if I'm wrong, as I am really struggling to understand how to get it synced.

Thank you

Attached Files

You have secondary trigger type set to "Audi", this only works with the 135tooth crank as far as I know. Sec trigger should be set to "1 tooth".

I would turn the pull-up/pull-down off for the primary and I would expect the cam to need the 4K7 pullup.

thank you Adam, I'll give it a try.

Are you saying that I should not use a resistor for the primary trigger even though it did help me to get a clear signal based on the scope data?

Normally for a VR sensor you do not want any pull-up or pull down as it will tend to bias the waveform up or down. The problem with the ECUmaster scope function is it is only showing the signal after it has been processed by the VR conditioner and the micro so it does not give any indication on how the signal/waveform looks. All it can really do is show you whether the ECU is seeing the correct number of teeth or not - and their position relative to each other.

Both pic 2 & 3 show an acceptable pattern from my quick look.

Hi Adam, just letting you know that I was able to get spark and synced status after taking your advices, thank you so much. Also I did not use a resistor on the VR sensor but did set the filter from low to medium.

I will hook up an oscilloscope to watch the trigger pattern though on cam and crank sensor and I hope I will get a proper reading.

By the way, I will give it a try tomorrow to sync the ignition timing using a stroboscope while cranking. It is really difficult to access the crankshaft on the AAN Audi engine and see the TDC mark, can i use the camshaft instead and make a TDC mark? thank you

Ok I am getting tired now on making tens of tries with different changes in the primary trigger settings and no success on getting a proper reading on the stroboscope.

As I mentioned before, I do have a gap in between the gearbox and engine where I can actually count the teeth from the gap to the 1st cylinder TDC, which I've actually done again, as you can see in my slow-mo video.


I did count 13 teeth from the TDC to the missing teeth (gap).

Correct me if I'm doing anything wrong here.

Then, I did hook the oscilloscope to the 1st cylinder using a brand-new cable that I hooked up to the spark plug and the other end to the coil (as I am using coil on plug).

I could not match the mark on the flywheel I've done at TDC with the mark on the gearbox, I did set ignition lock on 0 degrees and the marks were done when the engine was at 1st cylinder TDC.

Then I decided to remove the front engine cover and to make a mark on the camshaft pulley and engine (again TDC on 1st cylinder)

The strobe was firing chaotically, basically it fired 3 times nowhere near the mark I was expecting and the 4th time it would fire somewhere near the mark.

I did also observe that if my battery goes below 12V charge, my strobe would not fire.

So I was charging the battery and giving it another try.

Based on the Scope log on the EMU (PIC 1), everything looks perfect, although I logged the Trigger error and cam sync error and I did see an unexpected missing tooth error.

What can cause this?

I do have an oscilloscope if this helps, please help me as I'm really trying to start the car for the 4th day in a row with no success.

Thank you

Attached Files

I had a similar problem when the VR crank sensor wasn't mounted square to the trigger teeth. I noticed it seemed to be off a few degrees, (sensor did not point directly to the center of the trigger wheel). I struggled to get a timing light to show consistent results, and my ECU reported missing teeth and bad pattern errors. I removed the bracket holding the crank sensor, and determined mounting bosses on the engine were at slightly different heights and needed to be shimed -- now the sensor was aligned, I got good timing signals, and the engine fired right up.

The engine has worked previously, but it took us about a week of cranking / backfiring / fiddling with multiple timing lights. The reason this happened was the engine was rebuilt, and the crank trigger re-installed that missed the shim. Once fixed, it's run perfectly and starts easily.

I suggest checking the sensor gap distance, polarity (rising or falling edge), and that the sensor is mounted in the proper relation to the trigger wheel.

I can't tell anything from your signal trace, you are zoomed in too far. Zoom out until we can see what the peak voltages (are there trigger settings in your software?). You should be able to see where the cam signal is relative to the crank missing teeth?

Thank you David for trying to help.

Yes indeed I was planning today to check the edge with an oscilloscope and also adjust the gap, if this wouldn't help then I will simply change the mounting place of the sensor I guess.

Here are the logs zoomed out.

Thank you,


Attached Files

If you can get us a capture with a real oscilloscope it will be helpful. The ECUmaster "scope" is not great for diagnosing VR trigger problems. From the "unexpected missing tooth" I would say possibly either the edge setting is wrong or the adaptive threshold is too high.

Ok guys we managed to start the car with these settings and I still can not understand how and why it worked.

Strobed 0-10-15 degrees and everything seems to work fine.

Can someone give a proper explanation how did we get

First trigger tooth - 57

Trigger angle - (supposed to be around 45-60?)

Also , can not find what is adaptive threshold, does it mean the ECU is adapting the arming threshold itself? How does it work?

Thank you

Attached Files

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