Dual Spark Ignition Output #2 Not working

alan_3301 · Post by **alan_3301** » Sun Mar 16, 2008 8:49 am

I've had microsquirt running on my project ducati with fuel only for a couple of weeks now, but recently one of the stock ignition modules stopped working, so now I'm letting microsquirt handle the ignition system.

I'm using dual spark, the latest V2.883j code, I'm pretty sure I have most of the settings in megatune correct. The problem is nothing is happening on IGN2.
I removed all the wires I didn't need from the harness when I installed it, so I didn't have unused wires dangling around causing problems. I just reinstalled the ignition output wires, so this is my first time testing them.

After playing with every ignition setting in megatune I could find, I opened up the case to have a look around. I tested between the 3 leads of the ignition drivers, and the resistance values between the 2 of them and are exactly the same.

I've tested the AC voltage with a multimeter coming from the timing pickups, and both show ~65mv at the microsquirt connector.
I have a scope, but It is a Heathkit from the 60s and I'm not sure how to use it

Included is my msq and a cranking datalog.

Thanks for any help!!

alan_3301 · Post by **alan_3301** » Sun Mar 16, 2008 9:30 am

a couple more questions.

Because I have an odd-fire engine, with 90 and 270 degrees between tach pulses, should the Delta T field have a high/low alternating number, or one constant number like I am getting now?

Is there any way to confirm the embedded code version in the microsquirt?
the docs say it should take seconds to update, but mine took about 15 minutes to update and verify the code. Does this seem right?

old guy · Post by **old guy** » Sun Mar 16, 2008 12:02 pm

The only thing I see in yor msq. is that you have your trigger set to rising edge. Try it with falling edge. Also try reversing the leads on your VR sensors.
In you ignition map you only have your rpm bins set to 6000 rpm. You need to change these because I am sure your Ducati will rev much more than that.

alan_3301 · Post by **alan_3301** » Sun Mar 16, 2008 12:28 pm

Thanks for the reply.
I had tried rising and falling edge, They both seemed to have the same effect at this stage of where I am at, but I guess I should leave it at falling edge.

I have the vr sensor leads connected according to what the stock ignition module circuit board had labeled for positive and negative, but I will swap them and see what happens.

I failed to mention earlier that I am using optoin and vrin2. If it makes any difference.

I hadn't even looked at my rpm bins for spark advance yet, was mostly concerned with getting spark on both cylinders for now. Thanks for noticing, I will update that when I get back on this.

I think it is time for me to do some research and figure out how to use this scope I have. That will probably be another project by itself...

old guy · Post by **old guy** » Sun Mar 16, 2008 1:14 pm

Why are you using opto in if you are using a VR sensor. This is the wiring diagram you should be using The original drawing had the VR + & - reversed. Also some of the wiring harnesses had these wires reversed. Make sure they are the same as the drawing.

alan_3301 · Post by **alan_3301** » Sun Mar 16, 2008 2:02 pm

I am using optoin because with vrin1 I would get unpredictable cranking rpms between 200 and 25,000 rpms.

It was recommended to me to use the optoin circuit instead, which cleared up my cranking signal perfectly.

I think the opto circuit is working just fine, as I have a pulse on ign1.
It's the ign2 that is giving me problems, I guess that is coming from the vrin2 circuit.

Ok thanks for that pic, I haven't confirmed the pin position on my harness yet, but I will soon.

old guy · Post by **old guy** » Sun Mar 16, 2008 4:04 pm

You might want to read this part again.

Quote:
Independent dual ignition: alternating tach pulses offset in phase are fed into the two ignition inputs and they produce two ignition outputs to separate coils. This can be odd or even fire - it doesn't matter because the pairs of input/outputs are independent. This would typically be used for a two cylinder motor. In this mode there can be No toothed wheel, No trigger return, and No EDIS. Also set the ignition ISR time mask=0, and the percent mask must be less than the smallest phase offset of the inputs. For example with an even fire engine the phase offset would be 50% so you would want to set the percent mask to no more than 30% to allow for accel/ decel.

You have your mask set to 50% which is for an even fire engine. I would try dropping the percentage and see what happens. I don't quite understand this setting, maybe Mat could clear this up a little.
I still can't understand why the opto circuit is working when you are using a VR sensor.
It also states in the above quote that with this setup you cannot use trigger return, which you have yours set at.

alan_3301 · Post by **alan_3301** » Sun Mar 16, 2008 7:41 pm

old guy, thanks for all the help you have been.

It turns out that the vrin+ vrin- wires were swapped in the harness.
Now I have good spark on both cylinders, but the ignition is still not setup right for running.

I will go with trigger rise.

percent mask must be less than the smallest phase offset of the inputs.

Would the phase offset be the trigger offset? If so, I would probably need the mask% to be close to 0.
Does this apply to negative offsets?

Thanks again!

I will also try vrin1 again to see if it works better my revised msq

old guy · Post by **old guy** » Mon Mar 17, 2008 6:21 am

Now that you have spark on both cylinders, what is the problem you have now?
You say you are going to try VR1 in. What were you using when you got spark on both cylinders.
This is just a guess, but going from the example that says an even fire motor is 50% I would assume that a 90 deg motor would be 25%.
Also I would try calculated instead of trigger rise.
Have you used a timing light yet to set your trigger offset.

alan_3301 · Post by **alan_3301** » Tue Mar 18, 2008 9:17 pm

My problem is that I can't adjust the trigger offset enough to fire near TDC.
Mask is set to 25% Trying calculated and trigger rise. Also trying rising edge and falling edge. All options give me a spark about 60 degrees retarded.
I can adjust the trigger offset and get closer, but it seems to have less effect the more offset i input. I tried positive and negative offset.

The only thing I haven't varied in my testing is spark output, but I'm pretty sure going high/inverted is what I need.

I'm out of ideas. going with -90 offset gets close. 180 offset is not as close. I need like 250 offset, but it won't let me.

What am I doing wrong? Does spark offset degrees translate to real engine degrees?

My engine spins counter clockwise, but I don't think this is an issue.