ignition offset angle

[ironwill11]

Hello,

I have a bunch of threads on here regarding the ignition offset angle including what it means, and how to set it. I also watched a bunch of videos on youtube. I followed the information I got from these places and played around with the my MS2 tonight.

I believe I have got it now and as people have suggested: set up the ignition offset angle and move on.

I was wondering if anyone can look at the data I collected and verify if I got it right or if I am wrong.

This is the MSQ I used:

2016-11-10_21.52.20_trigger_17.msq

This is the datalog that I got from it (could not log the whole thing otherwise the file becomes to big to post on here):

2016-11-10_20.41.29_angle_17.msl

These are the two videos I took with my phone with the timing light:

Part 1: https://www.youtube.com/watch?v=AMQSGaBYLAw

Part 2: https://www.youtube.com/watch?v=HfIrPbbratA

Any help would be greatly appreciated

Will

[whittlebeast]

Your biggest issue right now is noise on your sensor grounds.

I learned this issue really early, you must have several things sorted out to get any EFI system sorted.

1) an absolutly clean crank and cam signal

2) an absolutly clean signal into the squirt from all of the basic sensors.

3) the timing, as commanded from the ECU, must match what is happening at the crank as reported from a non adjustable timing light at all RPMs. I do this by setting the timing table at say 15 degrees everywhere and then check that timing at the harmanic ballancer.

Once you have these three things verified, you can move on to tuning the motor.

Andy

[jsmcortina]

setting the timing table at say 15 degrees everywhere

That's the hard way. Use the "Fixed Timing" setting - that's what it is there for.

James

[jsmcortina]

I was wondering if anyone can look at the data I collected and verify if I got it right or if I am wrong.

As Andy says, your sensors have severe noise - suggesting that your sensor ground return is connected to power ground somewhere or similar.

You appear to misunderstand how to set the base timing though. We cannot tell anything about this from the log.

Set Fixed Timing to 20deg. Check timing with the strobe - it must be 20. i.e. THE SAME
Set Fixed Timing to 25deg. Check timing with the strobe - it must be 25. i.e. THE SAME

James

[ironwill11]

I was wondering if anyone can look at the data I collected and verify if I got it right or if I am wrong.

As Andy says, your sensors have severe noise - suggesting that your sensor ground return is connected to power ground somewhere or similar.

You appear to misunderstand how to set the base timing though. We cannot tell anything about this from the log.

Set Fixed Timing to 20deg. Check timing with the strobe - it must be 20. i.e. THE SAME
Set Fixed Timing to 25deg. Check timing with the strobe - it must be 25. i.e. THE SAME

James

Could it be an issue that the same ground that the sensors go to was used for the timing light? This was due to the length of the cables attached to the timing light.

I have two timing lights, a simple one and the dial back (purchased prior to learning on here about them). I set the fixed timing to 10 degrees advance. The trigger wizard was telling me to set match the timing light to 17 degrees. Using the simple timing light I could see it was advanced about 17 degrees (my balancer only has a 0 degree timing mark). So I put on the dial back light and found out that it was at 17 degrees. I figured that since my actual timing was 17 and the commanded was 17 that I was good. I kept the light on and revved it up and it did not drift at all.

Will

[billr]

Well, I'm half-way there; I talked you into getting a simple timing light. Now I just have to convince you to put the dial-back far off in a closet somewhere and not let add to the confusion. If you only have a mark at TDC, then set "fixed" and "cranking" timing to zero and use the simple light. See which way the timing is off, then change the trigger offset (or whatever it is called) about 5 deg. It doesn't matter which way you change that (increase or decrease). If the timing light now shows you are closer to zero, then keep moving the offset in the same direction. If, however, timing is now further from zero, then simply move the offset in the other direction. With just a few iterations of this process you can quickly get timing right on, then check that it is stable over the whole rpm range.

The big "gotcha" here is that the dizzy rotor needs to be pointed correctly to the desired cap tower, and that is a "moving target" as MS imposes vacuum and centrifugal advance changes. Did we discuss all this before, in another thread, using a cap with a window in it to confirm rotor positioning?

[jsmcortina]

With Basic Trigger and a low number for ignition offset you cannot go lower than that angle. So the OP can't set 0 deg.

Sounds like your timing is ok.

James

[billr]

Oops. Then I suggest a new mark at 25 BTDC or such that can be used for reference now, and in the future. That can usually be done fairly easily. Maybe only accurate to within a degree or two, but that is a lot better than nothing.

[ironwill11]

Well, I'm half-way there; I talked you into getting a simple timing light. Now I just have to convince you to put the dial-back far off in a closet somewhere and not let add to the confusion. If you only have a mark at TDC, then set "fixed" and "cranking" timing to zero and use the simple light. See which way the timing is off, then change the trigger offset (or whatever it is called) about 5 deg. It doesn't matter which way you change that (increase or decrease). If the timing light now shows you are closer to zero, then keep moving the offset in the same direction. If, however, timing is now further from zero, then simply move the offset in the other direction. With just a few iterations of this process you can quickly get timing right on, then check that it is stable over the whole rpm range.

The big "gotcha" here is that the dizzy rotor needs to be pointed correctly to the desired cap tower, and that is a "moving target" as MS imposes vacuum and centrifugal advance changes. Did we discuss all this before, in another thread, using a cap with a window in it to confirm rotor positioning?

Hey Billr,

Yes we did talk about this in another thread when I was not sure if it was a fuel or timing issue. You are the one that convinced me to get the simple light and I only used the dial back one now because of the issue of having one mark, it was guessing that I was at 17 degrees with the simple one but wanted to make sure. I think you mentioned something about getting tape for the specific balancer which would have different degrees on it. Where would I get something like that to make marks at other degree points?

Yeah we talked about the dizzy cap and I did cut a hole in it like you suggested (thought about getting a clear one but they were hard to find and I don't think it would help with all the wires on it anyway). I it is difficult with the amount of room I have but I shined the light in there and the rotor was pointing at the correct tower. Just did not know the exact position on the tower but I guess this is what the trigger offset is for. I will try and do it again and get a video this weekend when I have my cousin over helping me if you are interested in seeing.

Will

[turbo conversion]

You should be able to get degree tape from any performance shop.

If not you can get it from Jegs or Summit etc.

Get the tape and take the guess work out of the equation.

David

[ironwill11]

Your biggest issue right now is noise on your sensor grounds.

I learned this issue really early, you must have several things sorted out to get any EFI system sorted.

1) an absolutly clean crank and cam signal

2) an absolutly clean signal into the squirt from all of the basic sensors.

3) the timing, as commanded from the ECU, must match what is happening at the crank as reported from a non adjustable timing light at all RPMs. I do this by setting the timing table at say 15 degrees everywhere and then check that timing at the harmanic ballancer.

Once you have these three things verified, you can move on to tuning the motor.

Andy

Andy,

Thanks for the reply, going to be working on it tomorrow and take a test datalog. This is the first time I saw this kind of noise in the the sensors. Occasionally I would get small flucutation in the TPS about 3 percent, but nothing like this. I was wondering if it was because i used the same ground for the timing light and I was picking up power from the back of the alt. The only other thing that I can think of is that I tripped over the wire connecting the megasquirt to the laptop while trying to take video and watch the parameters in TS. Do you have any other suggestions of things to look for when looking for interferences? All the sensor ground wires are going to the same ground the whole way like the manual says.

[billr]

I don't think the trigger offset can be used to set the rotor/tower relationship, that is a mechanical adjustment made by how the dizzy gear engages the cam gear, and is often adjusted by the age-old "twisting the dizzy". That will effect what trigger offset needs to be to be correct, though, so this is going to be an iterative process in more than one regard. Isn't a simple missing-tooth crank wheel looking more attractive now.

The key thing about positioning the rotor is that you want it pointing at the tower as best possible when spark is both at minimum and maximum advance. That means a compromise, since spark may vary from about 0 - 50 deg. The cap with hole in it can make this reasonably quick and easy, but each time you change the rotor position, you need to adjust the trigger offset again. I'm assuming, of course, that your "basic trigger" wheel is locked in rotational position relative to the dizzy rotor.

[ironwill11]

billr,

I was able to get a video with my cousin of the hole in the dizzy cap. It looks spot on to me.

https://www.youtube.com/watch?v=lS4cDDyz6LU

Will

[ironwill11]

I did have another grounds wire on top of sensor grounds that that were connected to the intake manifold. I moved this ground in an effort to clean up the noise on the sensors. However, I noticed that the starter gear was all burgered up and grinding on my ring gear. So I have to suspend the running tests for now.

While I did have it running I did get to play with the offset angle with some marking tape and my simple light. I was able to get the fixed timing at 25 degrees and the actual timing to 25 degrees with a 13.5 degree offset. With the same offset I did the same thing at 20 degrees fixed timing. Also got 20 degrees with the light as well. Revved it up and it did not move. I am pretty confident that I am pretty close. Going to re-check once I figure out the noise issue though.

[jsmcortina]

While I did have it running I did get to play with the offset angle with some marking tape and my simple light. I was able to get the fixed timing at 25 degrees and the actual timing to 25 degrees with a 13.5 degree offset. With the same offset I did the same thing at 20 degrees fixed timing. Also got 20 degrees with the light as well. Revved it up and it did not move.

Sounds spot on.
Make sure you don't twist the dizzy and don't change that ignition offset setting!

James

[ironwill11]

Thanks everyone for your help.

Unfortunately I have not been able to do anymore tuning do to having starter grinding problems. Bought a brand new starter and that one makes horrible grinding noise every time it is cranked.

Will