Ignition Angle Data Question

[Jughead]

Question for the Hex team.

From which sensor is the Ignition Angle data taken?  I am assuming it is the one just below the alternator, correct?

Have an interesting problem.  Bike is a 2005 1200 GS with a very erratic idle.  This is the graph of the Ingition Angle realtime values.



This is the graph of my 2006 GSA, that idles like clockwork.



What is interesting is that while his bounces all over, it is on the positive side of the scale.

Mine is stable, but on the negative side of the scale.


         
Problem Bike.                          My Bike.

Any ideas?

[StephanT]

I'll have to investigate where the hall sensor is that gives that signal...

just keep in mind that the timing is influenced by the knock sensor as well... so if those are wonkers... then that will influence the ECU's timing as it tries to advance or retard accordingly...

best,
Stephan

[Inspector Gadget]

Indeed, I would also look at the knock sensors;
These are piezoelectric elements I understand and we had our fair share of replacements to solve such issues.

[Jughead]

Update:

Turned out that one of the stick coils was supplying a VERY weak spark, creating the uneven idle.

I was intrigued as to why he didn't resolve the problem when replacing the stick coils with another set.  Turned out that one of those was also only providing a weak spark! 

Goes to prove the value of only using KNOWN GOOD components to swap out with.

[StephanT]

hmmm... so how do you propose one tests for a good spark signal... I've heard of a couple of people that have been having coil issues... especially on the earlier models that are now going on 7+ years...

any suggestions anyone?

best,
Stephan

[Jughead]

Unless one has the means of measuring the high voltage side of the coil, I guess one can only really compare with the spark on the other side.

Since there is no physical connection to the output side of the coil, no errors will be logged.  Measuring the voltage would have to be done by physically connecting to the output side.

[StephanT]

We are looking at a way to determine quality of combustion.. which will be a good indicator... but not will still not point directly to the coil...

[Flattwin94]

Center pin in the coil stick, diode,test for continuity from that pin and the spark plug end. Should only have continuity in one direction. That's how I tested when I was in the shop and had no new replacement to use. Replaced numerous coils but they seem to last longer the last few years.

[WayneC]

A "trigger" coil diagnostic would be rather handy to visually inspect spark at a plug or measure HT voltage with a clamp meter on the older bikes