Spark

bambo2888 · #1 Thu, January 7th, 2010, 07:43 AM

So, I just installed my gryphon... and LOVE IT!

I noticed that I can monitor spark and set alarms if spark rates fall below a certain threshold.

Is there a way to monitor or detect if my spark plugs are going bad/needing replacement? If so, that would be awesome! What numbers should indicate a failing spark plug?

I mean, I know what a misfire and rough running feels like, but a more quantitative indication would be ideal.

Thanks!

PS-- That may be a dumb question.

***Jackpine*** · #2 Thu, January 7th, 2010, 09:17 AM

It's not a dumb question at all. I'm going to try to answer it using my somewhat "feeble" understanding and if I'm wrong, someone will correct me and I'll learn something!

I think, when you monitor spark, you are watching the "advance" that is taking place as you drive. This varies according to RPM, and maybe, load.

The alarm MIGHT be triggered when the spark advance is "pulled" due to detonation, but I'm frankly guessing here. I seriously doubt if this alarm has anything to do with bad plugs though. And, I don't know what you mean by spark "rate", unless you're referring to "advance".

However, if there's a misfire, you could get a "P0300 Random Misfire Detected" or a "P030#" code where the "#" is the cylinder number. So, if you set your alarm notification to alert you on ONE code (I think the default is three), you'd get what you're looking for.

- Jack

***Longshot270*** · #3 Thu, January 7th, 2010, 10:52 AM

I'm making an educated guess here. But I dont think you'll notice if there is a single bad plug by watching the spark reading. Like Jack said, that number only show the advance in timing. I've noticed that everything from RPM and APP to MAF readings can cause the timing to go all over the place. WOT can bring it down to less than 3˚ but while cruising down the road it can hover around 30˚-35˚. With a spread like that I would imagine it's hard to be sure. I bet that having one bad plug would show up more on RPM which you can obviously feel, but a rough idle can be caused by many factors. That would be an interesting idea to log the spark and idle before and after someone is going to change plugs for refrence.

bambo2888 · #4 Thu, January 7th, 2010, 02:16 PM

Quote:

Originally Posted by longshot270

That would be an interesting idea to log the spark and idle before and after someone is going to change plugs for refrence.

good call. maybe i try to start logging some data, for im planning on taking the dive soon here with the lisle tool and tsb.

***Longshot270*** · #5 Thu, January 7th, 2010, 02:32 PM

Quote:

Originally Posted by bambo2888

good call. maybe i try to start logging some data, for im planning on taking the dive soon here with the lisle tool and tsb.

Cool, just dont forget to have different kinds of driving in similar conditions. I usually do one slow acceleration and then one WOT. That way you get a wider range of data. It also helps to make a second session later if your able (for verification). And on the PID's pick the most valuable 5. Here are 4 that are usually pretty important SPRK, RPM, MPH, LOAD and either APP, CHT, IAT, MAF, and AFRP for the 5th.