Cold Start Rough Idle

El Supracabras · 06-01-2011, 07:04 PM

The secondary winding can only be checked using an oscilloscope as far as I know. There is also a device that measures Kilo volts using an inductive clamp somewhat like a timing gun. Though i'm not really sure if it will tell you if the coil is bad, only that there is increased or decreased resistance to current inside the cylinder. I'm sure someone here knows more about it than myself. Hopefully they will comment. Definitely one of those cases where having a known good part to swap or compare would be useful.
You shouldn't use the "feel" method especially with a computer controlled car. The computer can change the "feel" by adjusting fuel and timing to compensate for discrepancies (issues, driving habits) even while you drive. They are surprisingly active little boxes for the technology. The only way to know for sure that the timing is correct is to actually check it which is very easy. It may not be the cause of your problem, but it would be free to eliminate it as a suspect. Also make sure the crank pulley is in good condition, a worn and shifted pulley will throw off the timing mark.

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06-01-2011, 07:04 PM	#12
El Supracabras 3" Exhaust Join Date: Feb 2010 Location: Chicago Posts: 240	The secondary winding can only be checked using an oscilloscope as far as I know. There is also a device that measures Kilo volts using an inductive clamp somewhat like a timing gun. Though i'm not really sure if it will tell you if the coil is bad, only that there is increased or decreased resistance to current inside the cylinder. I'm sure someone here knows more about it than myself. Hopefully they will comment. Definitely one of those cases where having a known good part to swap or compare would be useful. You shouldn't use the "feel" method especially with a computer controlled car. The computer can change the "feel" by adjusting fuel and timing to compensate for discrepancies (issues, driving habits) even while you drive. They are surprisingly active little boxes for the technology. The only way to know for sure that the timing is correct is to actually check it which is very easy. It may not be the cause of your problem, but it would be free to eliminate it as a suspect. Also make sure the crank pulley is in good condition, a worn and shifted pulley will throw off the timing mark.