MS coil packed 420A

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02-17-2007, 01:05 AM

#21

mazdasly75

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Quote:

Originally Posted by Al Hounos

I understand wasted spark, but doesn't the MS tach output read the same as waht you see in megatune? In other words, the same as it is reading from the CAS input, and NOT the spark output, which would read 1/2 speed as a 2cylinder?

I know what you're trying to explain. The CAS signal inside the disty is 5V actually. I don't think you can use this signal since it's a square signal, you would read 0.1V by a multimeter. Only an oscilloscope can read the square 5V peak.

yeah you're right about that I should ask this on msefi forum....

02-17-2007, 10:09 AM

#22

mschlang

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Quote:

Originally Posted by Al Hounos

As long as your MT tach is reading correctly, the tach output pin will read the same rpm.

Quote:

Originally Posted by mazdasly75

I don't think you can use this signal since it's a square signal, you would read 0.1V by a multimeter.

I think there is confusion between the terms "spark output" and "tach output". In post 18, you said that you built two tach output circuits usings VB921s to fire the coils. What you actually built were spark outputs. The tach output circuit (in my first post) creates a circuit to provide a signal to the tachometer. It has nothing to do with the circuits that fire the coils.

02-17-2007, 11:02 AM

#23

mazdasly75

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Quote:

Originally Posted by mschlang

As long as your MT tach is reading correctly, the tach output pin will read the same rpm.

I think there is confusion between the terms "spark output" and "tach output". In post 18, you said that you built two tach output circuits usings VB921s to fire the coils. What you actually built were spark outputs. The tach output circuit (in my first post) creates a circuit to provide a signal to the tachometer. It has nothing to do with the circuits that fire the coils.

Well, seems like I misleaded term, you're right though, the circuit that fire the coils, are spark outputs. I still got to build a tach output signal.. thank's for the clarification