Peter :
Your 6 cylinder, 4 cycle engine fires 3 times per revolution (each cylinder
fires every other revolution), so the RPM should be 20 times the frequency
in Hz. (eg 1200 rpm = 60 Hz) .
However, depending on your DMM, you may get multiple counts per spark (the
waveform on the coil is messy), which should be pretty obvious (reading 2 or
3 times what you expect).
Randall
> -----Original Message-----
> From: owner-triumphs@autox.team.net
> [mailto:owner-triumphs@autox.team.net]On Behalf Of Peter Zaborski
> Sent: Tuesday, October 05, 1999 12:25 PM
> To: 'TR6 List'
> Subject: electric tach question
>
>
>
> I have a question for those on the list who have some
> automotive electrical
> knowledge...
>
> I have a multi-function digital multimeter which has a
> frequency function.
> It measures the frequency as cycles per second (Hz) based on
> (I think) the
> pulses it gets from whatever source it is hooked up to.
>
> I hooked it up to my TR6 coil's negative post while the
> engine was running
> to try to verify my mechanical tach (car has the stock
> engine, stock Lucas
> distributor and aftermarket Ingnitor electronic ignition
> module -- I think
> this is a single spark ignition module). I did get some readings which
> appear useful. However not wanting to jump to any
> conclusions, I wonder if
> anyone who knows about such things cares to describe what
> readings I should
> have gotten in cycles per second connected to the coil's
> negative post.
>
> Looking forward to any replies.
>
> --- Peter Zaborski CF58310UO ---
>
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