The tach in my Midget barely moves at all in response to the engine RPM.
How would I know if the loop is the right size? How does the size of the
loop affect the reading? It seems like an awfully inaccurate way to
calibrate the thing. My car originally had a mechanical tach and the PO
put an electric in the dash but there was no "doohickey" on the back so I
had to go picking through the carcasses behind my local LBC shop to get
one. I have converted the tach to Neg. ground, and carefully reviewed the
drawings as to direction of the loop, orientation of the doohickey, and
wiring connections. Now, while the tach twitches a little in
acknowledgment of the fact that the engine is running, the results are
most unsatisfactory. Any suggestions?
Phil Vanner
Mk1 Midget
-----Original Message-----
From: Syd Saperstein [SMTP:tcsyd@ix.netcom.com]
Sent: Tuesday, October 07, 1997 10:08 PM
To: Les Gould; mgs@autox.team.net
Subject: Re: Tachometer
I had a '67 "BGT and when I redid the tach for neg earth I learned that
the
size of the wire loop that goes though the "pickup" sensor block in the
tach was critical. (It should not make any diff. about pos or neg earth,
it's just that that's what brought me to the subject) If the loop is not
exactly the right length or size the tach will not read accurately and
seemed to read in multiples of the true rpm. I suggest you check that
loop
and how it sits in that little sensor block doohicky (that's a very
technical term I reserve for items electricum)
TTFN
TCSYD
----------
> From: Les Gould <lesgould@gti.net>
> To: mgs@autox.team.net
> Subject: Tachometer
> Date: Tuesday, October 07, 1997 7:24 PM
>
> Hi All- I have a '67 MGB with "positive earth". The tach will not go
any
> lower than about 3,000 RPM no matter how low I set idle. Is there
> anything to be tried besides rebuilding the tach? And if it must be
> rebuilt, can I do it? (I can rebuild a player piano!) And, if it must
be
> sent out, any recommendations as to where, or to whom? TIA, Les.
>
> 67MGB-hope to have it on the road soon
> 77MGB-hope I live long enough to see it on the road
> 61Sprite-wish I hadn't traded it in '66
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