Reid,
I think that you will find that the reason the tacho is 'sluggish' on start
up has something to do with the fact that your ignition coil has a ballast
resistor and your tachos are electronic. When you start the car, the coil
gets a full 12V supply from the battery. As your tacho is an electric, and
takes its feed from the coil, it has a built in safety device that cuts
supply for a few seconds to prevent the tacho from being overloaded by the
higher coil voltage at startup. My TR7 tacho is the same.
If you have a mechanically driven tacho (cable from distributor) and this is
happening - you've got a problem with your tacho...
Regards
==
Phil Johnson
Coventry UK
Club Triumph (UK) Spitfire/GT6 Secretary
http://www.club.triumph.org.uk/
66 Spitfire4 Mk2 FC73949
77 TR7 ACG15216
77 TR7 ACG10378A Ongoing Sprint Conversion
----- Original Message -----
From: Simmons, Reid W <reid.w.simmons@intel.com>
To: <spitfires@autox.team.net>
Sent: 19 July 2000 23:00
Subject: Sluggish Tach
>
> Eric;
>
> I have had this exact same problem over that last several years of the
> tachometer needle being "sluggish" when the car is started. I know the
> tachometer will eventually give me an indication, I just have to wait 2 -
4
> seconds. I haven't as yet elevated this problem to "important" or
> "critical" so I have not done any troubleshooting on it to date.
>
> Reid
> '79 Spitfire (original owner)
>
>
> -----Original Message-----
> From: Eric A. Yates [mailto:eyates@enteract.com]
> Sent: Wednesday, July 19, 2000 2:14 PM
> To: spitfires@autox.team.net
> Subject: Re: Tachometer sticks
>
> I too have a "sticky" tach, although its behavior is different from yours,
> Jeff.
>
> My tach does not show anything when the car is first started up. It takes
> maybe 3 or 4 seconds before the needle jumps into action, and from then on
> it works fine. Seems like an electrical problem... as if my tach just
isn't
> getting any "juice" until a few moments pass after startup. But why then
> would it work fine after that? This behavior is not periodic; it always
> happens.
>
> On Jeff's problem, it sounds to me like his tach might literally be
> sticking, perhaps rubbing against something (tiny speck of dirt, who
knows)
> which catches the needle around where it points to 3200 RPM.
>
> Eric.
> '78 1500, Chicago
>
>
>
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