I believe the problem is due to the capacitors in the tach leaking
(electronically, not physically). I have replaced a tach in my Spit that would
go from 0 to 6000 and back constantly when underway at highway speed (e.g. 3500
rpm). The replacement was a used one and it still varies between 3000 and 4000
when the reading should be 3500. I have heard that you can replace the
capacitors but I don't know the values (I could get the book out to look a the
colour code) or the voltage rating, or the type.
If anyone has the info, I would appreciate also. Since these Smith's gages are
used in just about all BLC, there should be some universality between makes.
Vic Whitmore
76 Spitfire
Thornhill, Ontario
Reed Mideke wrote:
>
> I hooked up the stock tach on my sentra/spit conversion (white/grey
> tach wire to coil negative) It seems to work fine, except that higher
> than about 4500 RPM, it wavers. Engine speed is stable. This is similar
> to
> the effect you get if your alternator is producing too much voltage,
> but I'm pretty sure my chaging system is OK. My concern is that
> the original coil was ballasted (6 volt), but the new one is not.
> Anyone know if this affects the tach ?
>
> PS: The car is running great again. The missing problem was apperently
> either due to a bad distributor cap, or a leaking vacuum connection to
> the idle control circut. For those of you who have been asking for
> more details, I'll be dragging out the camera 'Real Soon Now'
> and posting some pictures and description on the web.
>
> PPS: I mentioned a swap meet at mini mania this past weekend. Well, my
> sources were not accurate. It's next month. Sorry.
> --
> Reed Mideke rmideke@interbase.com
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