Hmm.. Just had my alternator replaced, and PTS is still around on
warm days (80+ F).
Dave Hall
72 MGB/GT
Jay Tilton wrote:
> Bert.Otten@nni.nl wrote:
>
> >But apart from this slight nuisance ;-) , I encountered some other
> >thing. When the engine revs above, say 4000 rpm, the tach starts to
> >swing wildly up and down sometimes reaching 0 and then again to 6000
> >rpm.
>
> Unfortunate past experiences in my 77B have led me to hypothesize that
> the Psychotic Tachometer Syndrome (PTS) is a sign that the alternator is
> just about fried; probably something to do with intermittent currents or
> big changes in voltage. Every time I've observed PTS in my car, the
> alternator stops functioning within a few days, and PTS doesn't return
> after installation of a freshly rebuilt unit. Your car with a known
> shot generator lends some support to this theory. See if it doesn't go
> away with a new generator.
>
> My tach also does some a similar number when I shut the car off while
> the cooling fans are going. It kicks from idle up to about 3000 RPM
> while the fans are spinning down. I think in that case, after cutting
> power to the fans they actually start working as DC generators, feeding
> current back into the system. There's a less pronounced effect with the
> heater fan. Fortunately that doesn't seem to be doing any damage to
> anything.
> --
> Jay Tilton | jtilton@vt.edu
>
>
dhall@vcd.hp.com
|