Tachometer issue?

[Jim Wright]

On Oct 13, 2006, at 5:37 PM, Ben Fenner wrote:

> Have you ruled out the possability that it's a failing clutch?
> You're not just experiencing slipage?

Yes, I'm sure that's not it.  My ears can tell what the revs should
be, there's a definite difference between 2000 and 4000 RPMs, and the
gauge is definitely reading much higher than it should when this
happens.

> You say the problem seems to go away after things have warmed up.
> That doesn't seem like any electrical, or sensor, or gauge problem
> I can imagine. That sounds like a mechanical problem, possibly the
> clutch slipping. But, the clutch should slip more while warm, not
> slip less. Is this happening at idle? Is it just a jumpy idle that
> smooths out after things have warmed up?

Ok, what I'm remembering is that it isn't happening from start up,
but the only times I've seen the tach reading high are shortly after
I start driving.  What first made me notice was I'd be driving, then
from the lower edge of my vision I'd see the needle drop suddenly
with no other perceptible changes in driving.  When I'd glance at the
gauges, they'd look fine.  It took a while after that of periodically
checking the tach to finally notice it reading high, and it would
just drop back when it felt like it.

Unfortunately my daily commute is only about 20 minutes long, so I
haven't really had much chance yet to see if it comes and goes during
the same run.

I may just have to swap parts from my project car (is it still a
project car if you haven't touched it in almost 3 years??) but
that'll have to wait until next weekend.