75 TS: Misbehavin'..FOUND IT!

[Lars Arvidsson <arvid@domain.elided>]

Hello out there!
I'd like to share this recently found knowledge.
This summer I had some problems with the engine,
At idle it worked perfect, but sometimes, when hot weather,
I pressed the gaspedal it acted like kangaroo, with clutch
pressed the rev was oscillating vigoursly. Release the throttle to
idle position and tried again, then the malfunction was gone.
And sometimes, when driving at constant speed, there was just no power
at all,
the enginge became totally cut-off with no response to throttle.
Pressing the clutch and letting the rev decrease to idle speed did it,
after that I
had power as usual.
Very annoying.
I never found it, it became atumn and the symptom dissapeared.

Today, I did some garage-work. Replaced the dist caps, rotors and
ignitioncables.  And I also took the butterfly apart, drained the
cooling fluid so
it could be removed from the intake manifold.  I recalled what David
wrote recently,
about the idle switch. I found that the lid of the switch couldn't be
prised off
without damaging the cover, so I made two small holes in the plasic
cover and sprayed
WD-40 inside. What came out was dark coloured. I'm not sure if it was
some kind of grease
that was supposed to be inside, or just dirt. Lower throttle axis
bearing leaking, letting oil-water mix
from the crankcase vent in?
But, the main point is, that after that operation the engine turned into
a kangaroo again, and I
could clearly hear that the switch one time out of five didn't say
"clic"
So, finally, I've found the cause for this summers misbehaving!
OK, maybe I've destroyed the switch but it was defenitively not good
before.

So, This is the behavour when the idle switch is bad, and
the switch can be failing intermittent and temperature depending.

Soon on the road again ;-)
Lars A
75 TS 1990

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