Could be ignition, under acceleration and higher combustion chamber pressures
the plugs are harder to fire, so the HT voltage goes up higher on significant
acceleration compared to gradual acceleration, and the HT system could be
breaking down like leads, cap, rotor etc. My daughters car had this and I
diagnosed it by clipping a timing light onto each coil lead and the plug lead
and sharply opening the throttle, which was enough to induce the misfire. I
immediately saw that while the coil lead caused the light to flash exactly as
before, on the plug leads it became erratic and inconsistent with the misfire.
New cap and rotor solved the problem. If the flashing gets erratic on the
coil lead as well then it could be the coil or ignition LT circuit. Most
problems in the ignition LT cause the tach to flicker as well, but possibly
not the condenser.
It could also be carburation. If you can accelerate smoothly all the way up
on a gradual throttle but get hesitation with a larger throttle opening, that
sounds to me like a flat or weak spot in the carburation. If you get this
after changing things on the engine it could be you have the wrong profile
needle i.e. need a 'richer' needle at that position of the piston. But if it
has suddenly started without you changing anything it could be a vacuum leak
or the carbs out of tune. A vacuum leak would normally give you a higher idle
at a given idle screw setting, so if that is not the case you should be able
to ignore that.
PaulH.
----- Original Message -----
I can, if I chose accelerate smoothly up to about 5K revs in every gear-I
have done it only after experiencing what I am about to describe as my
trouble. If I am on the highway with OD engaged cruising around 3500RPM's if
is start to accelerate I experience a loss of power, the car hesitates and
only when I take my foot off the gas and let the revs drop can I then
accelerate-but only to about3600 RPM.
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