hello, all! happy thanksgiving :)))))))))
maybe someone can help me or offer suggestions.
i have a 1992 buick lesabre v6. nice car - 125,000 miles and have been told
it has a very good engine. i bought it from my brother's brother-in-law. he
only had it for a few years.
a few months back i experienced some misfiring/hesitation/bucking issues at
seemingly random times. i took the car in and was told the ignition wires
and spark plugs were badly mismatched, so they were all changed. i also had
the fuel filter changed which was an original. the car ran well but have
noticed the same problem, but a bit worse. as a note, it was taken to a
local firestone which has done very well for me over the years.
what seems to happen is more consistent: usually when the car gets to around
40 mph, it starts to run a little rough. if i accelerate through that, it
seems ok. at higher speeds, the bucking seems to come back more frequently,
usually under sudden acceleration. if i accelerate very slowly and smoothly,
the problem doesn't occur very often. i used to have the same problem with
my last car but it seemed to be occasional bad gas.
i notice the problem much more often when in overdrive vs "regular" drive
(3rd gear), so i've been driving it in regular drive. i tried different
grades of gas, the trusty fuel system cleaner, etc. at lower speeds (under
40) i hardly ever have the problem only at higher speeds.
a few other notes: the car never stalls, starts immediately, and has plenty
of power under acceleration. i did pull the trouble codes and i did pull a
code for a faulty knock sensor. i did some research and suspect this could
be at least part of the issue, but i don't know to what extent. can this
part cause the problems i am having? i know it is related to controlling the
spark function, so it's possible. i checked the tranny fluid and it is
ever-so-slightly dark, but i don't think anything to be concerned about. the
lever is fine. firestone suggested i do a fluid flush, but many folks have
suggested not, since i don't know if the fluid was routinely changed in the
past. all other fluids are fine (doesn't lose a drop of anything).
one final note ;) the rear brake seems to pulsate. i recently had the pads
changed by a friend. i'm "assuming" that the rotor(s) may be warped and need
to be turned (if that can be done). :) he said the rotor was smooth so it
didn't need it, but i still wonder if it is warped.
any help would be great, and thank you!