OK gang, I need some help from those of you who understand electricity. As you
may recall, I am experiencing a significant ignition miss that I am not sure is
due to a carburation problem or now, possibly, an electrical issue. It is bad
at idle, worse at 2000-4000 rpms, then still present but not as noticeable
above 4000. I have a Nissan electronic ignition and a very powerful spark box
(one that I can disable and have done so with no effect so I do not believe it
is of issue). My car has always had some "burbling" in the exhaust, but I
always attributed that to the nature of the engine. A couple of weeks ago,
after removing and replacing the engine and trans due to a bad trans bearing,
the car ran GREAT... no burbling for 2 days, smooth, better power, then it
suddenly was back to the burble. Now it is much worse. Question: Is it
possible that I have always had some kind of electrical issue that allows the
car to run but that throws in an occasional miss (and now a much more frequent
miss) that becomes less noticeable at high rpms, due perhaps to the engine
running faster so it is less noticeable, or the electrical system overcoming
the problem? Bad or weak ground? (I do have a ground to the starter as well as
the alternator, both to the frame, plus the battery to the frame on a bolt in
the trunk where the battery is... how can I check this?). Some kind of short?
Other symptoms: The starter will sometimes click, suggesting a bad connection
(this is a new starter and other starters have done it before as well); Two
months ago I had to replace a wire that lead to the ignition switch due to it
getting hot and causing a condition where the car would not run or would die
(hmmm), also replaced the switch which has always been an after market switch
(maybe 20 years ago the PO had a problem?). I have checked voltage at the
ignition box on the dizzy with the car not running and it is good (at least 16
volts). When running, the spark plug wires interfere with the signal enough
that I cannot get a goo!
d read o
n my multimeter to check the box or the voltage going to it. Checking spark
with a timing light seems to show a good, consistent spark on all 4, and timing
advances normally so I think the mechanics of the dizzy are working fine. I
just don't know enough about electrical issues, and am hoping that some of you
out there can direct me on how to do some testing, isolating or have
experienced similar problems. As always, your help is Greatly appreciated!
Greg Burrows
67 2000
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