2000 LeSabre w/3800 @151K. Service light came on and I headed to
Autozone for the computer readout. #3 cylinder mis-fire. The coil wire
sparks, as does the plug wire at the plug. The plug is a nice tan
color at the tip, although I didn't check to see if it was sparking.
Is there something else I might want to look at as well? Thanks.
Lot's of things to look at. Could be that the plug isn't firing under
compression, Could be that it only breaks down under load, Bad injector,
bad compression, broken ring, bad intake allowing water into the hole.
I would toss it onto a scope and look at what the ignition is actually
doing. Run a comp. check dry/wet to see if it's in the hole. Once you
rule out those then it's time to get serious.
If the car idling at 700 RPM can you see each individual spark on that wire?
You've counted them and missed none? The visual of a spark stopped being
meaningful after the 1970's or so.
It may be the coil or the wire itself causing an intermittent problem. If
you distrust the computer, clear the codes and wait a week or so and check
it with another meter. If the misfire is serious, you will start to feel it
I had a similar problem and it turned out to be a wire.
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