Hello all,
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.
I got the same reading at first with my S-10, then it ran sluggish. I have a clogged tailpipe, the catalytic converter will be replaced.
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 at times.
I had a similar problem and it turned out to be a wire.
This is a DIS system, is it not? Does the complementary plug also show problems ( OP indicated that it did not).
If it were an intermittent coil duo, then another plug should also show misfire.
I replaced the plug, and the wire that I broke. All is well. Now, how do I kill the engine light? Thanks.
I replaced the plug, and the wire that I broke. All is well. Now, how do I kill the engine light? Thanks.
** You read my hint well.
After a few drive cycles with no problems detected the MIL should turn itself off.
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