90q missing on cyl 5...ideas?

[Doyt W. Echelberger]

Orin.............Thanks for readjusting my understanding of those oxygen
sensor functions. I had it screwed up. Pushing the coil wire back down into
its base did make it run right again, and now I understand why. You
explanation is so neat.....unburned oxygen = too lean....sensor makes it
richer.....etc.

I really didn't understand how the oxygen sensor works. Thanks.

Doyt Echelberger
 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
At 10:56 PM 12/20/2001 -0800, you wrote:
> >
> > Hello Dave............Might be a bad wire. Also, make sure your ignition
> > wire from the coil is pushed down all the way in the neck of the coil. That
> > connector tends to creep out in small increments, and eventually the
> > weakest sparker starts cutting out, and the oxygen sensor starts seeing
> > rich unburned mixture so it leans everything down
>
>Actually, the O2 sensor doesn't understand raw fuel.  It sees all that
>excess oxygen that didn't get burnt at all and signals lean,
>resulting in a rich mixture for the other cylinders.  You can very
>rapidly foul plugs when this happens.
>
>and then the other
> > cylinders don't run right, and the owner starts wondering if the engine
> > will get him home. When you floor it, the mixture gets better and it runs
> > better, but not right.
>
>It runs better because it goes open loop and ignores the O2 sensor.
>Still not right because of the misfiring cylinder of course.
>
>Orin.