blue

I would like to know what exactly goes bad in an opti and the likelihood of each factor well enough that I can know for sure at last. I've read a great deal of threads about the optispark but there's no thread I've seen that is precisely about what goes bad in it. I was looking at http://www.charm.net/~mchaney/optisprk/optisprk.htm and was wondering for one thing, why the rotor would ever go bad? Isn't it just an entirely mechanical object with a piece of metal on the end and a wire running its length? So why in the previous posts have many said that the cap or rotor goes bad? The cap I can see, there are wires inside maybe close together with a lot of power going through so that it could fry in time. But the rotor going bad doesn't make sense. It has been said that about 75% of the opti failures are due to the cap and rotor (they always seem to refer to those two pieces together, not one or the other.) Apparently the second most frequent cause of failure is the bearing wearing out so that it seizes or becomes wobbly. Another cause mentioned is the bearing rusting and flaking so that the slots in the disc that spins through the sensor are clogged, or flakes of rust maybe lodge in the sensor. And lastly, the sensor itself goes bad.
Can anyone give a list with the likelihood of each type of failure, or otherwise add a correction or answer to this.

Injuneer

Every time the tip of the rotor passes one of the contacts on the cap, ~30,000 volts jumps the small gap. The tip of the rotor and the cap contacts will "burn" eventually. I've also heard stories of the tip just falling off, the rotor "button" that makes contact with the coil wire contact burning and falling off, the rotor seperating from the piece it screws onto, etc. Supposedly they don't like to rev over 7,000rpm and have been known to disintegrate, but that's not a frequent problem.

You need to add moisture buildup and carbon tracking in the cap as additional problems.

revtime

definately cap and rotor.
I have yet to encounter an optical failure with the optispark but the cap and rotor take a beating just like the old school distributors.
the bearing is next on the list.
Optical portion seems to be fairly robust in my opinion.

GreenDemon

Yes, the wiring inside the cap can go bad. That's what happened to mine, 1 & 7 fired together, which wasn't cool. And yes the rotor can go bad as well, every time the spark jumps the gap in the plug, it also jumps a small gap in the rotor. Every time this happens, a little bit of metal gets burnt away- that's why spark plugs need replaced, and why the cap & rotor need replaced as well.

The optical section is just a big sensor. Solid state components last a lot longer than most mechanical items because nothing ever wears. The only reason they ever really fail is because they get mechanically damaged by other objects or vibration, or they overheat. I am in fact very impressed by how reliable the sensors on my z have been. Let's just say it's pretty unusual for the alternator to outlast the transmission, at least in my book.

If you're looking for a more robust ignition, get the ltcc or delteq. They keep the optical cam sensor (accurate) and use coil packs/coil over plug to fire so there's no moving parts.

blue

Thanks. It's nice to know you know, even if it won't fix the problem. Like if I was horribly sick for 10 years, I would like to at least know what the cause was even if no cure came with it.
I have a question too about moisture doing damage; the ideal situation is for no moisture to get in there at all right? So why did they put DRAIN HOLES in the bottom of the cap (as I remember that's where they are, I don't think they're in the back piece)? Did they put the holes there because it is just impossible to keep moisture out, the idea being, might as well give it a way to get out once it's in? It seems to me the drain holes are just an invitation for the thing to take a soaking, which may be what's happened to mine this time around since it started acting up after a drive through the rain.