94 LT1 Opti spark. What should the rotor look like?

I have a 94 Z28 with an opti spark distributor. I had it replaced about 6 months ago along with the coil, ecm, wires, and plugs. Recently, it started missing at low rpms. I changed the plugs and
wires (2ond time) and it still misses.
I now have the distributor off and the rotor looks terrible. No contamination, but it doesn't look like it is not making contact with the electrodes in the dist cap. Spark by osmosis??
In all my experience with traditional ignition systems the rotor always contacts the electrodes, if not, replace the cap and rotor.
Is the optispark any different? Should it be this way?
I would think if it is not making contact, it wouldn't run at all.
Steve...
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The rotor NEVER should contact the "electrodes" on the cap. there is supposed to be a small air gap between the contacts on the cap and the rotor the spark jumps this gap the same way it jumps the gap on a spark plug. check the rotor for signs of wear (wears like a plug too) but chances are it needs em replaced. The optispark unit is recommended to be changed as an assembly, but the cap and rotor is available separately. Brian
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This is a multi-part message in MIME format. --------------010605090804010604040403 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit
Check your water pump for leaks! This is a common problem. Coolant gets into the dist.
Steve wrote:

--------------010605090804010604040403 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta http-equiv="Content-Type" content="text/html;charset=ISO-8859-1"> <title></title> </head> <body text="#000000" bgcolor="#cccccc"> Check your water pump for leaks! This is a common problem. Coolant gets into the dist.<br> <br> Steve wrote:<br> <blockquote type="cite" cite=" snipped-for-privacy@posting.google.com"> <pre wrap="">I have a 94 Z28 with an opti spark distributor. I had it replaced about 6 months ago along with the coil, ecm, wires, and plugs. Recently, it started missing at low rpms. I changed the plugs and wires (2ond time) and it still misses.
I now have the distributor off and the rotor looks terrible. No contamination, but it doesn't look like it is not making contact with the electrodes in the dist cap. Spark by osmosis??
In all my experience with traditional ignition systems the rotor always contacts the electrodes, if not, replace the cap and rotor.
Is the optispark any different? Should it be this way?
I would think if it is not making contact, it wouldn't run at all.
Steve... </pre> </blockquote> </body> </html>
--------------010605090804010604040403--
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In any rotating ignition system:
The rotor never contacts the pole on the distributor cap. In fact, there is a way of measuring what's called: "The Rotor Gap" on the oscilloscope, to see if all are equal.
My guess is that, the dexcool entered the distributor, and contaminated the pickup coil or photo cell. Which ever they are using.
You can clean the inside with electronics cleaner. The rotor can be electrolosysed by the Dexcool, and made to not conduct the spark across the rotor gap as well.
So I would spray out the distributor with electronics cleaner spray, CRC Brand is what I recommend. Then replace the rotor. Before you do anything, inspect everything closely; for an orange/brownish residue. if there is any trace of these colors. The water pump is definitely to blame for the untimely corrosion of the rotor.
Refinish King

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Very good and accurate post from RK.
GM has had numerous problems with the water pump leaking on all these LT1 (5.7 vin P) vehicles. Joe--ASE Certified Parts Specialist & 10th Ann.Club Tech Director '80 Carousel Red Turbo T/A, 26k orig. '79 "Y89" 400/4 speed 10th Ann. T/A, 57k orig '84 Olds 88 Royale Bgm 2 dr, 307 "Rocket" (lol), 141k and still going.... '80 T/A project car...
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snipped-for-privacy@aol.com (Bigjfig) wrote in message

Follow up...
There is no visible contamination. I looks as if moisture got in through the vent holes this winter. Hot engine...cold damp garage. The water pump is not leaking, it was just replaced. Nothing was wet in any way. Just some corrosion on the rotor. The optical disk was bright and shiny. I cleaned up the rotor and sealed the assembly. No change in performance, it still misses at low rpms no/low load.
My mechanic suggested a power flush of the fuel injectors. It seems to make sense, it's not a teeth jarring miss, more of a fart. I'm thinking that the injector spray is crappy. I'll give that a try and let you know.
Steve....
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I would consider the moisture left a residual haze on the optical pickup.
I would still spray the optical pickup and the photocell, and also. Never seal the vent holes!
This can lead to ionization inside the distributor cap, which at the very least can cause a misfire and breaking up at higher RPM's, or at worse case. Blow the distributor cap right off.
Every time there is a spark, there is metal consumption between the rotor and the cap pole piece, which causes ionization of the ambient air in the distributor, especially at the intense voltages the Optispark works at.
Reconsider plugging the vents please?
Refinish King

gets
with
LT1 (5.7

going....
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