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

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

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

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...

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....

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