Ignition Distributor Cap And Rotor

[www.kevingerard.net]

We have a 1992 Lexus SC300. It Sometime gets a minor misfire at Idle.

We removed the Distributor cap and found the rotor was cracked and spark was jumping through the crack and burned a hole in the rotor.

We installed a new cap and rotor and 1 week later another misfire at idle. We removed the cap and found the rotor cracked again.

I checked the Distributor shaft and bearings for side slack, and also up and down slack, but there was none. It is tite. Making sure the cap and rotor are in place perfectly! (experienced tech I am) we installed our now 3rd rotor.

One week later it again started sometimes misfiring at idle. I removed the cap and found our 4th rotor in 30 days cracked and spark juming though the crack causing misfire at idle.

We have used 2 differnt kinds of rotors.

My next step is to try a factory Cap and Rotor from Lexus.

Anyone ever have a simular problem?

Also all of this started after Lexus replaced the Distrbutor 'o'ring seal (free warranty work) but never had the problem before that, only after Lexus did this work. We have also moved at the sametime and the dealer is no-longer close by.

Thanks, Kevin

[SKperformance]

I would say the shaft where the o ring was installed is misaligned causing it to crack under high rpm speed wobble.