How to tell when its time for a new Distributor Cap ?
 

How to tell when its time for a new Distributor Cap ?

Just wondering on this. I usually check the terminals on the inside and the rotor, but again, how do you know when they are done ?

you can look at them and see there is a lot of build up on them, but that doesn't always tell the tale, you can look for burn marks and cracks but often unless you use an occiliscope to monitor parade pattern and firing voltages, you won't be able to see always where secondary ignition faults are:)

I usualy change mine when ever I change the plugs and wires. Stock cap and rotors are usualy around $20.