Well tomorrow I try to pass DC emissions again and I changed my spark plugs this morning. The back set of plugs were fouled pretty badly whereas the front ones had the normal wear after about three years. I'm terrified of this question but do fouled plugs indicate a bigger problem? My '86 GXL runs fine, idles great and all the ports work. Why would just the rear plugs (rotor closer to the flywheel) foul out? My daughter lost the digital camera at an amusement park but I'll try to post pics of these plugs soon.

 

well possibly your apex seals are starting go, or you have a low compression ratio and it could be causing detonation.

 

Sadly it could only be they are not burning such as dead plugs or wires. Or the rear rotor is gone. You would have to do a compresion test to know this.

Another way is the car will run on one rotor. Actualy will run on one rotor with one spark plug lol. Start it and pull the plug wires from the 2nd rotor if it dies and you have spark you know its dead.