[924CarreraGTP]

Or...... Replace your plug wires altogether if one has recently given you problems. Start fresh. Restore the ignition system. Use OEM german parts. I prefer Denso Iridium plugs but thats my opinion. Bosch plus 2 and plus 4s are cool. When you find one problem in that system, you might as well check the rest of it. One of my plug wires used to blow off until I realized the plug was loose.
I'm going through some problems with my '83 heating up too. I keep the A/C on because it doesn't work and I disconnected the belt for more HP anyway. This keeps the electric fan on all the time and keeps my engine cooler. It could be any number of things. Air flow, fan, thermostat, clogged radiator, or the sensors. If you wanna throw used parts at it, let me know and I can help you for a decent price as can some of the rest of us.