Hey guys, did some code counting today and counted a code 8, Top Dead Centre sensor as well as a code 65. I was curious what this TCD sensor was all about? I searched on here and couldn't find much. Any info is much appreciated. Thanks guys.

 

This sensor, along with the CYL and CKP sensors, are located inside the distributor. They are used to coordinate fueling and timing events. The sensor has a resistance spec that you can compare to the Helms spec (around 350 ohms). If the resistance test is alright, then you need to check the wiring associated with this sensor, making sure that it isn't open or shorted to ground.

Code 65 is for the 2nd O2 heater. Helms specs this at 15-40 ohms. Again, you need a meter to measure. If resistance checks out, check the wiring.

I'd suggest buying a Helms manual for your car, as well as a multi-meter.