Sounds like your timing is way retarded. I think you are treating the symptom and not the disease. If your car is indeed "pinging", then you need to look at your knock sensor and also your distrubutor to see why the timing is so far off.
The only other thing I can think of is heavy carbonization in the cylinders themselves. Heavy carbon raises compression and hence the hot glowing carbon as well as the higher compression will cause a bad ping.
If the knock sensor checks out okay, I think if I were you I'd swap in a rebuilt distributor because the knock sensor only prevents pinging, it doesn't cause it.
Some data on the ESC system:
The Electronic Spark Control (ESC) system is comprised of a knock
sensor, the ESC module, and the ECM. As the knock sensor detects engine
knock, it sends a voltage signal to the ECM. The ECM responds by
retarding the ignition timing until the knocking ceases. As detonation
is reduced, the ECM advances the timing again in small increments back
to the pre-programmed point for that engine speed and load.
Ignition Timing Should Be:
2.8L
10 BTDC
0
0
