... Ping, pre-detonation or pre-ignition, (the mixture firing before the spark of the plug) can be caused by a very wide variety of things or a combination of them. engine timing might be wrong or a worn timing chain but carbon build up is a leading cause.

Below was written for vehcles with carburetors

(1) Compression ratio of the engine can be too high for the octane rating and/or the vaporization temperature of the fuel being used. Carbon deposits can not only ’glow’ and cause pre-ignition but add to the compression ratio of the engine. The act of compression creates much heat in the fuel-air mixture. The volatility and vaporization temperature of gasoline varies from station to station and area to area. There are several methods to remove carbon deposits quickly.

(A) Run a warm engine at 1/3^rd less than the red line RPM and pour half a gallon down the carburetor just fast enough to not kill the engine then drive it like you stole it for ten to fifteen miles.

(B) Run a warm engine at 1/3^rd less than the red line RPM and pour quart of cheap ATF fluid down the carburetor just fast enough to not quite kill the engine. Then when the quart is empty stop the engine and wait a couple of hours then drive it like you stole it for ten to fifteen miles. Be warned, both of these carbon removal techniques will create an ungodly amount of smoke! And might be harmful to a catalytic converter!

What you used may have been "Sea Foam".

UPPER LUBES fight Carbon and Wear

Have a good one   and  CUL.. Don S..