hey guys

i have a pinging problem with my 1989 300E (3.0L). whenever you full throttle (full load) the vehicle in hot weather, the car starts pinging. it does not do this in cold weather. (i assume due to richness).

anyways, i replaced everything on the vehicle (air flow sensor, fuel distributor, ignition coil, ezl ignition box, rr crank sensor, throttle body and sensor, air filter, spark plugs, spark plug wires, and fuel filter), and i only use super unleaded gas. i even used sea foam carbon cleaner in my intake, gas tank, and engine crankcase. all this treatment seemed to help dramatically, but it still seems to ping a little in hot weather and full load.

this did not cure it 100%. i already bought an ezl resistor from a mbz dealer. i opened it up and saw no resistor but an actual diode. what's this all about?i went from a resistor type to a diode type.

should i change it to a resistor type and change the value? would this solve my pinging problem under full load? if so, should i use the values you describe for my retard?

let me know.

andy