Dieseling in Acceleration

[scent of a mule]

Have a 1997 206k miles. Notice when I accelerate while already underway, there is a 1-2 sec dieseling sound. I put in new plugs, ran some sea foam but no improvement. Any suggestion on diagnosis or repair?

 

[BILT4ME]

That's called ping, pre-detonation. Use a higher octane fuel. Test your knock sensors. Check your base timing. Check your ignition system. Plugs, wires, cap, rotor.

Don't do that for long or you may end up with an aerated piston.