Definition of quantal. 1  1 [Latin quanti how many, plural of quantus] : of, relating to, or having only two experimental alternatives (such as dead or alive, all or none) 2  2 [quantum] : of or relating to a quantum.
3. Engine movement. Another symptom of bad or failing engine mounts is an engine that moves in the engine bay. If the engine mounts are in good condition, they should be able to secure the engine firmly in the engine bay.
The Nature of the Problem. Many things can cause an engine to lose power: bad timing, airflow obstructions going into or out of the engine, carbon buildup on spark plugs, bad gasoline and improper fuel burn in the cylinders are just a few. But these things don't often cause engine hesitation -- at least, not initially.