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.
A bad crank position sensor can worsen the way the engine idles, the pistons fire, or the acceleration behavior. If the engine is revved up with a bad or faulty sensor, it may cause misfiring, motor vibration or backfires. Accelerating might be hesitant, and abnormal shaking during engine idle might occur.