tingin ko wala nga epekto sa hatak yung setting ng idling. sa fuel consumption may effect na to pero hindi substantial.. wag lang sobrang taas ng idling say more than 1200 rpm. Normaly 700-900 rpm ang setting ng cars (usually mas mataas ng 100 rpm or same with aircon on) pero when you set the rpm when tuning, wag mo masyado pansinin yung reading kung baga e feel the car kung di ma masyado nagba-vibrate yung engine e ok na yun (tip sakin yan ng mekanik namin), typically less than 900 rpm, pag sobra dun e saka mo babaan.

pag mahina hatak, try using a higher octane gas (simplest), then check the plugs, then check the timing, then the carb (kung carb-type). Pag dati ok hatak ng car then bigla parang makupad, pa check mo timing.. ganyan kasi corolla namin dati, nalihis pala timing nung last tune-up pina advance nag konti at ayun.. back to normal na.

imho lang po.