Low idle rpms

[RayRay]

So I've been researching this topic thoroughly lately and I would like some input. Will it really "hurt" my car to idle 100 or so toms higher? If it's shuddering when idling low is there a possible problem? If so what? Let me know what you know.

[navylife59]

Is your MIL (CEL) lit? It is possible that you have a vacuum leak. On carbureted engines, this would speed up the idle speed some as the A/FR's are usually rich. On fuel injected engines, it can cause the opposite effect. The idle will lower or even oscillate as the ECM (ECU) tries to compensate with the IAC (Idle Air Control) to maintain proper A/FR. There are many other factors like dirty MAF sensors, clogged/contaminated O2 sensors, clogged catalytic converters, dirty injectors, bad gas, etc). Do you experience any other engine running abnormalities? When did this start happening?