civic 93 engine self reving need help

**darkbloodlestat** · May 26th, 2012 02:04 PM

posting for a friend mga gurus:

my friend's car is a 93 civic all of a sudden 2 days ago we noticed after a cold start the engine was reving on its own in constant interval, ganun parin sya hanggang ngaun kahit restart at mainit n makina

anu kaya problem nun mga gurus? anybody encountered that before? and how do we solve that? thanks

**darkbloodlestat** · May 27th, 2012 08:13 AM

any input guys??

**jick.cejoco** · May 28th, 2012 05:44 AM

your car is equipped with the traditional throttle cable. try cleaning the throttle body and the idle air control with carburetor cleaner. the gum and varnish from the fuel and the oil evaporation from the crankcase attracts dust that compounds the gumminess at the throttle plate. to reduce the recurrence, use good quality engine oil and check the cooling system thermostat to make sure it is not stuck open

**darkbloodlestat** · May 28th, 2012 05:47 AM

thank u sir

done cleaning the throttle body, auto reving has stopped but still at high rev, IACV adjusted to the limit yet still at 2K rpm at idle and does not go down as it should, any more ideas?

**jick.cejoco** · May 28th, 2012 06:24 AM

check engine vacuum. if the engine is ingesting false air (air entering the intake that did not pass thru air flow metering), the idle will be high. if you still have an ignition distributor, check base ignition timing and check if the idle speed stop had been tampered with (usually sealed with some white paint). also, check the pcv valve to make sure it is not stuck open. the gum that went to the throttle has more than likely affected the pcv valve making it slow to respond and modulate crankcase gas flow