# spratic idle problem



## Donavin (Mar 27, 2004)

about 20% of the time when im slowing down from regular driving (2k-3300 rpm) my engine will idle at a pulsating rate from 1500 to 1800 rpm then slowly curb itself down to the regular 700ish after anywhere from 10 seconds to a minute of idle. and id say about half the time its not doing the pulsing high idle its idling at 1k-1100 rpm for a few seconds before it slows down. no computer code readouts, no excessive fuel consumption, no power lag, nothing else crazy. it is an 89 with 152k miles on it so stuff is starting to wear out. just wondering if anybody has had similar probs and what they did to fix it.

recently replaced the o2 sensor spark plugs and wires, haven't touched maf, tps, or fuel pump yet.


----------



## ProjectH213 (Dec 6, 2004)

i had the same problem with a civic i use to own. it could be a number of stupid things idle to high or to low, air in coolant, or dirty eac valve. i'm not sure if 240's have a eac(electronic air control) valve but what it does is lower your idle after warm up. these are all problems me and my friends had when we were big into hondas. good luck i know this is more a pain in the ass then anything but relax you'll figure it out.


----------



## Joel (Jun 11, 2003)

they do - its called an IAC valve (idle air control) and it open to bypass air past the butterfly to make the engine rev higher when the car is cold. When its stuffed it opens and closes in an infinite loop making the engine 'hunt'


----------



## nismo200sx16 (Aug 25, 2004)

whats "hunt"?


----------



## Joel (Jun 11, 2003)

revs go up and down continuously - like the engine cant decide where it wants to idle


----------

