steelhitman1245

2000 accord lx 141,xxx miles f23a4 motor, 5 speed manual. i was going to adjust my idle, so i unplugged the iacv like i read your supposed to and the idle started loping. it was jumping from from 1000 to 1200 rpm. so i was always told that the rpms should either drop or rise depending on where the idle control screw was adjusted to and it did neither, it just started loping. it doesn't happen when the iacv is plugged in btw. what could possibly cause this?

jdmcertified909

vacum leak

steelhitman1245

i hate to sound doubtful but if it was a vacuum leak wouldnt that cause the loping idle all the time?

holmesnmanny

When you adjust the idle you need to pull the radio fuse or the negative cable for 30 seconds or so so the ecu can relearn the idle. Assuming you don't have a vacuum leak, the ecu needs to relearn the idle. But, before you restart the car after plugging the iacv back in you need to let it completely cool. Then start it up(in the morning or so) and let it idle until operating temp.

newhondafan1

This may be a little off topic..but does a loping idle 3500-800 at start up indicate a vacuum problem?

holmesnmanny

No, you probably just need to tighten the FITV down. Look in the FAQ's at the top of this forum for how to clean your IACV and FITV.