low idle?
10-20-2007, 01:48 AM
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low idle? i was driving home tonight and my car, when i was comming to a stop, would idle anywhere from 400 rpm to 600. does anyone know why this is? please help. thanks.
10-20-2007, 01:58 AM
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Sounds like your iac(idle air control) isnt working correctly. Its the top sensor on the throttle body. If it keeps happening try resetting it, with the car off unplug it, then turn ignition on(dont start) for 10 sec. Then turn off, plug in the iac sensor, turn ignition on again(dont start) for 10 sec. Then turn off. Go around driving and let the iac relearn its self.
If this doesnt work then the sensor could be bad or you might have another problem like ignition missfire of something. How does the car drive? like normal? Tim
If this doesnt work then the sensor could be bad or you might have another problem like ignition missfire of something. How does the car drive? like normal? Tim
10-20-2007, 02:47 AM
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honestly I never noticed the problem until after I swapped a ported TB onto my car.... however, I've read that occasionally the holes in an epoxied TB can lead to an erratic idle because they're a bit small... any idea if that could be true Tim? and if so, what size normally is the holes in your epoxied TB?
for what it's worth... mine only does this when it's humid outside, when it's cool and far less humid, I never have the problem (so, needless to say, it happens more during the day than during the night) ... being in Houston, simply sucks for that... also it happens far less if my AC is off, but again, being in Houston, it's a rare occasion that it's off (so my idle does dip a lot)
as for the sensor being bad, seems a fairly rare problem, and if it does indeed go out, its about $140 to replace...
resetting the sensor once helped with other problems but I still had the idle problem, so I'm thinking next time I try to reset the computer, maybe leave the AC off entirely, or leave it on, and not mess with anything else.
late night ramblings suck.
for what it's worth... mine only does this when it's humid outside, when it's cool and far less humid, I never have the problem (so, needless to say, it happens more during the day than during the night) ... being in Houston, simply sucks for that... also it happens far less if my AC is off, but again, being in Houston, it's a rare occasion that it's off (so my idle does dip a lot)
as for the sensor being bad, seems a fairly rare problem, and if it does indeed go out, its about $140 to replace...
resetting the sensor once helped with other problems but I still had the idle problem, so I'm thinking next time I try to reset the computer, maybe leave the AC off entirely, or leave it on, and not mess with anything else.
late night ramblings suck.
10-20-2007, 08:27 AM
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Well i drill my iac holes out to 3/8", this is alot bigger than anyone else does. Most people always used to say that 1/4" was enough but jimmyblue just did some testing and 1/4" holes limited the max airflow to about 11 g/sec, and a 3/16" hole had stock airflow. So i drill mine out twice the 3/16" to 3/8" and it gets all the air it needs. If your having a low idle problem turn the idle screw up some. Start by half turns and see how it helps. Might be just enough to help idle smooth its self out so the iac doesnt have to let by a ton of air. Tim
