Funky idle
#1
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
well, i go to get in my car to go on my lunch break at work just now, and as i back up out of my parking spot, the idle drops from the usual 850 - 900 to around 400 - 500. i rev it a few times to about 1500 - 2000, then let off, and it does the same thing.
so i start off down the road, and it drives fine, no surging/sputtering, nothing.....until i get to the stop light and let off the gas and go into neutral, then it drops to 400 - 500 again, and is idling kinda rough.
I get to the drive-thru and now it drops to ~500, then after a few seconds, starts to climb back up, around 700 - 750, and keeps doing the same thing the rest of the way back to my job every time i come to a stop and go into neutral.
the car/engine have less than 33k miles on them. it has done this once before, but that time i turned the car off & back on, and it ran fine again.
what would cause something like that? bad gas or a dirty air filter? anything else come to mind?
so i start off down the road, and it drives fine, no surging/sputtering, nothing.....until i get to the stop light and let off the gas and go into neutral, then it drops to 400 - 500 again, and is idling kinda rough.
I get to the drive-thru and now it drops to ~500, then after a few seconds, starts to climb back up, around 700 - 750, and keeps doing the same thing the rest of the way back to my job every time i come to a stop and go into neutral.
the car/engine have less than 33k miles on them. it has done this once before, but that time i turned the car off & back on, and it ran fine again.
what would cause something like that? bad gas or a dirty air filter? anything else come to mind?
#2
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Mine started surging and acting goofy when the O2's started going bad. But with that low of mileage, they should have a lot of life left in them. Has your check engine or SES light come on at all??
#3
TECH Addict
iTrader: (3)
Join Date: Apr 2005
Location: Northern Kentucky
Posts: 2,905
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Possible vaccum leak, when my PCV system lines broke my idle was surging and would dip down really low to like 400-500 range when coming to a stop. deleted the PCV and no more surging or any problems like it again, but if you have the SES light i would check 02s those can mess your idle up or possibly see about the idle adjustment screw on the throttle body.
#4
12 Second Club
iTrader: (11)
Join Date: Aug 2005
Location: Islip Terrace, NY
Posts: 307
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
plugs/wires? maybe ur car is due for a tune up.. and go to an auto parts store and buy techron.. no other crap fuel injector cleaner or anything make sure its techron, wait until ur about 1/4 tank then puta bottle in.. if your not throwing any codes i bet it will work
#5
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
nope, no codes
i doubt it's the adjustment screw on the TB, if the idle comes back up after the car has been running for a while.
but yeah, i'll try some of that techron next time i fill up...i kinda think it might be some bad gas tho, because i just filled up on the way into work tonight, and i stopped at one of the run-down 'hood gas stations, just because i wasn't paying attention to my gas gauge until the "check gauges" light came on, and didn't really have time to double back to one of the places i usually get gas.
Originally Posted by Z28LS1camaroguy
Possible vaccum leak, when my PCV system lines broke my idle was surging and would dip down really low to like 400-500 range when coming to a stop. deleted the PCV and no more surging or any problems like it again, but if you have the SES light i would check 02s those can mess your idle up or possibly see about the idle adjustment screw on the throttle body.
but yeah, i'll try some of that techron next time i fill up...i kinda think it might be some bad gas tho, because i just filled up on the way into work tonight, and i stopped at one of the run-down 'hood gas stations, just because i wasn't paying attention to my gas gauge until the "check gauges" light came on, and didn't really have time to double back to one of the places i usually get gas.
#7
12 Second Club
Join Date: Jan 2008
Location: Carthage,TX
Posts: 112
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Clean the MAF sensor and the Idle Air Control sensor sometimes they might be a little dirty and that caused mine to do what your did. I just pulled off both and cleaned them with B12 chemtool. Make sure not to touch the wires in the MAF youll **** it up and that if you didnt know is expensive to replace. Make sure all the carbon buildup is off the IAC sensor . After cleaning it once all hooked back up leave the iac sensor un hooked and turn key on then hook it back up , turn key off and on a few times then crank and see if that works it did for mine.