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View Full Version : any lt1 owners have/ had this prob?

sjersey93z28
02-19-2012, 03:18 PM
Car at stop light rpms surge from 1000 to 1200 up and down than shoot up strong to about 2000 than smooths out and idles fine? Or sometimes stalls out but that's rare. Car jus had new opti, new tune, new o2's.
sweetbmxrider
02-19-2012, 08:08 PM
If you could read datastream, you should look at your IAC (idle air control motor) counts. You may want to take it off and clean it with carb cleaner along with the throttle body and passages. Carbon will ef with it. Just realizing now you said new tune. Do you mean someone tuned the PCM? That could obviously cause some issues if they didn't do it correctly.
LTb1ow
02-19-2012, 08:09 PM
What brand opti and 02s?
sjersey93z28
02-19-2012, 09:38 PM
Not sure brand of opti but car was doin this before the tune, the opti, or the o2s.were changed.
Lt1_8U
02-19-2012, 10:07 PM
If you could read datastream, you should look at your IAC (idle air control motor) counts. You may want to take it off and clean it with carb cleaner along with the throttle body and passages. Carbon will ef with it. Just realizing now you said new tune. Do you mean someone tuned the PCM? That could obviously cause some issues if they didn't do it correctly.

i agree, i had a similar problem and it ended up being the IAC. also could this be happening due to a vacuum leak?
sjersey93z28
02-20-2012, 09:35 AM
Im gona try cleaning it and see what happens and I'm gona clean the MAF while I'm at it. I apreciate the ideas.
WildBillyT
02-20-2012, 09:37 AM
Im gona try cleaning it and see what happens and I'm gona clean the MAF while I'm at it. I apreciate the ideas.


Good idea. As mentioned above, inspect your vacuum lines too. If they are still the original ones they could be cracked.
sjersey93z28
02-20-2012, 09:43 AM
Yea ill check them when I dig in and start cleaning everything. Also gona header wrap my headers to keep heat in the exhaust to try and see if the o2s will get more acurate readings.
WildBillyT
02-20-2012, 09:45 AM
Yea ill check them when I dig in and start cleaning everything. Also gona header wrap my headers to keep heat in the exhaust to try and see if the o2s will get more acurate readings.

If you mean wrap the tubes with the heat wrap, don't bother. Will shorten the life of your headers and won't help the O2s at all.
sjersey93z28
02-20-2012, 09:51 AM
Ok was a thought. I'll start with the basics see wat happens.