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Discussion Starter #1
I haven't run the 'stang for about 10 or 11 days because of snow but the roads are nice and clear so I took it to work today. Was just sitting in it with it idling in neutral, engine warm, while stuck waiting for a train and I noticed it was idling back and forth between about 600 and 750 rpms which doesn't seem terribly out of the ordinary but then it would drop to about 500 and nearly shutoff, catch itself and ramp back up to 750, go back to close to 500 again and then eventually just do the 600 to 750 thing again. It'll then run smooth for a while with little to no fluctuation;however, when I got back to work I let it idle for a minute and it repeated the whole process. Any ideas? It runs fine otherwise. The weather has been in the teens at night the past few days so I'm thinking maybe the gas in the tank isn't any good anymore but perhaps one of you has a better idea of the issue.
 

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We're you running your defrost? When running the defrost the A/C COMPRESSOR kicks on to evaporate the moister in the air so it doesn't fog up the windows!!
 

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R u tuned and intake... My intake clamp came loose one day and that happen to me... Clamp to the throtle
 

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No, heat was on low blowing on the floor.
If you parked with less than full tank there is possibility that you have moisture in gas tank. When this happened to me before I used the Heet water remover and it works but there are lots of choices out there. Any parts store should know what's good for your car.

Hope this helps.
 

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I had a bad tune that did this myself. Everytime the engine fan came on, my car would almost stall. I had to get new tunes anyway and it stopped.

I know it was the tune because I took it back to stock, it didn't do it, then went to the tune and started doing it again.

Never done it since.
 

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Discussion Starter #8
Car is bone stock minus axle back. I'll look into water remover, that's a good possibility.
 

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Car is bone stock minus axle back. I'll look into water remover, that's a good possibility.
Was there any time where the battery died or was disconnected?

You may try to cycle through the complete idle relearn process (in the manual) to help the erratic idle behavior.
 

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Discussion Starter #10
Was there any time where the battery died or was disconnected?

You may try to cycle through the complete idle relearn process (in the manual) to help the erratic idle behavior.
It didn't but that'll also be something I could try anyway.
 

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Discussion Starter #11
Put water remover in and filled the tank. Twenty minutes into the drive it shut off while coasting with the clutch in for maybe 3 seconds. Got home and it idled fine for a few minutes, then started idling like crap and then back to normal. I took a video of it idling badly and then at the end it goes back to normal. Don't know if you can hear it or not but you can see the needle.

https://www.youtube.com/watch?v=htxpVPfJsF8&feature=youtube_gdata_player
 

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Put water remover in and filled the tank. Twenty minutes into the drive it shut off while coasting with the clutch in for maybe 3 seconds. Got home and it idled fine for a few minutes, then started idling like crap and then back to normal. I took a video of it idling badly and then at the end it goes back to normal. Don't know if you can hear it or not but you can see the needle.

https://www.youtube.com/watch?v=htxpVPfJsF8&feature=youtube_gdata_player
So from a cold start, start with AC off... Let it sit without touching accelerator until warm (10 min or so)... Then let it sit for 10 more with ac on. Also without touching accelerator. See if that helps the system figure out what it is doing...
 

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My car has a Steeda tune and intake, and sometimes my idle is a little inconsistent. other days, rock solid. I checked intake connections and cleaned the MAF ... seemed to help a little ... never stalls or comes close but it's noticeable on some days.

---------- Post added at 06:23 PM ---------- Previous post was at 06:23 PM ----------

So from a cold start, start with AC off... Let it sit without touching accelerator until warm (10 min or so)... Then let it sit for 10 more with ac on. Also without touching accelerator. See if that helps the system figure out what it is doing...
I thought the relearn was like 2 minutes of each?
 

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My car has a Steeda tune and intake, and sometimes my idle is a little inconsistent. other days, rock solid. I checked intake connections and cleaned the MAF ... seemed to help a little ... never stalls or comes close but it's noticeable on some days.

---------- Post added at 06:23 PM ---------- Previous post was at 06:23 PM ----------



I thought the relearn was like 2 minutes of each?
10 minute from cold start...

Mine seemed to do better the longer I let it idle after my tune.
 

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Discussion Starter #16
.....the cap on the intake from the sound tube delete fell out. I'm sorry everyone haha.
 

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.....the cap on the intake from the sound tube delete fell out. I'm sorry everyone haha.
No apologies needed!! Glad it was no big deal!!!
 

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Discussion Starter #18
It was interesting though. I started the relearn process and when you start it it's literally like the thing forgot how to start and run and then slowly smooths out.
 

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Lol. Glad to hear you solved the issue. I do check that cap too periodically, what I used is the chair rubber footing that I bought at Ace Hardware, perfect fit though so it hardly worries me at all.
 

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Discussion Starter #20
Lol. Glad to hear you solved the issue. I do check that cap too periodically, what I used is the chair rubber footing that I bought at Ace Hardware, perfect fit though so it hardly worries me at all.
Yea I used that and it felt snug but I must have trimmed it a little too much :(
 
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