Hey guys I've had a slight random idle miss since the car was new. I've tried front widebands, misfire monitor neutral position relearn, plugs, coilpacks. The is car fine everywhere but idle. it passed a compression test with flying colors, went a 11.93 when it was stock with tire and shocks, and just made 433rwhp with full exhaust intake and tune. It wasn't bothering when I had stock exhaust , but now thAt the bump at idle is more pronounced it's annoying as shit even though it runs like a top. Any help is much appreciated
weird idle miss
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Whats the idle set too on the tune, try bumping it up 50/100 rpms and see how it acts.
it doesn't have anything to do with it, because it had the problem when it was stock
While not the same car I had a srt4 that did the same shit on stock tune and after market tune. The idles were set the same in both so I bumped it up a hair and it helped.....just a thought. Do you have a video of it, mine will do it sometimes when cold but never really payed attention if it does it after its warmed up.
I'm not happy with the idle of mine either. Idled crappy since day one. Now has 2400 miles. If you do a google search you'll see how many people asked the same question over the last few years since the 5.0 came out in 2011. A lot of people said to do an idle relearn. Some say it helped. I didn't try it. I have the type of luck that if I have a 50/50 chance with something, it won't work on mine lol! Do a search for the idle relearn. I forget the exact procedure but I believe it said to disconnect the battery. Wait a while. Hook it back up and start the car and let it idle with everything off, radio, all heat/ac controls for a few minutes. Then take car for a decent drive, 10 or so miles. Again this info might not be 100% correct so do a quick search for exact procedure. It's been gone over quite a bit. You're not alone with the idle problem!
Crap now I remember. My issue was I had one injector acting up. The car ran amazing wot and no other issues but had some random misfires at idle only. And they were brand new injectors too.
No check engine light pointing to the bad injector? Or even a cylinder misfire code??
I was thinking mine had a drippy injector, and if so, hopefully it gets worse and trips the check engine light, then I will know atleast what cylinder to go after.
Started as just a random misfire, then finally tripped a check engine, moved the injector and the code followed so replaced that one injector......of coarse this was after new plugs, wires, coil blah blah blah rofl.
it might but it would just be hiding the real issue
no codes and it moves from cyl to cyl I can watch it on my IDS when I do a power balance. I did the idle relearn also
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Haha, of course!
Hey, if you come up with anything, or find a fix, please let the rest of us know! I wouldn't mind a bad idle if this was strictly a drag car and had tons of modifications done to it, but it's not a drag car and is bone stock so far..
I'm sure Ford will come out with a pcm re flash eventually, if they haven't already, or maybe even one of the aftermarket tuners could somehow see what the idle is doing at idle and adjust a few things or whatever. I'm sure there is a fix out there somewhere. The way I feel is a 2014 car should not idle like this. Yes, I know we bought Mustangs, and not a luxury car that idles so smooth you can put a glass of water on the dash and it won't shake! I just feel with all the technology we have in this day and age, these cars should not idle like they are missing and not running right..
don't know what to tell you man, I've seen/heard so many people talk about this
I think if it was actually missing, the check engine light would be on with a misfire code..
These cars do normally 'miss' at idle due to the idle strategy Ford uses.
There is no idle air valve, it's all throttle control and when you are talking about an 80MM Throttle body, very small adjustments can cause LARGE swings in idle RPM. Ford uses the throttle angle secondary to Ignition timing when controlling idle.
Data log your idle and when you hear the 'miss' you will see spark drop down very low (sometimes negative).
There is no idle air valve, it's all throttle control and when you are talking about an 80MM Throttle body, very small adjustments can cause LARGE swings in idle RPM. Ford uses the throttle angle secondary to Ignition timing when controlling idle.
Data log your idle and when you hear the 'miss' you will see spark drop down very low (sometimes negative).
Chevy does the same thing with timing at idle I am familiar with it. It's just odd that mine has a loud bump when the local ones I've seen don't including my last one. This idle strategy is definitely why they all have a rough idle though.
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