5.0L V8 Technical DiscussionsAny questions about the 'Coyote' engine, transmission, exhaust, tuners/CAI, or gearing can be asked here!
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I apologize for the long post but want to provide as much info as I can in hopes of someone being able to help me out. I have a 6 sp 11' GT. I've had the JLT CAI and Bama tunes for at least 5 months now. I originally ran 87 tunes and then decided I wanted to get all the power I could, so I requested 93 tunes. At the same time, I had a Flowmaster cat-back installed. Ever since the new tunes and exhaust were added, I get a hesitation/jerking when accelerating (not even WOT). It is worse at cold starts and gradually improves as I drive. Working with Bama I've tried the idle relearn process twice, battery disconnected for 10 mins with high beam switch on, batt disconnected for 4 hours, switched stations where I purchase gas, removed and reinstalled the intake, and tried using 91 tunes. All this has managed to do is move the range I feel the hesitation from 2K-3K to now about 2500-4000. I'm really out of ideas and am willing to try almost anything short of an exorcism or voo doo witch doctor. Anyone?
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I don't think so but it is possible and the symptoms are in line with what I went through.
Car was running fine, changed the battery out and it started running poorly, surging, stalling and rough idle. Tried the relearning process several times, no go. Cleaned the throttle body and changed the fuel filter as recommended here at MF, it's running like a champ now.
Might be worth it to at least check the throttle body, I know mine was easy to remove, not sure about the 5.0.
I have the same issue in my '12. It first started when i put my axle back, CAI, and Bama tune on. I run a 93 tune all the time, never put 87 in it. Mine only does it with a cold start up though, once it gets up to temp it runs/idles fine. I would like to know why it does that though. If you find out anything else let me know. I may try some of the suggestions listed above.
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2012 Mustang GT Premium
JLT CAI, Kooks Long Tube Headers, Kooks x-pipe, SLP Loudmouth axle-back, Bama 93 Race Tune
Mine has 4K miles on it and it does it when cold, but only for the first min, sometimes I start in 2nd for the first couple of min to minimize the jerking, I really didn't think much of it until I saw your post.
Custom ordered 2012 Mustang GT Premium, Kona Blue, 3.73 rear, Over the Top Stripe and Optional 18" Polished Wheels. Built on Jan 4th, 2012. Added: 2013GT Splash Guards, Ford GT Strut Tower Brace, MGW Shifter, Raxiom Smoked Aero Tail Lights,Moroso Air/Oil Separator
To the OP....try going back to the stock tune, run '93 for a tank+ and see how it is. If it is still there, than it is a stock car issue, if it is gone, it is a aftermarket tune issue. Then deal with the proper business to fix said issues.
Panama City, Fl.
I wake up in the morning with nothing to do and by supper time, I have half of it done.
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