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Stock 19 EcoPP MT 12k miles. Car seems to stutter in 3rd between 3200-4500 rpms doesn't feel right like it's not getting enough air or fuel...any insight?
What is your AFR gauge reading while your car is stuttering?
 

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That's pretty close to want it should be, which confirms correct air to fuel ratio. Do you have a data logger?
 

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Another option is to have someone record your gauges, especially the AFR gauge as your car stutters and let us know what they saw.
PS; Also record your speed and rpm.
 

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More, as designed, fuel than air! Before you dig into your ECU and fuel/air system, pull your plugs and injectors, check for anything odd. If everything looks good, re-gap your plugs (.028 is where I run mine when burning 93 octane) and reinstall them.
Let us know what you find!
 
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My car stuttered a lot when my spark plugs were in incorrect gap size. Maybe check that as well?
Do you remember what your plugs were gapped at and what gap you reset them to? I've never had an issue with the spark being blown out, but I have heard other forum members mention this issue.
Also, did it cause a code of any type?
 

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Do you remember what your plugs were gapped at and what gap you reset them to? I've never had an issue with the spark being blown out, but I have heard other forum members mention this issue.
Also, did it cause a code of any type?
Surprisingly it did not throw a code. I got the plugs "pre-gapped" from Tune+ and put them in without checking. I took them out and they were all gapped to 0.018, After I gapped them to .028 and everything has been fine since then. I have the NGK 6510 1 step colder plugs.
 

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Surprisingly it did not throw a code. I got the plugs "pre-gapped" from Tune+ and put them in without checking. I took them out and they were all gapped to 0.018, After I gapped them to .028 and everything has been fine since then. I have the NGK 6510 1 step colder plugs.
Interesting... I also got some professionally gapped plugs that were wrong. They were .024+/- and I gapped them to .028 for 93 octane and after I switched to ethanol, I re-gapped them to .026
As far as the spark being blown out on plugs, I'm assuming it is because the gap is too large. But, I'm not sure, I've never had that problem, but in theory, it would leave unburnt fuel in the system, just like some types of misfires.
 

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When I get a chance this weekend, I'll check the plugs and injectors. The rest of the week my life is busy with buying, selling, and fixing guns...
Concerning AFR... Mine is currently running 11.5 on ethanol racing fuel, plus dual injectors and aux. controller. But, when I was running 93 octane with OEM injectors and factory fuel map, my ECU kept my AFR at 14.7
 

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On my stock 2020 hpp the AR always goes to less than 10 at WOT when over 5k rpm. Others have also noticed this. Safer to run a turbo set up rich than lean. I think it is Ford protecting the catalytic converter from getting tooo hot and failing in warranty. It runs 14.7-15 just driving around.
 

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When I get a chance this weekend, I'll check the plugs and injectors. The rest of the week my life is busy with buying, selling, and fixing guns...
What mods does your car have? I agree with the others regarding checking your spark plugs, but if your running the stock tune or a 91 or 93 octane tune, you don't need a colder heat range spark plug. Colder plugs won't make your car run any better and will greatly reduce your plug life. Cobb and Ford Performance don't require colder plugs on their tunes. The only ones that recommend colder plugs are a couple of tuners that sell plugs. The stock Motorcraft plugs work well when gaped to .028".
At idle, when cruising, and up through moderate acceleration your AFR should run close to 14. During heavy acceleration through WOT, your AFR should drop to 10-11. Good luck and keep us posted on what you find.
 
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