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Rapid studdering 3rd gear through to 6th

Jaymac

New Member
Messages
3
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0
Location
Belfast, UK
#1
Hey all first post here,

Recently purchased a 2016 mk7 st-3 fiesta running puma speed stage 2, I noticed a problem when you put foot to the floor in 4th 5th and 6th the car shudders and misfires in quite a rapid succession.

Immediately I assumed spark plugs so got them changed but problem still persists no engine management light is present the blow out valve changes its tone to a slightly more high pitched noise when it shudders but I'd assume that's normal in higher gears.

I can still floor it to a certain point but there's a point where it will struggle to keep pushing.

All help appreciated

Note not sure if coil pack or wiring triggers engine management as they are the individual coils.
 


TyphoonFiST

9000 Post Club
Premium Account
Messages
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7,986
Location
Rich-fizzield
#2
How many miles/KM on the FiST? Stock Turbo? If yes return it back to the stock tune to see if it still persists. It might be the tune. I know your FiST is MAF based Vs. Map tuned also.
 


Lays

Member
Messages
403
Likes
352
Location
Salem, OR, USA
#7
Don't floor it in 4th below 3000 RPM, and don't floor it in 5th or 6th unless you're doing a pull from a lower gear first, low RPM + high gear is terrible for these engines. Easy way to blow them up. (Low speed pre ignition)

I'd check coil packs and injectors next, and maybe tighten your plug gap.
 


TyphoonFiST

9000 Post Club
Premium Account
Messages
11,496
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7,986
Location
Rich-fizzield
#9
I cant say this enough...Ign. Coils break down over time/usage. Should be replaced every 50-75k as a maintenance item. just like O2 sensors every 75k.
 




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