• Welcome to Mustang7G!

    If you're joining us from Mustang6G, then you may already have an account here!

    As long as you were registered on Mustang6G as of March 10, 2021 or earlier, then you can simply login here with the same username and password!

Misfire Issue help!

TOXIC_S650

Member
Joined
Mar 24, 2024
Threads
4
Messages
7
Reaction score
6
Location
Montana
Vehicle(s)
2024 Mustang GT Premium
So been driving my 2024 GT Premium for over a year and a half, no issues. It had about 3700 miles and I installed a new racing clutch and short throw shifter last month in preparation for my supercharger install coming up later this month. After these two were put in, my car shakes in first gear and my engine light flashes. Took it back to ford and they said its due to a 4 and 7 cylinder misfire. After diagnosing, they said due to the misfires, the engine is putting itself into 4 cylinder mode which will cause shaking. It's definitely running on 4 cylinders because all of my power is gone. Its been a month and a half and they said there is nothing they can do, but the supercharger tune will fix it so not to worry about it. Was never a problem before I installed the new clutch and shifter. Anyone heard of this and have any suggestions? Will the supercharger tune fix it? Thanks.
Sponsored

 

S650sunshine

Well-Known Member
Joined
Dec 26, 2024
Threads
7
Messages
145
Reaction score
67
Location
USA
Vehicle(s)
S650 GT
So been driving my 2024 GT Premium for over a year and a half, no issues. It had about 3700 miles and I installed a new racing clutch and short throw shifter last month in preparation for my supercharger install coming up later this month. After these two were put in, my car shakes in first gear and my engine light flashes. Took it back to ford and they said its due to a 4 and 7 cylinder misfire. After diagnosing, they said due to the misfires, the engine is putting itself into 4 cylinder mode which will cause shaking. It's definitely running on 4 cylinders because all of my power is gone. Its been a month and a half and they said there is nothing they can do, but the supercharger tune will fix it so not to worry about it. Was never a problem before I installed the new clutch and shifter. Anyone heard of this and have any suggestions? Will the supercharger tune fix it? Thanks.
Idk if ford telling the truth with the 4 cylinder mode thing. Did you install the mods yourself? Idk this issue tbh.
 

dusman59

Well-Known Member
Joined
Mar 8, 2023
Threads
10
Messages
642
Reaction score
549
Location
AZ
Vehicle(s)
2011 GT glass top & 2024 GT
Do you need to do a crank shaft relearn? I know this was almost needed on earlier Mustangs when installing a new clutch.
 

MAT1955

Well-Known Member
Joined
Sep 1, 2024
Threads
12
Messages
486
Reaction score
616
Location
K6V4T5
Vehicle(s)
2024 Mustang GT
Start with the fact that you changed the car that was running fine and work out who did what to your Mustang.
 


dusman59

Well-Known Member
Joined
Mar 8, 2023
Threads
10
Messages
642
Reaction score
549
Location
AZ
Vehicle(s)
2011 GT glass top & 2024 GT
You definitely need a relearn. Missfires and limp mode happen when the crank sensor is disturbed.
 

Q6543

Well-Known Member
Joined
Dec 11, 2022
Threads
21
Messages
1,575
Reaction score
1,950
Location
Detroit
Vehicle(s)
1993 fox
First thing I’d do is pull your spark plugs and re gap them down to 25 thou…

super common in the past if it’s happening in higher rpm/boost… spark blowout from bad gapping… causes misfire
 

dusman59

Well-Known Member
Joined
Mar 8, 2023
Threads
10
Messages
642
Reaction score
549
Location
AZ
Vehicle(s)
2011 GT glass top & 2024 GT
You might be right if he had force induction installed. He installed a new clutch. Wipple coming soon.
 

roket

Well-Known Member
Joined
Sep 22, 2022
Threads
69
Messages
2,165
Reaction score
3,192
Location
Cave Creek, Arizona
Website
roketgamer.dev
Vehicle(s)
2024 Ford Mustang Dark Horse
my dealer just had a supercharged 2024 come in with a misfire on one cylinder, turns out the spark plug on that cylinder was absolutely gapped too much. check your spark plugs, especially the problematic ones, and ensure the gap is appropriate. i also misread your original post, but i will keep this here.

now that i re-read your post, try doing a Kam reset. Kam is keep-alive memory, and is in charge of remembering basically the conditions to detect a misfire as well as certain timings for ignition. it could be setting a false positive, or you could have an actual misfire, either one could be caused by a sudden change in engine response, like swapping out a clutch

about that "4 cylinders" thing, maybe its just me, but that doesnt sound right. i know Ford has a feature where an engine will run on alternating cylinders if the coolant is over temp, but there is another possible cause. a cross-plane V8 is already not fantastic in balance, but having staggered cylinders like 4 and 7 misfire sounds like it can definitely cause shaking like that, and the engine mounts are not designed to damp that degree of shaking. i will disclaim that the second part about engine balance may be wrong, but it sounds right to me based on what i do know. if someone reading this knows i am wrong, please correct me
 
OP
OP
TOXIC_S650

TOXIC_S650

Member
Joined
Mar 24, 2024
Threads
4
Messages
7
Reaction score
6
Location
Montana
Vehicle(s)
2024 Mustang GT Premium
They said the 4 cylinder mode is a safety feature for a misfiring engine, but then continued to tell me there isnt a fix. I will present these options to them and tell them they should check them during install before tuning the car to prevent some problems after-install. Thank you guys for input.
 

LouG

Well-Known Member
Joined
Mar 11, 2025
Threads
4
Messages
247
Reaction score
226
Location
New Zealand
Vehicle(s)
2025 Mustang GT
By shaking in first gear, does the OP mean when engaging the clutch, or while the car is actually driving in first.
I put a solid disc clutch and lightened flywheel in an MX5 and it became undriveable. Clutch engagement was vicious in the extreme.
 

erocker

Well-Known Member
Joined
Apr 4, 2023
Threads
5
Messages
522
Reaction score
575
Location
Milwaukee, WI.
Vehicle(s)
'24 Mustang GT Premium, '09 Lexus IS250 AWD
If Ford doesn't have a fix for misfires, then they should buy the car back. Keep taking it back, there's lemon laws for these things.
 

roket

Well-Known Member
Joined
Sep 22, 2022
Threads
69
Messages
2,165
Reaction score
3,192
Location
Cave Creek, Arizona
Website
roketgamer.dev
Vehicle(s)
2024 Ford Mustang Dark Horse
If Ford doesn't have a fix for misfires, then they should buy the car back. Keep taking it back, there's lemon laws for these things.
this is true, and sometimes Ford just cant figure it out. i actually had this happen to a customer when i was a service advisor, before i became dedicated to new vehicles. brand new 2024 Escape had random misfires and misfires in the first 1000 revolutions. the technician and Ford just could not solve the issue, and the customer ended up having it bought back, and bought an Explorer instead. she ended up not liking how small an Escape was and wanted an Explorer's size anyways
Sponsored

 
 








Top