Sponsored

Low RPM stumble

ManBearPig

Well-Known Member
Joined
Sep 14, 2015
Threads
86
Messages
1,128
Reaction score
273
Location
Nashville
Vehicle(s)
2016 GT
I have had my cars almost two years now and up until the last week it was a weekend toy. Any time I drove it, I drove it pretty hard and was never disappointed. Car runs strong and I have no complaints there. However I've now started driving it more regularly, and have been driving in conditions more typical of everyday driving. Traffic and interstate type stuff vs strictly back roads. I've noticed that under certain circumstances, the car will have a slight stumble/hiccup/glitch under acceleration.

For example….rolling along in 3rd gear or so….traffic briefly slows down so you let off the throttle and start coasting but not enough to require downshifting. At around 1200-1500 rpm or so if you moderately roll back into the throttle to accelerate back up to speed, the car will stumble or hiccup slightly before pulling away. Yes-I realize this is not the car's peak power band or even close to it. I'm also well aware that this may not be the most efficient way to drive. These cars are not low-end monsters but they still have plenty of power to accelerate back up to speed without downshifting in these types of everyday situations. It's also pretty inconsistent. Sometimes it reacts fine under these conditions. The car is Lund tuned and I don’t know if it did this on the stock tune because I never really drove the car in these kinds of conditions before. Is this just the nature of the way these cars perform? I know there's probably all kinds of VCT stuff going on and these engines don’t particularly care for low RPM but I'd have to think the car should run smoother than this? FWIW I can watch my ngauge and the car is always adding timing, even in these conditions. Its not like the car is pulling timing and cutting power briefly, this is more like a brief stutter. Anyone else ever experience this?
Sponsored

 

Bluemustang

Well-Known Member
Joined
Nov 6, 2015
Threads
149
Messages
3,897
Reaction score
2,263
Location
Maryland
First Name
Ryan
Vehicle(s)
2015 Mustang Base GT
My car appears to exhibit this behavior sometimes too, also Lund tuned.

Do you have an auto or manual?
 
OP
OP
ManBearPig

ManBearPig

Well-Known Member
Joined
Sep 14, 2015
Threads
86
Messages
1,128
Reaction score
273
Location
Nashville
Vehicle(s)
2016 GT
My car is a manual. I think if it were an auto it would downshift itself under these conditions and this would probably be a non issue.
 

Bluemustang

Well-Known Member
Joined
Nov 6, 2015
Threads
149
Messages
3,897
Reaction score
2,263
Location
Maryland
First Name
Ryan
Vehicle(s)
2015 Mustang Base GT
My car is a manual. I think if it were an auto it would downshift itself under these conditions and this would probably be a non issue.
The reason I asked was mine appears to do this under certain conditions and I feel like it is the torque converter engaging/disengaging the transmission. But sometimes it does it other times it's perfectly fine.:shrug:
 

Gibbo205

Well-Known Member
Joined
Jan 23, 2015
Threads
156
Messages
6,673
Reaction score
2,207
Location
UK
Vehicle(s)
UK 2015 Mustang & BMW E46 M3
Probably just the fuelling slightly out in the 1200-1750rpm range, if you get heavier into throttle it will cure it.
 

Sponsored

OP
OP
ManBearPig

ManBearPig

Well-Known Member
Joined
Sep 14, 2015
Threads
86
Messages
1,128
Reaction score
273
Location
Nashville
Vehicle(s)
2016 GT
I tend to think of lugging as applying more throttle input than the engine can make use of. If it still accelerates reasonably I don't feel it's lugging. I don't drive this car any differently than any of my other manual trans cars and this is the only one to do anything like this. But it's also the most technologically advanced, so maybe that's just how it is?
 

Bluemustang

Well-Known Member
Joined
Nov 6, 2015
Threads
149
Messages
3,897
Reaction score
2,263
Location
Maryland
First Name
Ryan
Vehicle(s)
2015 Mustang Base GT
I tend to think of lugging as applying more throttle input than the engine can make use of. If it still accelerates reasonably I don't feel it's lugging. I don't drive this car any differently than any of my other manual trans cars and this is the only one to do anything like this. But it's also the most technologically advanced, so maybe that's just how it is?
I'm tending to think Gibbo is right. Maybe send Lund a datalog of the occurrence and see what they say.
 

armykyle1 [HACKED ACCOUNT

Banned
Banned
Banned
Joined
Mar 20, 2016
Threads
74
Messages
1,849
Reaction score
620
Location
Gulf Coast
Vehicle(s)
2018 GTPP premium
My did this stock and does it tuned. These engines don't make a lot of torque and require a little more rpm. With a manual, the car can't slip the converter or down shift, so you begin over fueling the engine essentially. At least that's my theory.
 

El_Centenario

5L V8PWR
Joined
Jun 11, 2015
Threads
5
Messages
632
Reaction score
184
Location
Apple Valley , CA
First Name
David
Vehicle(s)
'15 Mustang GT Triple Yellow
My car has been doing the same thing since I tuned it over a year ago. It randomly happens in 3rd gear at about 25 mph when slightly accelerating when making a left or right turn. The only way it will not do it is if I downshift to second to raise the rpm's at 25 mph.
 

soldier989

Well-Known Member
Joined
Mar 26, 2016
Threads
29
Messages
1,129
Reaction score
233
Location
Columbus OH
Vehicle(s)
2017 GTPP Premium
I just got a GT and noticed this happening in 3rd gear, usually when its cold. Far as I know the car has the stock tune, but I did by it slightly used and can't be sure. It only happens in low RPM, which is the range I'm stuck in driving through my neighborhood in the morning.
Sponsored

 
 




Top