# 2017 Surging under light accel



## Eddy Cruze (Jan 10, 2014)

Sounds like around the time the Turbo kicks in. Of course now you are going to tell me its a non-turbo.


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## WillL84 (Aug 5, 2019)

No it's the 1.4 turbo lol


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## Slayinit (Jan 8, 2013)

Normal. I think the ECU is constantly adjusting for the best fuel economy which makes for a jittery pull up the RPM range. The best non-mod fix is use 91+ octane fuel and lower your expectations. There are 3rd party tunes available that should remedy this issue. YMMV.


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## 17Hatch6MT (Dec 28, 2015)

I have a manual-trans model. Seems to me, it's a bit weak at lower RPMs until it fully warms up. (I use very light throttle settings until it's warm. Don't know what it would do if I 'mashed' it.) I don't push it beyond what it 'wants' to do. I downshift or wait until the revs climb before 'mashing' it. All the 4 cyl cars I've owned in the past (port injected, nat. asp.) are somewhat like this. Don't want to 'go' until revs are above around 2000. This engine is different in that it pulls pretty well below 2000 rpm (as long as it's fully warmed up.) But again, I don't add more throttle than it seems 'willing' to take at that rpm. I do run premium & top-tier, and that may be making a difference. Usually top 40 mpg (odo miles/pump gallons) per fill-up.


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## jblackburn (Apr 14, 2012)

17Hatch6MT said:


> I have a manual-trans model. Seems to me, it's a bit weak at lower RPMs until it fully warms up. (I use very light throttle settings until it's warm. Don't know what it would do if I 'mashed' it.) I don't push it beyond what it 'wants' to do. I downshift or wait until the revs climb before 'mashing' it. All the 4 cyl cars I've owned in the past (port injected, nat. asp.) are somewhat like this. Don't want to 'go' until revs are above around 2000. This engine is different in that it pulls pretty well below 2000 rpm (as long as it's fully warmed up.) But again, I don't add more throttle than it seems 'willing' to take at that rpm. I do run premium & top-tier, and that may be making a difference. Usually top 40 mpg (odo miles/pump gallons) per fill-up.


The auto feels quite lazy - and shifts HIGH - when cold too.

And yes, the MT Gen 2 is specifically tuned to try to avoid LSPI sub-2000 RPM, which results in a very flat-feeling power curve down low. Peak tq hits at 2000 RPM and it perks up, but the auto definitely has more 1500-2000 RPM grunt.


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## WillL84 (Aug 5, 2019)

I'll just have to get used to it I guess. I was looking at the BNR tunes but $650 ($350 tune and $300 loader) is a lot to spend just to get rid of that surging lol


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## 17Hatch6MT (Dec 28, 2015)

jblackburn said:


> The auto feels quite lazy - and shifts HIGH - when cold too.
> 
> And yes, the MT Gen 2 is specifically tuned to try to avoid LSPI sub-2000 RPM, which results in a very flat-feeling power curve down low. Peak tq hits at 2000 RPM and it perks up, but the auto definitely has more 1500-2000 RPM grunt.


Crap. Like my handle says, I have an MT model. Like being able to cruise at low RPMs. Get amazing fuel economy there. In a different post (by @obermd ) in the Gen 1 forum, seems Gen1 was tuned in just the opposite way -- MT model made peak torque at 1850, AT didn't reach the same peak until 2500. What gives? New engine tuned to avoid LSPI, and it was not a problem on the old one? (Thread cited: https://www.cruzetalk.com/threads/w...ormal-engines-power-curve.244476/post-3250368)

I'm used to it as it is. Like I said, when it's fully warm, it feels like it has good torque all the way down to about 1200. (I mean, compared to 4cyl cars I've driven in the past. I don't ask much out of this at 1200.) I work the throttle like there's an egg between it & my shoe, when below about 2500. Want good economy and to avoid LSPI.


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## jblackburn (Apr 14, 2012)

17Hatch6MT said:


> Crap. Like my handle says, I have an MT model. Like being able to cruise at low RPMs. Get amazing fuel economy there. In a different post (by @obermd ) in the Gen 1 forum, seems Gen1 was tuned in just the opposite way -- MT model made peak torque at 1850, AT didn't reach the same peak until 2500. What gives? New engine tuned to avoid LSPI, and it was not a problem on the old one? (Thread cited: https://www.cruzetalk.com/threads/w...ormal-engines-power-curve.244476/post-3250368)
> 
> I'm used to it as it is. Like I said, when it's fully warm, it feels like it has good torque all the way down to about 1200. (I mean, compared to 4cyl cars I've driven in the past. I don't ask much out of this at 1200.) I work the throttle like there's an egg between it & my shoe, when below about 2500. Want good economy and to avoid LSPI.


Gen 1 was similar - peak tq was 2500 for manual cars


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## 17Hatch6MT (Dec 28, 2015)

Then that other post has it backwards. That sucks; why have a manual transmission if the engine has to be de-tuned for it


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## WillL84 (Aug 5, 2019)

17Hatch6MT said:


> Then that other post has it backwards. That sucks; why have a manual transmission if the engine has to be de-tuned for it


Dodge does it with their trucks. The auto with the Cummins makes more power than the manual


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## Grizzfire (Sep 23, 2019)

I have exactly the same issue with my '18 AT, same motor. Only in 2nd gear, only under light to medium throttle. It's not a single surge, but 2-4 small ones as the engine revs up, and is noticeable enough that a passenger can feel it. It happens consistently when cold, less so after the motor is warm. I'm familiar with driving turbo motors and when they kick in, but this feels very different and inconsistent, but without a turbo gauge, it's hard to tell. If it's the ECU making adjustments as Slayinit mentions, it's odd, especially since it's only in 2nd gear that this happens.


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## WillL84 (Aug 5, 2019)

Grizzfire said:


> I have exactly the same issue with my '18 AT, same motor. Only in 2nd gear, only under light to medium throttle. It's not a single surge, but 2-4 small ones as the engine revs up, and is noticeable enough that a passenger can feel it. It happens consistently when cold, less so after the motor is warm. I'm familiar with driving turbo motors and when they kick in, but this feels very different and inconsistent, but without a turbo gauge, it's hard to tell. If it's the ECU making adjustments as Slayinit mentions, it's odd, especially since it's only in 2nd gear that this happens.


That's the exact same thing I'm getting


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