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Discussion Starter · #1 ·
I have noticed that the gas pedal in my QV has about 3/8 to 1/2" of travel (at the very top of the pedal) before the computer sees the movement and begins to accelerate the engine. I have read about this happening with other car models, but I cannot recall if anyone on this forum has mentioned it on the Giulia.

Has anyone else noticed this, and is there a simple fix to remove some of the free travel?
 

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I've noticed the same in my Ti. My old Infiniti Q50 was instantaneous, definitely some lag in the Alfa if you floor it from the a stop.
 

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2018 Q4 with Fiamenghi Ti exhaust, Race Mod, and Tecnico wheels.
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Do you mean a delay in response or free pedal movement; they are not the same thing. It might be possible to adjust the pedal to remove play, if it really is play and not a "no response" to the start of movement of the sensor. If the later maybe a gopedal or similar would help with the later.
 

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Discussion Starter · #4 ·
Do you mean a delay in response or free pedal movement; they are not the same thing. It might be possible to adjust the pedal to remove play, if it really is play and not a "no response" to the start of movement of the sensor. If the later maybe a gopedal or similar would help with the later.
I'm referring to free pedal movement. When I have some time I'm going to remove it to see if it's possible to add some shims. I'm also unhappy with the lackluster throttle response when starting out from a standing start, but that's a different issue. I tried a go pedal, but I think it can only be fixed with an ecu tune.
 

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Try various driving modes. In 'A' there is a lot of play in the pedal -- and it's on purpose, in Race there is none, at least in my car. Of course it's not about mechanical play, it's only the way throttle reacts. If there is mechanical play, it should probably be checked by the service or at least compared to some other Q.
 

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Discussion Starter · #6 ·
Today I removed the electronic accelerator pedal to see if there was an opportunity to eliminate the free travel that I have observed before the engine rpm responds. I found a rubber stopper that appeared to control the end of travel for the pedal, so I pried the stopper off and replaced it with a new one that I made from a piece of rubber material that I had on hand. I then went for a test drive, and the driving experience was night and day better compared to how the car drives with the regular stopper. It was so nice to get an immediate response when I stepped on the gas pedal. This proved to me that a big part of the lag that I have been complaining about is due to free travel in the gas pedal. I was feeling pretty good about the fix until the check engine light came on. So apparently the computer can "see" the full travel of the gas pedal, but for some reason it will not immediately respond when the pedal leaves the "closed throttle" position.

This is so frustrating. Surely one of the aftermarket companies such as GOMADNESS or Eurocompulsion could come up with a fix for this? There is no excuse that Alfa Romeo would design such a great car, and then saddle it will a crappy throttle setup. So I'm back to square one. I have reinstalled the original bumper and cleared the codes.
 

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This hack is really interesting. Changing the stopper improved things? I guess I can't picture it. I floor the pedal, I mean it's on the floor, and there is a pause/hesitation before the engine responds.

How does a different stopper make a difference?
 

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This hack is really interesting. Changing the stopper improved things? I guess I can't picture it. I floor the pedal, I mean it's on the floor, and there is a pause/hesitation before the engine responds.

How does a different stopper make a difference?
I previously hypothesized that while at a standstill depressing the throttle slightly (not enough to make the engine rev significantly) while holding the brake would give a better launch than simply flooring the throttle. I posted that together with some other info and got 2 responses of "it did not work", leaving me uncertain which of the items that I posted did not work. It sounds like this trick does work to reduce the delayed throttle response. My guess is that you are signaling the ECU to "stop trying to conserve fuel and get ready to go" by putting down the throttle so slightly.

I don't know how difficult it would be for gopedal (or similar) to do something similar. This only makes sense to do when the vehicle is at a full stop.

Still waiting for my ordered car to arrive so I can try stuff like this myself...
 

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Discussion Starter · #9 ·
This hack is really interesting. Changing the stopper improved things? I guess I can't picture it. I floor the pedal, I mean it's on the floor, and there is a pause/hesitation before the engine responds.

How does a different stopper make a difference?
I agree that there is a pause or hesitation when you aggressively floor the gas pedal. The only way I have found to launch the car without holding the brake at the same time is to just squeeze the gas pedal and go. Flooring it seems to confuse the computer. That is something that I'm not happy about, but it is different from what I was attempting to solve with the homemade stopper.

With the homemade stopper (which threw a check engine light) the engine would respond immediately when you are coasting a little bit, and you decide to add some gas to speed up a little. With the factory stopper it always feels as if there is a dead spot at the beginning of the gas pedal movement before the engine responds. (And there is indeed an actual dead spot.) With the homemade stopper everything felt more immediate during the test drive.

What you are talking about is the other thing that I'm not all that happy about. It seems as if the engine has been severely limited in torque output at low rpm's when you start out from a standing start, such as when the light turns green. I don't think the problem is with the engine or turbos, but instead its a choice that was made in how they programmed the ECU.

After my experience today with the homemade stopper, I am certain that there are two things going on that are contributing to my dissatisfaction with the throttle response. One is the dead spot at the beginning of travel, which is most annoying when you are underway and you just want to feather the throttle a little bit with more or less throttle. And the other is the lack of torque that the engine will provide at low rpm's when you are coming off of idle.

To see if your car has a dead spot, just start the car in your driveway and then get out and get on your knees while you reach in to push the gas pedal with your hand. You can watch both the gas pedal and the tachometer at the same time. If you have a dead spot you will observe that the pedal has to move a significant distance before the engine rpm's start to climb.
 

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This hack is really interesting. Changing the stopper improved things? I guess I can't picture it. I floor the pedal, I mean it's on the floor, and there is a pause/hesitation before the engine responds.

How does a different stopper make a difference?
I am having same problem understanding how stopper changed the behavior of the pedal in initial few mm,

I guess he is saying that because he can not floor the pedal completely (because of larger stopper) car supposedly reacts differently....

I don't know **** but in my view Giulia operates like any orher car I have ever driven, there is some play in all pedals whether electronic or fully mechanical....and I tend to floor the gas pedal in progressive fashion not bang all the way in in a milisecond
 

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Discussion Starter · #11 ·
I am having same problem understanding how stopper changed the behavior of the pedal in initial few mm,

I guess he is saying that because he can not floor the pedal completely (because of larger stopper) car supposedly reacts differently....

I don't know **** but in my view Giulia operates like any orher car I have ever driven, there is some play in all pedals whether electronic or fully mechanical....and I tend to floor the gas pedal in progressive fashion not bang all the way in in a milisecond
To see first hand what I am talking about, start the car in your driveway and then get out onto your knees and push the gas pedal with your hand. You can watch both the gas pedal and the tachometer at the same time, and if there is a dead spot at the beginning of travel you will observe that the pedal has to move a significant distance before the engine rpm's finally start to climb.

(BTW, the homemade stopper had nothing to do with flooring the gas pedal. That is a separate issue.)
 

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Ok, I did the test. Got on my knees and pushed the pedal with my hand, observing the tachometer.

There is zero perceptible play on my accelerator (Q4).

However, whether I floor the accelerator, and I do mean to the floor, or simply depress it slightly to move away from a red light, or depress it halfway to speed away from stop sign to beat traffic across a street, there is a perceptible, and, to me at least, unacceptable delay in response from the engine which translates to vehicle motion.

I've owned a lot of cars, and driven even more including rentals at airports as I travel, and this delay is more than any of those. It stands apart on its own.

From a safety point of view, as I drive, I've had to remember I'm driving a car that doesn't immediately begin to respond to my throttle input.

It does feel like a computer issue, but I'm not ruling out really bad turbo lag.
 

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Discussion Starter · #13 ·
Ok, I did the test. Got on my knees and pushed the pedal with my hand, observing the tachometer.

There is zero perceptible play on my accelerator (Q4).

However, whether I floor the accelerator, and I do mean to the floor, or simply depress it slightly to move away from a red light, or depress it halfway to speed away from stop sign to beat traffic across a street, there is a perceptible, and, to me at least, unacceptable delay in response from the engine which translates to vehicle motion.

I've owned a lot of cars, and driven even more including rentals at airports as I travel, and this delay is more than any of those. It stands apart on its own.

From a safety point of view, as I drive, I've had to remember I'm driving a car that doesn't immediately begin to respond to my throttle input.

It does feel like a computer issue, but I'm not ruling out really bad turbo lag.
That's interesting that your Q4 doesn't have any free travel before the rpm's start to increase from idle.

It's possible that the lag problem you are describing is worse than anything that I have experienced with my QV. You might try just squeezing the gas pedal rather than giving it a sudden and aggressive push. That seems to work best on my QV.
 

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No perceptible travel before the rpm's react, as it should be. It's really easy to see this since it's one's hand applying slow and steady pressure, instead of your foot, through a shoe. Great test!!

Come to think of it, given what I observed, it's not the throttle at all. I'm beginning to think it's probably the computer that's causing the delay before the car moves...somehow.

I'll try squeezing gently tomorrow. I'm also toying with the idea of disconnecting the negative battery terminal to reset things, but I'm concerned of negative (no pun intended) consequences, like lost codes or giving Alfa a reason to blame me for these issues.
 

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This really sounds like a go pedal (or similar) on an aggressive setting would help speed up the signal from the pedal sensor to the Ecu.

Not all gopedals are created equal, you may need to try 2 or 3 brands to find one you like.
 

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Ok, I tried the squeeze technique this morning. Just to make sure I minimized variables, I started the car and let it idle for two minutes before engaging the transmission.

Indeed, gently squeezing the accelerator prevented any hesitation from showing up. This was similar to when I used my hand to depress the accelerator steadily while watching the rpm's: the rpm's immediately reacted to any pressure, with no perceptable play in the pedal mechanism, and no delay in the rpm increase.

Once I got out of the neighborhood and into more traffic, things were different. After pulling into a store to make a u-turn, as I was reentering the main street, I misjudged the speed of an oncoming van (which was obviously speeding on a Sunday morning). Having committed, I had no choice but to continue steadily squeezing the pedal, but I squeezed further to accelerate more quickly. That's where the hesitation became evident again. In fact, unless I'm mistaken, it felt like the power was going up, then something kept it down or brought it down, then as more time elapsed, the power slowly began to build and finally it really skyrocketed, but too late to avoid the other car having to slow down to avoid crashing into me (and of course he used his horn to let me know).

For some reason, the power delivery from a stop is non-linear, if you need more than minimal acceleration. I had the setting on Dynamic, by the way. The fact that it is so non-linear leads me to conclude that it's not simple turbo lag; I think it's engine-management related.

My difficulty starting the engine when it's been sitting for a few hours started when the dealer installed the two updates (060 and 043 rev. C). I'm thinking that may have something to do with this, but that's only a guess.

I guess I have to find time to leave it at the dealer again.

My Q4's thermometer read 87 degrees F when I first started it at 0800 hours this morning, by the way (housed in a hot garage). Outside temperature during my test was 79 degrees F. It's still warm here in the southwestern United States!
 

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Discussion Starter · #18 ·
Ok, I tried the squeeze technique this morning. Just to make sure I minimized variables, I started the car and let it idle for two minutes before engaging the transmission.

Indeed, gently squeezing the accelerator prevented any hesitation from showing up. This was similar to when I used my hand to depress the accelerator steadily while watching the rpm's: the rpm's immediately reacted to any pressure, with no perceptable play in the pedal mechanism, and no delay in the rpm increase.

Once I got out of the neighborhood and into more traffic, things were different. After pulling into a store to make a u-turn, as I was reentering the main street, I misjudged the speed of an oncoming van (which was obviously speeding on a Sunday morning). Having committed, I had no choice but to continue steadily squeezing the pedal, but I squeezed further to accelerate more quickly. That's where the hesitation became evident again. In fact, unless I'm mistaken, it felt like the power was going up, then something kept it down or brought it down, then as more time elapsed, the power slowly began to build and finally it really skyrocketed, but too late to avoid the other car having to slow down to avoid crashing into me (and of course he used his horn to let me know).

For some reason, the power delivery from a stop is non-linear, if you need more than minimal acceleration. I had the setting on Dynamic, by the way. The fact that it is so non-linear leads me to conclude that it's not simple turbo lag; I think it's engine-management related.

My difficulty starting the engine when it's been sitting for a few hours started when the dealer installed the two updates (060 and 043 rev. C). I'm thinking that may have something to do with this, but that's only a guess.

I guess I have to find time to leave it at the dealer again.

My Q4's thermometer read 87 degrees F when I first started it at 0800 hours this morning, by the way (housed in a hot garage). Outside temperature during my test was 79 degrees F. It's still warm here in the southwestern United States!
Even though my car is a QV with the V-6, I think both of our cars behave the same when the accelerator pedal is pressed aggressively. It's possible that the electronic stability control system is too aggressive, but just like you I think it's how the ECU has been programmed. Unlike most cars with an automatic transmission, I can't even get a little head snap when I'm starting out from a dead stop.
 

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Yeah, but you have a QV! :)

I'll take the same problem in a QV please...
I believe that Eurocompulsion is claiming that their soon to be released ECU upgrade will resolve this issue for the 2.0T.
A mode: no change (to maintain the car's high fuel economy)
D mode: claimed instant (or at least greatly improved) responsiveness

All of my current vehicles have some form of hesitation. For the Protege and Truck if I rev the engine a lot before engaging the clutch I can work around it, although the diesel truck takes forever to rev even with no load on the engine. For the Crosstrek it is simply lazy to respond until it gets reved up, then it want to keep the fast response and high revs long after I no longer want it.

That is on the Crosstrek merging onto the freeway: floor it, count to 3 engine finally runs up redline and the car goes. Match traffic speed and ease off pedal but the engine stays near the redline for 1-2 seconds and vehicle speed drops rapidly. Start swearing and tapping the upshift paddle... It's my wife's car so I don't drive it enough to get used to how to work around it.

The point of the story being that responsiveness issues are not unique to Giulia.
 
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