Any Sort Of Tsb On Hesitant Acceleration?

[b00001]

I have a 2009 Silverado 1500 with the 5.3 and 6spd trans. Just about to hit 7k miles. I am feeling like the truck is almost mis-firing when I need to get on it, for example when entering the on ramp of the interstate. There is quite a bit of hesitation there, and it feels like something is holding back the power from getting to the wheels. It almost feels like a plug is fouled and the motor is running on 6 or 7 cylinders and then it finally cleans itself up to run on 8.

 

Is this normal? Anyone else feel this? I took a friend out and rolling slowly, 35mph or so, I stomped the accelerator to the floor and it was just pathetic. We both laughed at the anemic acceleration. Was wondering if there was some sort of upgraded official GM "tune" that could be done by the dealer?

 

Thanks!

[impalasspeed96]

Thank GM for that. Its a safeguard to help save the life of the tranny. Its called torque management. Get a tune and itll fix that throttle hesitation quite a bit.

[gaidin43]

I am having the same issue. Even just trying to ginger the throttle in stop and go traffic you end up reving the engine and getting no where when it comes to moving the vehicle. I am pretty light on the petal till the highway, but it bogs down so much people end up pulling in front of me like I am a big rig inching along... it gets old.

[b00001]

I am having the same issue. Even just trying to ginger the throttle in stop and go traffic you end up reving the engine and getting no where when it comes to moving the vehicle. I am pretty light on the petal till the highway, but it bogs down so much people end up pulling in front of me like I am a big rig inching along... it gets old.

 

Yup!

[VMax2007]

<------ Look over there and click on either Black Bear or Wheatley. Problem solved!

[fbachman]

<------ Look over there and click on either Black Bear or Wheatley. Problem solved!

 

 

GM TSB: Customer complains of lack-luster acceleration

 

Vehicles Affected: GMT900 with 6-speed Auto

 

Resolution:

 

Open Internet Explorer

 

Open Google

 

In "Search" type GMT 900 Custom Tune

 

Print Out Search Results

 

Hand to customer

 

Offer to e-mail search results.

 

Charge 2 hours labor.

[TorkFaze]

Thank GM for that. Its a safeguard to help save the life of the tranny. Its called torque management. Get a tune and itll fix that throttle hesitation quite a bit.

 

 

"Thank GM for that"....probably.

 

"....to save the tranny"----nope, guess again.

 

The torque management that is used to smooth out shifts and help the long term trans durability is only during shifts and lasts less than a second (Waaaaaay less than a second in virtually all cases including this maneuver).

 

There are other things going on. Not that knowing that it's likely NOT trans TM makes it any better, but we might as well not keep propogating misinformation.

 

Example: Odds are the highway tip-in/out comments are not gear changes, yet the feeling of TM is still there.

 

My advice: If you don't like it, complain to the dealer. Make sure you are specific about if it's only during shifts or if it's even when the trans doesn't shift. Give as much info as you can. GM gets feedback from the dealers on stuff like this and uses that feedback to decide if we need to do an updated calibration that strikes a different ballance in an area like this.

 

If you elect to get an aftermarket tune, you'd be best served to find a tuner who knows the difference between the types of TM and only goes after the things you don't like. You don't want a tuner who hits a finish nail with a sledge hammer because he didn't know that using a ball peen would damage the wood less.

[VMax2007]

If you elect to get an aftermarket tune, you'd be best served to find a tuner who knows the difference between the types of TM and only goes after the things you don't like. You don't want a tuner who hits a finish nail with a sledge hammer because he didn't know that using a ball peen would damage the wood less.

 

Translation: Do NOT let Jesse Bubb tune your truck.

[cerbomark]

Some of this stuff is so subjective. When some says" poor acceleration" that means different things to different people. I ve had a 07 V max(both tuned , several tuners ,and not tuned) and I don t find the 09 to be any worse. I might even say a bit better with the 6 spd.

[impalasspeed96]

Thank GM for that. Its a safeguard to help save the life of the tranny. Its called torque management. Get a tune and itll fix that throttle hesitation quite a bit.

 

 

"Thank GM for that"....probably.

 

"....to save the tranny"----nope, guess again.

 

The torque management that is used to smooth out shifts and help the long term trans durability is only during shifts and lasts less than a second (Waaaaaay less than a second in virtually all cases including this maneuver).

 

There are other things going on. Not that knowing that it's likely NOT trans TM makes it any better, but we might as well not keep propogating misinformation.

 

Example: Odds are the highway tip-in/out comments are not gear changes, yet the feeling of TM is still there.

 

My advice: If you don't like it, complain to the dealer. Make sure you are specific about if it's only during shifts or if it's even when the trans doesn't shift. Give as much info as you can. GM gets feedback from the dealers on stuff like this and uses that feedback to decide if we need to do an updated calibration that strikes a different ballance in an area like this.

 

If you elect to get an aftermarket tune, you'd be best served to find a tuner who knows the difference between the types of TM and only goes after the things you don't like. You don't want a tuner who hits a finish nail with a sledge hammer because he didn't know that using a ball peen would damage the wood less.

 

 

 

 

The throttle blade only opening to X% is a part of the formulated TM. That is exactly what he is feeling is the factory tuned throttle blade restriction.

[2005LT]

Hope the original poster doesn't mind me adding in to this mix. Since TorkFaze is hanging around here I thought I'd add in my issue because it's another form of "hesitation".

 

Just wanted to run this by you TorkFaze and see if it has to do with the engine or transmission. I know mines the 6.0L w/ 6 speed but maybe you've heard or felt this before with the 5.3? My issue is not when I stomp to the floor and it has to think for a while (mine is quite snappy by the way without much hesitation with the factory tune). It happens when I lightly accelerate in the range of 1000 RPM to 2000 RPM. When I apply throttle to accelerate, either while rolling or from a stop, I get a hitch-like, fluttering hesitation. It's like I'm pumping the gas pedal in & out with one cycle occurring every 1 second or so. Even with the converter locked (say at 37 mph or 60 km/h in 6th gear trying to speed up) I can see the tach "fluttering" a few RPM up and down even though the pedal is being held steady.

 

Not a major issue but something I noticed right away when I bought it. Just thought I'd bring it up.

[gvbhunt]

I get the same thing as you 2005LT but mine is not a 6speed. It is really noticable when the engine is cold. At highway speeds when I notice it I would associate it first with the de-activation of AFM, second time with the unlocking of the TQ (the two surges). From a dead stop I have no idea what could possibly cause it.

[TorkFaze]

I get the same thing as you 2005LT but mine is not a 6speed. It is really noticable when the engine is cold. At highway speeds when I notice it I would associate it first with the de-activation of AFM, second time with the unlocking of the TQ (the two surges). From a dead stop I have no idea what could possibly cause it.

 

Good point and one that I forgot about....it does take a smidge of time to go from V4 to V8 and in a 6-speed, that happens before the 5-2 or 6-2 downshift.

 

Something for 5.3L/6-speed guys to try to see if it's any different (and post results!)...put the shifter in M5 before you do your slap-WOT at 35 mph. This does 2 things....it keeps you out of 6th gear so you know for sure you're starting in 5th and it shuts off AFM as AFM is only active with shifter in D or M6, but non M5 or anything lower than M5.

 

 

TF

[2005LT]

Thanks Brad and TF. That confirms to me that it's just the engine tuning and has nothing to do with the trans. It will flutter while accelerating for 6-8 seconds or more and most noticeable at low RPM while the engine is 'lugging' in V8 mode. Just something I'm coming around to ignoring.

[Irv]

My 09 with the 5.3 and 4 sp does this as well, I hate it!! My 97 with the 5.7 would get up and go with no hesitation, the way it should be!

 

I hate getting on the hwy, it feels like I have an anchor draggin behind me and someone is slowly pulling it in.

Same in traffic, stopped at a light, eveyone goes and gets 5 car lenghts ahead of you in no time, my 97 had no problems keeping up, in fact I could push people if I wanted to which I am sure what people are saying behind me now, "hey buddy, you need a push?"