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[mitchntx]

You running a custom tune or is everything bone stock?

Stock

 

[TexMex247]

You running a custom tune or is everything bone stock?

That was also my next question. By design, just about every automatic transmission out there is an RPM based liquid clutch. Things like torque converter lock-up are usually TCM(trans computer) controlled or strictly RPM based. If it bucks on accel, you may need a TCM update. Without looking at real time transmission and engine sensor data, it's hard to jump to any conclusions.

The other factor may be any plug-in's run through the DLC or OBDII connector. If you are using any devices that plug in there, it might be making your PCM unhappy. Things like insurance company monitoring devices may produce undesired side effects.

Also, a bunch of GM vehicles use a throttle by wire setup or APP sensors. They can produce symptoms that seem like transmission problems when they are really just sending conflicting information to your cars computer. Most sensor correlation problems also produce engine codes specific to them or "engine power reduced" messages.

Unfortunately, your problem may have to get worse before it can be accurately diagnosed.

 

[mitchntx]

I feel if they would just log some data, the problem would be obvious.
Buncha hacks ...

I've plugged nothing into the OBD port.

The LQ9 is definitely a TBW setup.

Later will be too late for warranty work ...

Thanks for helping, though.

 

[TheDan]

Also, a bunch of GM vehicles use a throttle by wire setup or APP sensors.

That was going to be my guess. Mitch, did you buy it new or used? If used a doofus PO might have put a "throttle booster" on it. Could just be a flaky pedal sensor, too.
Oh, turn the dang TC off... You don't need that


Hey Tex, here's a modern car question for you... 2012 Abarth... Sometimes on hot days when I'm running up to redline the tach will freak out and then only register about 30% of normal. All other gauges are still fine; no CEL. Turning off the car and back on clears the issue (maybe it runs Windows). It only ever happens on really hot days, like 100° or more. You see any service bulletins about that or have any other ideas?

 

[mitchntx]

That was going to be my guess. Mitch, did you buy it new or used? If used a doofus PO might have put a "throttle booster" on it. Could just be a flaky pedal sensor, too.
Oh, turn the dang TC off... You don't need that

Purchased new. It is unmolested except for Bilstein shocks.

Without TC, the back tires would be bald.

Only way to sorta prevent it happening is to roll away at idle for 2 or 3 seconds and it isn't as noticeable.
But idling away for 3 seconds, in traffic, is an eternity.

Mustangs, from the 2010 or so era, had a pesky delay built into the TBW set up.
When these unit began hitting road courses, drivers were complaining about how the delay in throttle response was getting them into trouble
when trying to lay down power to get weight transferred to the rear of the car for traction.
The delay was all about driveability for inept drivers, a much needed attribute for your typical Mustang owner.

At first, I thought that it might be something similar. But it only happens after coming to a stop and off idle.
I can power brake it and throttle response is fine ... but I'm too old to play those childish games

 

[TexMex247]

Sorry that's all I got for ya Mitch. Definitely not what I would call normal but I really don't see many of those come in.

Dan, as far as your Abarth, there are several bulletins about PCM updates for erroneous codes. Those would obviously illuminate your CEL. There is also even an update for your dash clock gaining or losing time, so don't think you're crazy if it seems to change from day to day.

As far as your tach, it uses a stupid can-bus system instead of wiring directly to or from a crankshaft or camshaft sensor. Even a glitch within your BCM(kinda the Can-Bus hub) can/will cause that and should store a U or B series code. You might be able to pull it with an aftermarket scan tool but most of them don't provide a BCM interface.

 

[TexMex247]

Also no service bulletins about your tach but plain and simple, resistance increases with temperature and most car makers are dumb enough to put PCMs and BCMs in the engine compartment now. You can also check the ground wire behind your left kick panel near where you braking foot would typically rest.

 

[scap99]

Purchased new. It is unmolested except for Bilstein shocks.

Without TC, the back tires would be bald.

Only way to sorta prevent it happening is to roll away at idle for 2 or 3 seconds and it isn't as noticeable.
But idling away for 3 seconds, in traffic, is an eternity.

Mustangs, from the 2010 or so era, had a pesky delay built into the TBW set up.
When these unit began hitting road courses, drivers were complaining about how the delay in throttle response was getting them into trouble
when trying to lay down power to get weight transferred to the rear of the car for traction.
The delay was all about driveability for inept drivers, a much needed attribute for your typical Mustang owner.

At first, I thought that it might be something similar. But it only happens after coming to a stop and off idle.
I can power brake it and throttle response is fine ... but I'm too old to play those childish games

From a Ford perspective we pull battery cables and press the brake pedal to clear the Keep Alive Memory.
Also, there might be a pedal relearning procedure.

Like I said, not sure if that is applicable to GM, but might be worth a shot.

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[TheDan]

I've got a scanner that is supposed to be can-bus, but catching the issue might be tough. It always clears on restart. Everything goes through the can-bus including the boost gauge. All the gauges are just displaying an approximation of what the computer expects the car to be doing. Definitely not how I would have designed it

...and yeah, my clock does gain time. I just reset it every so often

 

[TexMex247]

Hey Outdare, just saw your post a couple pages back. My first thought would be that your evaporator core is slowly leaking freon. As it leaks it carries a small amount of oil with it. It has an ususual chemical smell to it. Almost musty but ozony is also a good description. You would need a halogen gas leak detector to know for sure. In time, if that is the case, you will seen an obvious decline in your acs performance.

You can also check your fresh air cowl to make sure there's not a bunch of moldy twigs and organic matter caught up just below your windshield. Lastly, make sure your evap core drain tube drips or flows at a steady rate when your A/C is on and cooling well. A plugged drain will create mold on the core pretty quickly.

My gut tells me it is still most likely a slow leak at the core. Freon is more dense than ambient air and will settle like a chemical cloud in the evap case then blast you in the face when you first turn it on.

 

[Savage20]

I'll be the first. Almost time to replace my battery - 2011, F-150 V8. Who is making the best battery nowadays?
(I've heard NAPA - what's your opinion?)

Avoid Optima. Their quality has dropped in the past decade and they're just milking that name recognition. Save a few bucks and get a DieHard Platinum.

 

[TexMex247]

Avoid Optima. Their quality has dropped in the past decade and they're just milking that name recognition. Save a few bucks and get a DieHard Platinum.

Same deal with interstate but you kinda just have to pick your poison. Local with best warranty will usually get my vote.

 

[Savage20]

Yup, that's why I recommend DieHard Platinum. That's all I will use in my work and personal vehicles now. Even the boats.


Mitch, is that Chevy the first GM you've had with DBW? Their trucks have really bad delay in the skinny pedal.

 

[mitchntx]

Mitch, is that Chevy the first GM you've had with DBW? Their trucks have really bad delay in the skinny pedal.

A custom tune eliminated the delay on the Mustangs.
I'm thinking seriously about a Black Bear tune to help the transmission while towing my RV.

Had an 8.1/Alli that was DBW and now own a CTSV with an LS3/T56.
I don't factor in the V because its a stick, but have replaced the accelerator pedal assembly.
And with Texas Driving Experience at TMS I drove a variety of C5s and C6s, Mustangs and Mazda Speed 3s ... both manuals and autos.

So I have seat time with GM DBW, but limited on the truck side.

 

[mitchntx]

I'll be the first. Almost time to replace my battery - 2011, F-150 V8. Who is making the best battery nowadays?
(I've heard NAPA - what's your opinion?)

Like stated, almost all batteries come from a handful of manufacturers ... kind of like AR lowers.
The deciding factor for me is where to go for warranty consideration.

There is a Wal-Mart in every po-dunk town now and typically a NAPA, Autozone and O'reilly's.
They are open late/all night and all weekend.

NTB/Sears, shops with Interstate and some of the others, its hit or miss.

And when I need a battery and I'm travelling ... that's not the time to have to wait till Monday morning.

So buy peace of mind ... durability or replaceability.

 

[scap99]

A custom tune eliminated the delay on the Mustangs.
I'm thinking seriously about a Black Bear tune to help the transmission while towing my RV.

Had an 8.1/Alli that was DBW and now own a CTSV with an LS3/T56.
I don't factor in the V because its a stick, but have replaced the accelerator pedal assembly.
And with Texas Driving Experience at TMS I drove a variety of C5s and C6s, Mustangs and Mazda Speed 3s ... both manuals and autos.

So I have seat time with GM DBW, but limited on the truck side.

The pedal on my old 06 felt dead pedal feel, but it was too gutless to snap heads back.

Black Bear is the goto guy for tunes. Definitely give him a shout.



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[Savage20]

A custom tune eliminated the delay on the Mustangs.
I'm thinking seriously about a Black Bear tune to help the transmission while towing my RV.

Had an 8.1/Alli that was DBW and now own a CTSV with an LS3/T56.
I don't factor in the V because its a stick, but have replaced the accelerator pedal assembly.
And with Texas Driving Experience at TMS I drove a variety of C5s and C6s, Mustangs and Mazda Speed 3s ... both manuals and autos.

So I have seat time with GM DBW, but limited on the truck side.

Any halfway decent tune can dial back the torque management which will help with shift performance, but if you do any serious towing I would leave it alone in the Tow Haul mode. You can adjust settings in and out of Tow Haul. Anyway, there's no easy tune for dialing out the delay in the throttle which is what I think you're experiencing off the line. Anybody that's made a career out of fine footwork and throttle response will find the delay absolutely offensive. But most people don't even notice it.

On the Chevy trucks, it's horrendous. In my 6.0 1/2ton I have the same problem. The only fix is to just not be so impatient with the throttle response. Gotta drive it like a Duramax with bad turbo lag. Just ease into it and give it a few seconds to react. lol


ETA: torque management only pulls it back during shifts and has nothing to do with starting off idle, so a Black Bear tune won't fix your issue. But, those 6.2s LOVE a good tune and you should even pick up some fuel economy. By dialing back the torque management even 20% it makes the truck feel 50hp faster. No more sluggish shifts.

 

[Sugar Land]

TM247 this is one of the best threads I have seen in a long time. Thank you.

 

[scap99]

Any halfway decent tune can dial back the torque management which will help with shift performance, but if you do any serious towing I would leave it alone in the Tow Haul mode. You can adjust settings in and out of Tow Haul. Anyway, there's no easy tune for dialing out the delay in the throttle which is what I think you're experiencing off the line. Anybody that's made a career out of fine footwork and throttle response will find the delay absolutely offensive. But most people don't even notice it.

On the Chevy trucks, it's horrendous. In my 6.0 1/2ton I have the same problem. The only fix is to just not be so impatient with the throttle response. Gotta drive it like a Duramax with bad turbo lag. Just ease into it and give it a few seconds to react. lol

I'm sure there is a parameter for throttle tip in, which could be adjusted to make the truck feel lighter off the line.

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[Savage20]

Sorta. It's a combination of different parameters that will help get you your throttle response.