2017 Yukon shudder/hesitation

[Timothy Symmons]

Hi all! New to the forum and first post: 

 

I have a 2017 GMC Yukon 5.3 SLE 4WD (157k miles) with a hesitation issue. While accelerating under load, the vehicle experiences a slight shudder and acts like it has a very hard time accelerating until it downshifts and the shudder goes away. No trouble codes. Shudder/shake does not persist after letting off the gas pedal. No matter the speed (but it’s worse at highway speeds). The following maintenance was just completed about 1k miles ago to fix unrelated issues- after which this new problem arose. 

 

-New full set of OEM (nominal flow) injectors 

-Intake port cleaning

-Tire rotate & balance

-Added some Lubegard platinum to the transmission fluid

 

Important info:

-Transmission rebuild at 130k miles

-Spark plugs replaced at 130k miles

This really acts like a low fuel pressure problem from experience diagnosing other vehicles, but I am not really sure. 
 

I have attached an image of my most recent graph recording of some PIDs while this issue occurred. Note the circled area since the screenshot was taken while the problem was recreated. 
 

Anybody else have this issue or know what to check for? I included the MAP sensor reading on the graph since I saw one person with this issue reported a faulty MAP sensor being the issue. 
 

[newdude]

On 1/15/2024 at 12:25 PM, Timothy Symmons said:

Hi all! New to the forum and first post: 

 

I have a 2017 GMC Yukon 5.3 SLE 4WD (157k miles) with a hesitation issue. While accelerating under load, the vehicle experiences a slight shudder and acts like it has a very hard time accelerating until it downshifts and the shudder goes away. No trouble codes. Shudder/shake does not persist after letting off the gas pedal. No matter the speed (but it’s worse at highway speeds). The following maintenance was just completed about 1k miles ago to fix unrelated issues- after which this new problem arose. 

 

-New full set of OEM (nominal flow) injectors 

-Intake port cleaning

-Tire rotate & balance

-Added some Lubegard platinum to the transmission fluid

 

Important info:

-Transmission rebuild at 130k miles

-Spark plugs replaced at 130k miles

This really acts like a low fuel pressure problem from experience diagnosing other vehicles, but I am not really sure. 
 

I have attached an image of my most recent graph recording of some PIDs while this issue occurred. Note the circled area since the screenshot was taken while the problem was recreated. 
 

Anybody else have this issue or know what to check for? I included the MAP sensor reading on the graph since I saw one person with this issue reported a faulty MAP sensor being the issue. 
 

 

 

 

Can you monitor Torque Converter Clutch slip speed?  

[Timothy Symmons]

29 minutes ago, newdude said:

 

 

Can you monitor Torque Converter Clutch slip speed?  

Great idea. I’ll try that this evening.

[Timothy Symmons]

8 hours ago, newdude said:

 

 

Can you monitor Torque Converter Clutch slip speed?  

Attached some screenshots of the TC slip speed. Not sure if this is conclusive or not. The freeze frames were taken at the moment I experienced the issue. Note the live data numbers above the graph. 

[chamilun]

Check your O2 sensor also.   Sounds weird but make sure both pre cat sensors are switching properly.  

 

Also I assume you never get a blinking cel or have fuel trim issues