bumpy idle

Albundy33 · Post by **Albundy33** » Sat Jun 20, 2015 5:38 pm

hey guys i have a 2009 avalnche with the 5.3l 325 LMG motor.
i have installed the diablotune. shut off DOD. shut off top speed limiter and selected the firm shift for tranny.
i have been using 93 octane and it has been a little over 2 weeks of driving now when im in park or at a red light the truck seems to shake a little, or if i give a little gas just going 10mph in my jobs parking lot it seems like it hesitates.
any ideas on what could be causing it?
thank you

Bigtrucklover · Post by **Bigtrucklover** » Sat Jun 20, 2015 6:13 pm

Albundy33 wrote:hey guys i have a 2009 avalnche with the 5.3l 325 LMG motor.
i have installed the diablotune. shut off DOD. shut off top speed limiter and selected the firm shift for tranny.
i have been using 93 octane and it has been a little over 2 weeks of driving now when im in park or at a red light the truck seems to shake a little, or if i give a little gas just going 10mph in my jobs parking lot it seems like it hesitates.
any ideas on what could be causing it?
thank you

So are you saying it was fine for the first couple weeks and now it's idling worse and hesitating? Usually it should get even better as it learns. Could be crappy fuel.

I would data log the areas that your experiencing issues and look to see if there's any knock retard, and how low the spark advance is. Are you positive someone did not add in any 87 octane??

I would also do the LTFTs per the DSLOGREDUX software.

Albundy33 · Post by **Albundy33** » Sat Jun 20, 2015 6:45 pm

I fill my own tank with 93. Yes for the first 100 miles it wasnt happening.
What are LTFT's?

Albundy33 · Post by **Albundy33** » Mon Jun 22, 2015 12:16 pm

Anyone?

Post by **mikel** » Mon Jun 22, 2015 12:17 pm

did it always do this?
does it do it after you return to stock?

Albundy33 · Post by **Albundy33** » Mon Jun 22, 2015 2:03 pm

Only noticed it after first couple weeks of driving. I havnt returned it to stock

Post by **mikel** » Mon Jun 22, 2015 2:16 pm

id try that first, I doubt its tune related.

Albundy33 · Post by **Albundy33** » Mon Jun 22, 2015 3:13 pm

Should i drive it on stock tune so the ecu learns back the fuel trim?

Post by **mikel** » Mon Jun 22, 2015 4:20 pm

yes, Id like you to load the stock tune and see if it has the same issues.

Albundy33 · Post by **Albundy33** » Mon Jun 22, 2015 5:37 pm

I switched it back to stock. I mostly notice it at idle. I turned the truck on while it was still warm and it seems to be the same

bumpy idle

bumpy idle

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