idle dropps at stop lights with ac on and off

[WDE]

I have a 2002 denali with 6.0 and every time you are at a red light the idle will drop down to like 500rpms and I'm clue less on this plz help

 

[livingez_123]

Mine has always idled low. it could be fixed with a tune and raise the idle speed up 700.
Do you have a good battery in it? sometimes when a battery gets to the end of it's useful life they can't hold the 12-14 volts needed to run everything at idle, when the voltage drops so does the fuel pressure.

 

[WDE]

I appreciate the info this is my first denali and was needing help also what fuel do y'all recommend I have been running 93 I just got it yesterday and it a 2002 denali loaded to the max has 100,560miles on it and I gave 4k for it. It is in excellent condition garage kept im guessing it was a vacation vehicle. What are some things gas I need to be aware of with theses SUV

 

[kschumake83]

Not too much to worry about on these things, blend door actuators will probably go bad and don't beat the hell out of the trans. My 02 tahoe Idles at 500 when in gear also so I dont think you are having an issue there. I wouldn't waste my time with 93 unless you have a tune, I mostly run 87 but have been trying 89 lately to see if I can get fuel mileage to increase which does not seem to be working. The octane rating isn't what you have to worry about, its the quality of fuel that makes the difference. I never run wawa, hess, or any grocery store brand fuel, it will end up costing you more in the long run.

 

[WDE]

Thanks for the info

---------- Post added at 03:15 PM ---------- Previous post was at 03:13 PM ----------

Also I only run none ethanol fuel unless on a vacation trip.

 

[kschumake83]

Thanks for the info

---------- Post added at 03:15 PM ---------- Previous post was at 03:13 PM ----------

Also I only run none ethanol fuel unless on a vacation trip.

wish we could get that round here, only thing we can get is e10