2015 Silverado 5.3

[Imprtkllrz28]

I Experience fuel Knock or Pinging when I floor it from a dead stop or floor it from cruising speed. I am running 87 tune with 91 octane and still have this issue

[misilver]

I had the same problem before I ever even bought the tuner. It was sh*t gas. Ran it till the light came on and filled it up with Shell 93 and It was, and has been all good ever since. Maybe not the same issue, but some gas is terrible if not from a busy station or out in the boonies.

[06MonteSS]

Make sure you are using GOOD gas, it makes a difference... mobil, exxon, sunoco, amoco, bp, chevron are best brands to use, with mobil and exxon being the best..

NEVER use Shell, costco/bj's, mom-n-pop, or no-name brands, as it's crap gas that tends to cause a lot of knock retard and less performance/mpg...

[Imprtkllrz28]

It doesn't seem to matter what fuel I use this truck pings with anything other than stock or modified stock tune. I have made sure my device is up to but no matter what it pings. Again I have no issues with this truck in stock form. Is this becuase im in ca and our fuels have an ethonol Blend?

Make sure you are using GOOD gas, it makes a difference... mobil, exxon, sunoco, amoco, bp, chevron are best brands to use, with mobil and exxon being the best..

NEVER use Shell, costco/bj's, mom-n-pop, or no-name brands, as it's crap gas that tends to cause a lot of knock retard and less performance/mpg...

[mikel]

the 87 tune runs stock timing levels, can you post a log showing this knock activity?

Thanks

[Imprtkllrz28]

Ok I'm making a long trip tomorrow. Retuned truck. What pids do you want me to run that would help show the pinging issue. I still also have a slight almost stall out issue that I reported
On my other post. This is all only with tuner installed on truck.

[mikel]

the default pids will be fine.

[Grjfer]

Is there any relationship to post #2 here https://forum.diablosport.com/viewtopic ... 62&t=63303?

[adam7]

I'm interested in these results as I'm having the same issues (but with a 2009 5.3). I think the gas in my tank when I first installed the 87 octane tune was from Costco, but I've since filled it with 87 from a Shell station

I was trying to understand Lew's post about adjusting the LTFT slopes and wanted to make sure I got this straight. If I want to make the engine run a tad richer, I want to have a negative slope? I was thinking of a 1-2% adjustment to test and see if that reduces/removes the pinging. Is that a good idea/bad idea?

I'm trying to remember what the tuner said when I was looking through the modification parameters, because IIRC, it was at 0% and it showed to the left was leaner and to the right was richer, so as long as I go 1-2% to the richer side that'll be a negative slope, correct?

[06MonteSS]

make sure you select/install tunes from the Tune Vehicle - ADVANCED MODE menu...

and use GOOD 89 octane gas - Make sure you are using GOOD 91/93 octane gas, it makes a difference... mobil, exxon, sunoco, amoco, bp, chevron are best brands to use, with mobil and exxon being the best..

NEVER use Shell, costco/bj's, mom-n-pop, or no-name brands, as it's crap gas that tends to cause a lot of knock retard and less performance/mpg...

[adam7]

I double checked the tune and what I was thinking was changing the slope to -3 (so more fuel overall?) and changing the WOT in each RPM range to +1%-2% (richer) to start. Then logging again.

Also turning off Torque Mgt. (its a 6 speed).

Long story short, I'd rather give it more fuel than retard the timing if the timing is the same as 'stock' with the 87 tune.

[Imprtkllrz28]

Here is my logs. I heard most of the pinging at low rpms. at light throttle

[Imprtkllrz28]

Anyone have a chance to check these out?

[Djxn40]

Anyone have a chance to check these out?

Did you get this figured out? I seem to be having the same problem on my 2016 silverado?

[arkguy2001]

Mine is doing the same thing, but mostly when I get on it. Ive tried switching gas, updating the tuner and nothing helps.
Really considering going to another tuner!