07 Yukon 2500 ly6 constant KR issue

[SOTO]

Hey guys first off i hope i attached the files correctly , Newish to hp tuners not here to make more power or anything i purchased hp tuners because 90% of my construction fleet is gas 6.0 2500s and i usually just go in and i THINK i remove all engine tq mngmnt and i usually just do a little more pressure on the trans/ tcc lock up. Anyway this yukon is driving me nuts its pinging and reading KR on 87 oct i cleaned the MAF i ordered new delphi o2 sensors too. I never mess with the spark tables besides i THINK i took out the knock burst knock . Sorry in advance for my ignorance and thank you in advance for any advice.

[5FDP]

Many of these early calibrations have overly sensitive knock sensor settings, many will lessen them to reduce the knock retard picked up.

[SOTO]

Many of these early calibrations have overly sensitive knock sensor settings, many will lessen them to reduce the knock retard picked up.

It’s actually pinging though you can hear it would sensitive knock sensors cause that ?

[GHuggins]

It's most likely carboned up really bad causing the pinging or has another mechanical issue like a clogged or restricted injector. That's if the fuel is good. Sometimes I have to put burst knock back in just for this whilst still leaving the added timing in the main tables - that way it'll pull for sudden snaps, but still have the timing for constant throttle cruise. Unless yours is knocking there too.

[SOTO]

It's most likely carboned up really bad causing the pinging or has another mechanical issue like a clogged or restricted injector. That's if the fuel is good. Sometimes I have to put burst knock back in just for this whilst still leaving the added timing in the main tables - that way it'll pull for sudden snaps, but still have the timing for constant throttle cruise. Unless yours is knocking there too.

No doesn’t seem to ping cruising .. I bet your right about the carbon though, put new plugs in it (OEM) last week and they looked original 180k miles kind of caked up . I’ll probably put some seafoam top end cleaner through it . See what happens .

[Alvin]

Likely carboned up..

But I do a lot of local truck tunes. If the customer insist on 87 there is quite a few of them that end up needing less timing than stock. Typically you'll find it easiest trying to pass with light throttle on the freeway.

[SOTO]

Likely carboned up..

But I do a lot of local truck tunes. If the customer insist on 87 there is quite a few of them that end up needing less timing than stock. Typically you'll find it easiest trying to pass with light throttle on the freeway.

Yea your right about the passing seems to do better with less throttle .. I sea foamed the top end today didn?t make any difference, still pinging and chattering under load I am afraid to do a wot pull . Still got a little over half tank of 87 so I?ll wait to run it down some more before trying 93 . What about Stoich ? Looks like the table starts at 14.6 than down to around 9 ish on e . Should I change the table to like 14.3 across since it isn?t flex fuel ??

[GHuggins]

The best way I've found to remove carbon is this - purchase 2 cans of top engine sea foam and 2 cans of top engine AC Delco foaming top engine cleaner. With the engine idling around 11 or 1200 rpms via ouput controls of the scanner - spray the sea foam first (1 can) then spray a can of the delco focusing on moving the spray around the throttle plate - the delco will usually act like a better scrubber/disolver whilst the sea foam moistens it up. Snap the throttle several times while slowly coming off of idle to begin with then repeat with the next two cans and then go do a good ol wot backyard cleaning using low gears. This will get the large majority of carbon out. If it's really bad you may even wind up getting a chunk of carbon caught in a plug causing a misfire.

I rarely have to pull timing on the 6l's. I change inj timing even with factory cams and torque model to get to downshift quicker if need be not to mention PE settings to get into power better. Mine usually run better wot than they do mid throttle even in the lower rpms. If it's a heavy work truck then your going to need to do some of this. If it's just a run around put put work truck then up to you whether or not to go that far.

Again, willing to bet it's still got carbon built up. Could be junk fuel, but depends on where you're getting your fuel from.

Also if you change your stoic settings for the ethanol fuel you're going to need to recheck your PE and open loop tables - all of these are multipliers of the stoic settings.

[SOTO]

The best way I've found to remove carbon is this - purchase 2 cans of top engine sea foam and 2 cans of top engine AC Delco foaming top engine cleaner. With the engine idling around 11 or 1200 rpms via ouput controls of the scanner - spray the sea foam first (1 can) then spray a can of the delco focusing on moving the spray around the throttle plate - the delco will usually act like a better scrubber/disolver whilst the sea foam moistens it up. Snap the throttle several times while slowly coming off of idle to begin with then repeat with the next two cans and then go do a good ol wot backyard cleaning using low gears. This will get the large majority of carbon out. If it's really bad you may even wind up getting a chunk of carbon caught in a plug causing a misfire.

I rarely have to pull timing on the 6l's. I change inj timing even with factory cams and torque model to get to downshift quicker if need be not to mention PE settings to get into power better. Mine usually run better wot than they do mid throttle even in the lower rpms. If it's a heavy work truck then your going to need to do some of this. If it's just a run around put put work truck then up to you whether or not to go that far.

Again, willing to bet it's still got carbon built up. Could be junk fuel, but depends on where you're getting your fuel from.

Also if you change your stoic settings for the ethanol fuel you're going to need to recheck your PE and open loop tables - all of these are multipliers of the stoic settings.

Thank you for the advice .. I am going to try that this weekend . I?ll stop by the dealer tomorrow afternoon and pick up that top end delco cleaner . She did smoke pretty dang heavy after the sea foam treatment.

[GHuggins]

You have to spray both brands - one to moisten and loosen up while the other does the "scrubbing". With the delco stuff - make dang sure to wear gloves and don't breathe it

Good idea to also cover the fenders with something in case some gets slung by fan or wash off immediately following before driving. It will eat the paint off.

[SOTO]

You have to spray both brands - one to moisten and loosen up while the other does the "scrubbing". With the delco stuff - make dang sure to wear gloves and don't breathe it

Yup got it , I’ll touch back this weekend after I try it . Thanks again!

[SOTO]

Well I tried the delco stuff ($50 a bottle lol) and the sea foam with no luck still has KR stock Tune … I decided run it down to less than a 1/4 tank put in half tank of 93 and took care of almost all the KR besides when it tips in about 1700-2000 rpm it’ll kr 1-2* than randomly in over drive under full load giving in throttle it’ll kr maybe 1*. Did a WOT log that of course I didn’t save and LTFT were about +5 both banks . Think I might try a different mass air from one of the other trucks next . She seems to stumble a little when coming up to temp at idle . Runs great other than that . Guess I’ll just have to keep her on 93 . The delco and sea foam combo did smooth the idle significantly.

[GHuggins]

It's gone up that high per can now :O It was about 20 or 30 the last time I bought some - granted it's been about 5 years... May just be the winter junk fuel. There are some things in the tune as mentioned before that can help, but you may wind up just having to pull some timing if you don't find anything causing the knock.

[5FDP]

Could try 89 octane too, that's always better than 87 octane.

[verlon]

Which cylinders are knocking?

[Alvin]

Well I tried the delco stuff ($50 a bottle lol) and the sea foam with no luck still has KR stock Tune … I decided run it down to less than a 1/4 tank put in half tank of 93 and took care of almost all the KR besides when it tips in about 1700-2000 rpm it’ll kr 1-2* than randomly in over drive under full load giving in throttle it’ll kr maybe 1*. Did a WOT log that of course I didn’t save and LTFT were about +5 both banks . Think I might try a different mass air from one of the other trucks next . She seems to stumble a little when coming up to temp at idle . Runs great other than that . Guess I’ll just have to keep her on 93 . The delco and sea foam combo did smooth the idle significantly.

Really nothing wrong with pulling timing strategically if 87 is what you have to run. I really do a ton of these things.. If it's a mandatory 87 type tune there might be -4 to +8 and up degree timing changes just depending on where your at in the table.. There are spots that they are sensitive like I mention before.. light throttle acceleration on the highway with converter locked and where a downshift would be inappropriate.

But yeah 93 will allow for much better gains.

[SOTO]

It's gone up that high per can now :O It was about 20 or 30 the last time I bought some - granted it's been about 5 years... May just be the winter junk fuel. There are some things in the tune as mentioned before that can help, but you may wind up just having to pull some timing if you don't find anything causing the knock.

Yea I?ve been a little scared to mess with fuel or timing on the work trucks just because I am not knowledgeable enough but since it?s on 93 I might try adding a degree or two till I see some kr . Did remove cat over temp . And I was going to adjust my tire size but in the tire wizard after I put in the new size (31.7) it adjusted the trans gearing too once I went to look at the speedo table . So I didn?t save it and re opened the file . I think final drive says 3.73 and trans says 4.10 but when I adjusted tire wizard it adjusted everything to 3.73 . Like I said I am very VERY novice at this .

[ctsv2011]

i would back the timing off if tuning on 87 and a splash of fuel in pe wouldnt hurt since your enabling it at 1500 rpm
at 90kpa your commanding 12.4 afr whish is fine but the truck could be actually way leaner with the maf not dialed in add in the fact you have a nice amount of timing in it

[SOTO]

i would back the timing off if tuning on 87 and a splash of fuel in pe wouldnt hurt since your enabling it at 1500 rpm
at 90kpa your commanding 12.4 afr whish is fine but the truck could be actually way leaner with the maf not dialed in add in the fact you have a nice amount of timing in it

yea the timing tables are factory . Ill probably just run her on 93 or 89 . Also I changed the pe to command 12 flat . But your right could be much leaner if the maf isnt right.