Spark knock
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Spark knock
2007 GMC Sierra 5.3 gas new body style. U7194 with 9r31 I installed the MPG Boost tune and I was getting spark detonation in the lower RPMs. I retarded the timing to -5 still seem to have it so I went back to -7 and it seems worse. I did the data log but of course I have no idea what I am looking at or for. Any help would be appreciated.
Ralph E. Hempen
- mikel
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Re: Spark knock
Honestly not an issue I have ever heard of with that tune.
Can you try one of the 87 octane or other tunes to see if the issue persists?
Can you try one of the 87 octane or other tunes to see if the issue persists?
Mike Litsch
DiabloSport Brand Manager
Diablo Tech support by phone:
561-908-0040
M-F 8:00 AM to 5:00 PM EST
tech@diablosport.com
DiabloSport Brand Manager
Diablo Tech support by phone:
561-908-0040
M-F 8:00 AM to 5:00 PM EST
tech@diablosport.com
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Re: Spark knock
Yes even with the 87 tune I get low RPM detonation. I set the timing on the low rpm setting back to -7 and still have it. Like if I'm on a highway with the cruise set and start pulling up a hill it's sounds awful. Went back to the stock tune and it goes away. Went back to the 87 changed my injector slop. Just drove it 25 miles to work. Cruise set at 65mph long term is at 0.00 and 0.78 still have the detonation when I accelerated. The spark advance shows 32.5. While I'm cruising.
Ralph E. Hempen
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Re: Spark knock
Yes even with the 87 tune I get low RPM detonation. I set the timing on the low rpm setting back to -7 and still have it. Like if I'm on a highway with the cruise set and start pulling up a hill it's sounds awful. Went back to the stock tune and it goes away. Went back to the 87 changed my injector slop. Just drove it 25 miles to work. Cruise set at 65mph long term is at 0.00 and 0.78 still have the detonation when I accelerated. The spark advance shows 32.5. While I'm cruising.mikel wrote:Honestly not an issue I have ever heard of with that tune.
Can you try one of the 87 octane or other tunes to see if the issue persists?
Ralph E. Hempen
- mikel
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Re: Spark knock
the timing adjustment in the tuner is only for WOT.
The 87 tune does not add any timing, so if its knocking on the 87 tune my guess is the AFr is lean, i'd try adding some fuel.
The 87 tune does not add any timing, so if its knocking on the 87 tune my guess is the AFr is lean, i'd try adding some fuel.
Mike Litsch
DiabloSport Brand Manager
Diablo Tech support by phone:
561-908-0040
M-F 8:00 AM to 5:00 PM EST
tech@diablosport.com
DiabloSport Brand Manager
Diablo Tech support by phone:
561-908-0040
M-F 8:00 AM to 5:00 PM EST
tech@diablosport.com
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- Posts: 18
- Joined: Mon Aug 03, 2020 5:44 pm
- Location: Kentucky
Re: Spark knock
Ok. It has 3 different rpm ranges for adjustment to the timing so I just assumed it would be for that range not the wot. I changed the injector slope yesterday evening. -7 . Now at my normal cruising speed the long terms are at 0.0 and 0.78 should I go more negative on the injector slope?mikel wrote:the timing adjustment in the tuner is only for WOT.
The 87 tune does not add any timing, so if its knocking on the 87 tune my guess is the AFr is lean, i'd try adding some fuel.
Ralph E. Hempen
- mikel
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Re: Spark knock
if its still knocking you can try making it a little richer, yes.
Mike Litsch
DiabloSport Brand Manager
Diablo Tech support by phone:
561-908-0040
M-F 8:00 AM to 5:00 PM EST
tech@diablosport.com
DiabloSport Brand Manager
Diablo Tech support by phone:
561-908-0040
M-F 8:00 AM to 5:00 PM EST
tech@diablosport.com
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- Posts: 18
- Joined: Mon Aug 03, 2020 5:44 pm
- Location: Kentucky
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- Posts: 18
- Joined: Mon Aug 03, 2020 5:44 pm
- Location: Kentucky
Re: Spark knock
Ok so I am at -1.56 on both ltft's. Air temp was at 65° I have my injector slope set at -11. Still getting some detonation. Not as bad but still some. ?
Ralph E. Hempen
Re: Spark knock
at 65* intake air temp, your average LTFT's should be at about +1.5%... Also, you can't just install a tune and then do a new log right away... Every time you install/re-install a tune (or disconnect the battery), all of the learned items like idle, airflow, fueling/fuel trims, emissions readiness tests, etc. all get erased/reset... It takes days/150+ miles to be put on for everything to be relearned by the ECM/TCM and settle back in again before you'd be able to do a new data log and get accurate fuel trim data.
06MonteSS / DiabLew Tune
2014 Camaro SS - 2SS, RS pkg., short-throw shifter, NPP perf. exhaust, BMR strut-tower brace, Cold Air Inductions cold air intake
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com -- www.diablocustomtuning.net
2014 Camaro SS - 2SS, RS pkg., short-throw shifter, NPP perf. exhaust, BMR strut-tower brace, Cold Air Inductions cold air intake
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com -- www.diablocustomtuning.net
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Re: Spark knock
Ok I was just going by what you had said in a previous post of yours on making adjustments.
LS1/LS2/LS3/LS4/LS7 etc. - LOGGING, ADJUSTING INJECTOR SLOPE
"After you make an injector slope adjustment, you will want to do another log to verify the average LTFT's again. Drive for about 30 miles to let the adjustment settle in and get re-learned by the ECM, then do another log following the info up in the LOGGING: section above." I had been driving it at least 40 mile before taking another data log.
LS1/LS2/LS3/LS4/LS7 etc. - LOGGING, ADJUSTING INJECTOR SLOPE
"After you make an injector slope adjustment, you will want to do another log to verify the average LTFT's again. Drive for about 30 miles to let the adjustment settle in and get re-learned by the ECM, then do another log following the info up in the LOGGING: section above." I had been driving it at least 40 mile before taking another data log.
Ralph E. Hempen
Re: Spark knock
yeah, that's ollllllld post/info....
06MonteSS / DiabLew Tune
2014 Camaro SS - 2SS, RS pkg., short-throw shifter, NPP perf. exhaust, BMR strut-tower brace, Cold Air Inductions cold air intake
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com -- www.diablocustomtuning.net
2014 Camaro SS - 2SS, RS pkg., short-throw shifter, NPP perf. exhaust, BMR strut-tower brace, Cold Air Inductions cold air intake
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com -- www.diablocustomtuning.net
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Re: Spark knock
Ok so after 200 miles I did a data log. I have the injector slope set at -9 this is what I got.06MonteSS wrote:at 65* intake air temp, your average LTFT's should be at about +1.5%... Also, you can't just install a tune and then do a new log right away... Every time you install/re-install a tune (or disconnect the battery), all of the learned items like idle, airflow, fueling/fuel trims, emissions readiness tests, etc. all get erased/reset... It takes days/150+ miles to be put on for everything to be relearned by the ECM/TCM and settle back in again before you'd be able to do a new data log and get accurate fuel trim data.
Ltft are +0.78 and +0.78
Intake air was at 64.5°
I did notice a big decrease in the spark detonation but it still has some.
Ralph E. Hempen
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