Fuse Pull: Low Octane Fuel Fix For L99 and LS3. Reset Fuel Map for High Octane Fuel.

[90503]

Originally Posted by techinny

Go back to PQ's video and read on. According to PQ's test and I confirmed it, with the key off, the fuses have no power, we are trying to figure out how the fuse pull works if there is no power to the fuses.

I think just about all of us agree, (or are dilusional) that the fuse pull does work and makes a difference. A couple of us just can't be comfortable with that and leave well enough alone.

OK...got it...thanks...lol....Just a thought (might be useful to your test) I also heard that it takes the ECM a while to "power down" after the car is shut off..???..Personally, I pull the fuses right after the car has been running a while, and it "works" every time...I've pulled the fuses after the car had been sitting unstarted for several days, and noticed no difference...

Hope this adds to the confusion and mystery...lol...If not, please disregard!!...lol

[IndeedSS1]

Since we can scan to see how much the low octane table is being reference, has anyone done this to confirm whether or not the ECM is indeed not able to change the Knock Learn Factor back up once it changes the grreater percentage to the low table?

[techinny]

Originally Posted by 90503

OK...got it...thanks...lol....Just a thought (might be useful to your test) I also heard that it takes the ECM a while to "power down" after the car is shut off..???..Personally, I pull the fuses right after the car has been running a while, and it "works" every time...I've pulled the fuses after the car had been sitting unstarted for several days, and noticed no difference...

Hope this adds to the confusion and mystery...lol...If not, please disregard!!...lol

My car had not been run for a day or two when I did the test, and I did not check to see if they had power after I turned the key on to do something else, hmmmmmmm.

[dekan513]

i dont know if this might help but this is fact, i put a cam in my car and had it dyno tuned , it did good for about a week, then it would miss and back like 2 or 3 times a day for a few months , we couldnt figure it out, well then it started doing it a lil more liek 8 times a day just on hard pulls in low rpm range like 3 or 4 k. i went to the drag strip and on the way home it just started missing like crazy , i had a few buddies look at it and we couldnt figure it out so , i said well ill unplug the battery for a night and see if that helps , Nothing , so i thought about the fuse pull , i did it and let it set all night and it drives like it suppose to, not 1 miss in the last 2 weeks , so i dont know if that helps .

[PQ]

Originally Posted by techinny

Just went out and checked the fuses, key off, meter set on millivolts.........absolute zero!!!! So when do we start drinking PQ?

Stil driknign..............

lol

Originally Posted by 90503

Not sure if you are saying the fuse pull does or doesn't work, but earlier in the thread there was a tsb showing that it indeed was the way to reset the octane table...(as well as making sure it was running on premium)...

Just sayin' it must have jived with some electrical schematic at some point...lol

Well, the TSB calls for a pull of the fuse in the trunk as well as only one of the engine compartment fuses.

Originally Posted by IndeedSS1

Since we can scan to see how much the low octane table is being reference, has anyone done this to confirm whether or not the ECM is indeed not able to change the Knock Learn Factor back up once it changes the grreater percentage to the low table?

I've wanted to spend the money and time to learn it just so I can. I wish we knew.

Originally Posted by dekan513

i dont know if this might help but this is fact, i put a cam in my car and had it dyno tuned , it did good for about a week, then it would miss and back like 2 or 3 times a day for a few months , we couldnt figure it out, well then it started doing it a lil more liek 8 times a day just on hard pulls in low rpm range like 3 or 4 k. i went to the drag strip and on the way home it just started missing like crazy , i had a few buddies look at it and we couldnt figure it out so , i said well ill unplug the battery for a night and see if that helps , Nothing , so i thought about the fuse pull , i did it and let it set all night and it drives like it suppose to, not 1 miss in the last 2 weeks , so i dont know if that helps .

Not at all.

[ZL575 #26]

This is my first post. I have read every post on this thread from the beginning. I have a 2010 LS3 manual with a few add-ons from SLP. I bought the car three months ago used with 515 kms on it, so it wasn't yet broke in - now has 7,000 kms. I believe the fuse pull made my car idle more smoothly and shift easier. I can also say that it is more responsive at low rpms. PQ, I noticed from the video that you have a yellow wire in the fuse box and I wonder what that is for. My car has the same thing and I did not add it.

[f5journal]

OK...this is too weird. Too many that claim it feels better. I am in that boat too, however, it did not ALWAYS seem to work. I agree with PQ in no more butt dyno without timing before after.

But let's add this to the mix. Numerous times I went and got in the car the next morning and turned the ignition key on only to say "dumb ass, put the fuses back in"

??? maybe something in that scenario

[PQ]

Originally Posted by ZL575 #26

This is my first post. I have read every post on this thread from the beginning. I have a 2010 LS3 manual with a few add-ons from SLP. I bought the car three months ago used with 515 kms on it, so it wasn't yet broke in - now has 7,000 kms. I believe the fuse pull made my car idle more smoothly and shift easier. I can also say that it is more responsive at low rpms. PQ, I noticed from the video that you have a yellow wire in the fuse box and I wonder what that is for. My car has the same thing and I did not add it.

That goes to the pump on the SuperCharger. Instead of using the tap that most use I used a double fuse extender.

If your car doesn't have a supercharger I'd guess it has something that needs to come on with the ignition.

Oh, and welcome to the forum.

[90503]

Originally Posted by f5journal

OK...this is too weird. Too many that claim it feels better. I am in that boat too, however, it did not ALWAYS seem to work. I agree with PQ in no more butt dyno without timing before after.

But let's add this to the mix. Numerous times I went and got in the car the next morning and turned the ignition key on only to say "dumb ass, put the fuses back in"

??? maybe something in that scenario

That's sort of the theory I'm going with....lol...As a layman/idiot, I just can't see how pulling fuses on something that is completely "dead" would re-set anything....I believe the ECU has to retain some power even after the key is off for the fuse pull to be effective...Not everything goes "dead" after the key is off...you can play the radio still, the outside lights come on for a short period of time...that sort of thing.....After a while you gotta start over, so to speak...

Probably not a good idea to pull the fuses while the engine is running, but I think it must retain some power after the key is off for it to re-set the table....I have noticed that the fuse pull for me is ineffective after the car has been sitting unstarted for several days...So your turning the key on before putting in the fuses, may be the same difference...hell, I don't know...lol

[f5journal]

There is something to the fuse pull. I've done the battery disconnect in conjunction

After doing the 6-8 times over 2 years, there is no doubt in my mind that something happened to the good on 3 occasions

The crap part is that I now have a tune from Jannetty. I am essentially stock. Reflashing the tune now does the same thing. My car is unlearning something as I drive

[Bucci]

Ok, so i am extremely new to the forum (incredible site and member community by the way...)

I am fascinated by this thread... The statistician in me says there are too many in the sample size that say the fuse pull works (at least one standard deviation) for it to be completely lore...

But at the same time from an engineering standpoint its impossible to have an effect with no voltage being held or passed through....

I just bought my 2010 SS M6 a couple of weeks ago ( 5K miles ) and i am figuring someone put low octane fuel in the car at some point... and I would hate to think I was running on the lower octane schedule...

So, I plan to check the voltage of the fuses immediately after shut down to test the "retained power" theory.

Will report back the results.

[techinny]

OK, just throwing this out of my head and into yours, suppose with the key off, fuses 5 and or 20 are now completing a ground to something (ECM?) and removing the fuses break the ground to a relay, capacitor, or some other magical electrical component that makes this all work. Yes, that came out of a heavy equipment mechanic's fingers, I do understand electrical systems to some degree believe it or not.

And Bucci, thanks for jumping in and willing to help us figure this out.

[90503]

Originally Posted by techinny

OK, just throwing this out of my head and into yours, suppose with the key off, fuses 5 and or 20 are now completing a ground to something (ECM?) and removing the fuses break the ground to a relay, capacitor, or some other magical electrical component that makes this all work. Yes, that came out of a heavy equipment mechanic's fingers, I do understand electrical systems to some degree believe it or not.

And Bucci, thanks for jumping in and willing to help us figure this out.

Tech, maybe it's nothing, but there is a forum with sticky's for manuals,bulletins, etc. PDF tech stuff...might be a schematic buried in there somewhere...

[knitetrain05]

Originally Posted by ZL575 #26

This is my first post. I have read every post on this thread from the beginning. I have a 2010 LS3 manual with a few add-ons from SLP. I bought the car three months ago used with 515 kms on it, so it wasn't yet broke in - now has 7,000 kms. I believe the fuse pull made my car idle more smoothly and shift easier. I can also say that it is more responsive at low rpms. PQ, I noticed from the video that you have a yellow wire in the fuse box and I wonder what that is for. My car has the same thing and I did not add it.

I agree with you.It seems it did that for me too. Smoother idle.