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

[AdamCzap]

The mechanic at the GM dealership in Novi, MI today told me that the car's computer recalibrates itself every 7 miles to know what kind of fuel it's using and switch to the appropriate timings.

ur wastin ur timez.

[CamaroSpike23]

Originally Posted by AdamCzap

The mechanic at the GM dealership in Novi, MI today told me that the car's computer recalibrates itself every 7 miles to know what kind of fuel it's using and switch to the appropriate timings.

ur wastin ur timez.

your mechanic doesnt know that for a fact. we've got numerous members who have driven thousands of miles with good fuel in the car and it still hasn't re-calibrated until the fuse pull is performed.

[MikeW]

Does anyone know if LS3 Vette owners are having these type of issues?

[Spaceballone]

Holy rusted HP Batman! I did the pull while giving her, her weekly bath. and the fuses were pulled all of 3 hrs and bam, this thing moves. I must admit i never thought i had a problem, but i did the plug pull and now she screams as i pull her hair! aww love it, would recommend this to any L99 owner!

[Scott@Bjorn3D]

If you pull the fuses and then a couple of weeks later the car is getting slow again you need to change gas stations or gas brands. Your are getting bad gas. The computer will revert to low octane tables as soon as it senses engine knock. So it would slow back down right away. 1 bad tank of gas and she will go into slow mode.

[patriotpa]

Originally Posted by Sean_W

I did the fuse pull about a week ago (L99), but now it seems to be back to where it was befor. Has anyone had to do this pull more than once? I have only put premium in since the pull. I used to put mid (89 is mid where I live, with 91 being the best).

Going to pull again and see what happens. Just out of curiosity, what would happen if these fuses were left out? What exactly do they control?

It helps to get gas at a busy station. Gas loses octane points over time. Fresh gas=higher octane.

[DDustiNN]

Originally Posted by PQ

Glad you're back on the road.

If you can, I'd time it first and then after.

Thanks Pics posted in the ABM thread.

I pulled the fuses last night and left them out for about 14 hours or so I think. My gas mileage has been pretty steady at 18, so I reset it today for my driving. I drove about 70 miles or so, and it still stayed pretty low. It was around 15-16 when I randomly checked it throughout the day. When I parked it tonight after getting home, it was right back around 18 again. I didn't notice any difference. The car still felt just as fast, although I don't have the means to do an accurate timed run.

No complaints here though, since mine didn't feel sluggish to begin with, I was just testing it out hoping for better mpg. I attribute it to my lead foot when the light turns green though Although now I hesitate for a few seconds, even when the light is already green as I approach it... don't need a repeat of 2 months ago

So no luck here, and I didn't suspect a problem, but it was worth a shot

[gmag21]

OK so guys if I get a tune I dont need to pull the fuses right? Tune is the same right? What does a 5/20 pull mean anyways? My L99 is doing like 6-7 second 0-60 its horrible.

Grant

[MikeW]

Originally Posted by gmag21

OK so guys if I get a tune I dont need to pull the fuses right? Tune is the same right? What does a 5/20 pull mean anyways? My L99 is doing like 6-7 second 0-60 its horrible.

Grant

All the fuses in your ECM are numbered. Remove the fuses numbered 5 & 20, let the car sit overnight and replace the fuses. You should notice a difference in performance.

[SGOS252382]

Originally Posted by gmag21

OK so guys if I get a tune I dont need to pull the fuses right? Tune is the same right? What does a 5/20 pull mean anyways? My L99 is doing like 6-7 second 0-60 its horrible.

Grant

.
The fuse pull will clear your current programming and let you basically start over. If your car has been running on the low octane tune, it will really help. Make sure you're running 93 octane or close to it before you do the fuse pull. And make sure you continue to use high octane gas or your car could switch back to the low octane tune.

If you go to a skilled tuner, he can optimize your a/f ratios, shift points, torque managment, etc. But you will also be risking your 100% factory warranty on your engine and tranmission. But the fuse pull is not the same as a "tune."

[gmag21]

Originally Posted by SGOS252382

.
The fuse pull will clear your current programming and let you basically start over. If your car has been running on the low octane tune, it will really help. Make sure you're running 93 octane or close to it before you do the fuse pull. And make sure you continue to use high octane gas or your car could switch back to the low octane tune.

If you go to a skilled tuner, he can optimize your a/f ratios, shift points, torque managment, etc. But you will also be risking your 100% factory warranty on your engine and tranmission. But the fuse pull is not the same as a "tune."

Ok well how do i pull the fuses? I know nothing about cars lol where are the fuses to be pulled located? im noob :(

[SGOS252382]

Originally Posted by gmag21

Ok well how do i pull the fuses? I know nothing about cars lol where are the fuses to be pulled located? im noob :(

Check out page 1 of this thread. It has detailed information with pictures.

[JohnInSoCal]

I wonder if the knock sensors are just too sensitive

[gmag21]

Ok i pulled fuses 2 hours ago; when i put them back in do I uses my fingers and push or use the tool? Also, is it okay to put them back in now?