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

[PQ]

[QUOTE=Warr3nc;852713]

Originally Posted by Blueclyde

I found this in the owners manual section on GM's SI website. So one would really think the dealers would know better to put 87 in the V-8's.
Recommended Fuel

If the vehicle has the 3.6L V6 engine (VIN Code V), use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, an audible knocking noise, commonly referred to as spark knock, might be heard when driving. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If heavy knocking is heard when using gasoline rated at 87 octane or higher, the engine needs service.

If the vehicle has the 6.2L V8 engine (VIN Code W) or the 6.2L V8 engine (VIN Code J), use premium unleaded gasoline with a posted octane rating of 91 or higher. For best performance, use premium unleaded gasoline with a posted octane rating of 93. You can also use regular unleaded gasoline rated at 87 octane or higher, but the vehicle's acceleration could be slightly reduced, and a slight audible knocking noise, commonly referred to as spark knock, might be heard. If the octane rating is less than 87, a heavy knocking noise might be heard when driving. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. Otherwise, you could damage the engine. If heavy knocking is heard when using gasoline rated at 87 octane or higher, the engine needs service.

I just read the knock sensor description and operation on the SI website as well so it makes me think this whole problem while caused by the dealers was compounded by some programming issues too. I could paste the knock sensor description if anyone would like to read how that system works.

Great find man.

But I would change that from 'slightly' to 'significantly'

Either way I feel vindicated.

[Warr3nc]

Oh yeah considering the numbers I saw from some of the L99's, 'significantly' would definitely fit the situation better. Glad I could help.

[Ject]

Originally Posted by Bell040

u runnin 93 octane?

yup

[ls2gto]

[QUOTE=irpq11;852760]

Originally Posted by Warr3nc

Great find man.

But I would change that from 'slightly' to 'significantly'

That's what still does not make sense to me. 87 is only supposed to reduce the acceleration slightly not significantly AND using 87, if it is all you can find, is not supposed to require reset of the computer when you go back to premium.

My G8 came with 87 and it definitley seemed to smooth out and perk up soon after I filled it with 93. I was in it hard tonight and there is no way the 0-60 time is 6.0 or higher. However, there is also no way I gained 100 hp by adding 93- that's like adding nitrous.

[Warr3nc]

[QUOTE=ls2gto;853631]

Originally Posted by irpq11

That's what still does not make sense to me. 87 is only supposed to reduce the acceleration slightly not significantly AND using 87, if it is all you can find, is not supposed to require reset of the computer when you go back to premium.

My G8 came with 87 and it definitley seemed to smooth out and perk up soon after I filled it with 93. I was in it hard tonight and there is no way the 0-60 time is 6.0 or higher. However, there is also no way I gained 100 hp by adding 93- that's like adding nitrous.

Yeah very true. I posted in another thread the description and operation of the knock system and it is supposed to advance and retard the timing as needed. I think this is just a programming issue that caused the PCM to stay in the low octane table. I also read that the timing b/t the high and low tables was up to 16 degrees which is quite a bit of accel. GM will come out with an update soon. I see the updates for the A/C compressor are out as well as updates for the multimedia accessories.

[ls2gto]

[QUOTE=Warr3nc;853684]

Originally Posted by ls2gto

Yeah very true. I posted in another thread the description and operation of the knock system and it is supposed to advance and retard the timing as needed. I think this is just a programming issue that caused the PCM to stay in the low octane table. I also read that the timing b/t the high and low tables was up to 16 degrees which is quite a bit of accel. GM will come out with an update soon. I see the updates for the A/C compressor are out as well as updates for the multimedia accessories.

Yeah my guess is that more than just the octane is involved here, but it all gets corrected, at least for a while, by the fuse pull.

[Keith Kinkaid]

Just finished burning the last 1/4 tank of 87 octane gas out of my car, I ran up and down the interstate for about 2 hrs. just letting it loose, even caught a guy in a challenger and played with him :-) I was dusting him for a minute until neither one of us could go any futher....to much traffic on the interstate. When I got up to about 105 mph my ears started popping like I was on an airplane (lol). I filled it up with Exxon 93 octane ($46.00 to fill it up...Damn) and took it home and pulled the fuses, will let everyone know the results tommorrow.

[PQ]

Originally Posted by Ject

yup

Any better?

Originally Posted by Keith Kinkaid

Just finished burning the last 1/4 tank of 87 octane gas out of my car, I ran up and down the interstate for about 2 hrs. just letting it loose, even caught a guy in a challenger and played with him :-) I was dusting him for a minute until neither one of us could go any futher....to much traffic on the interstate. When I got up to about 105 mph my ears started popping like I was on an airplane (lol). I filled it up with Exxon 93 octane ($46.00 to fill it up...Damn) and took it home and pulled the fuses, will let everyone know the results tommorrow.

L99?

[19K3SS]

So I'm thinking of doing this, even thou I have an LS3. I had my car dyno'ed a couple weeks ago, was putting down around 350 at the wheels. Just for kicks I was gonna get it dyno'ed again since I got the GMPP exhaust, to see if there really was any difference. Maybe after that, I'll pull the fuses... Would be interesting to see what difference it makes if I dyno it after pulling the fuses... (the car does not seem slow at all, but I did have to use 91octane one day, as opposed to the normal 93 I put in it... and I'm just curious to see if I'd get even more out of it by doing it!)

[orange_5thgen]

First mine is an LS3. I've been reading this thread for a few days and I figured pulling the fuses would not hurt anything. I have noticed it idling a little rough, but have not done any 0-60 times etc....

Now I've driven a few different standard/manual vehicles in my time, but I'll be damned if I have not had trouble driving this car. I figured I was just out of practice and this is not my daily driver, SO makes sense that I do not drive it every day. I've had a lot of jerky takeoffs and trouble shfting smoothly from one gear to the next.

Alright, so I pulled the fuses and let it sit over night and put them back. NOW CALL ME CRAZY, call me whacky but I swear it shifts a lot better now and smoother. I feel like I actually know how to drive a standard vehicle again!

I mean this could be the placebo affect and all, but you can't tell me I all of a sudden got the manual shifting technique back. Maybe I was just having a good night. Anyway, it also seemed to idle a lot better.

I did not drive get to drive it too much, it was kinda late and I was a little tired, so I did not want to get on it too much. In other words, not sure if it feels more peppy or not right now.

If this is a placebo affect then I'm down with it!

Right now I'd say pulling the fuses was a good thing. It's shifting like BUTTA BABY!

I don't know what octane fuel my dealer put in it, but I figure 95% of them are gonna fill it with 87.

I'm happy, of course I've been happy since I got the car!

Now I just gotta get my Tire Pressure Monitoring System back. It went on the blink a few days ago and is telling me to get it serviced, BUT I'm still happy.

[Ject]

Originally Posted by irpq11

Any better?

Nope, still seems very slugish, put about 30 miles on it yesterday and still no improvement, I'll probably pull the fuses again today all day and see if it goes back to normal.

[HDDAN]

Originally Posted by jsmith

Okay so I pulled the fuses yesterday for 12 hours and had the oppurtunity to do a 0-60 run. Before the fuse pull I had a best 0-60 run of 5.2 seconds, after the fuse pull I had a run of 5.75 seconds.......... but that's becuase I was laying rubber down for 10 feet.

So I am going to try more runs and work on not lighting up the tires on my launch.

This is the kind of stuff that I love to hear. It is not raining in Boston today, so normally I would be on my Harley. But after the fuse pull the night before last and driving my re-calibrated 1SS yesterday, I couldn't resist taking the Camaro to work and doing hole shots from every light. I was leaving the traction control on and the transmission in M for sport but not tap shifting. The tires will spin for a couple of feet and then away we go! My car also never felt slow but it didn't feel 75 hp stronger than the 2002 SS that I traded in to get it. It sure does now. I made some passes at New England Dragway with my bone stock 02 SS and was turning 13.5s @ 104 mph. I plan on bringing my 2010 up there this Wednesday night to see what she will do. I will post pictures of my time slips. The only thing that will keep me from going would be rain.

[Jekyll-N-Hyde]

Do these cars show up to the dealership with close to Zero in Gas ? If so im telling my dealer to not put Gas in it . I dont want 87 octane put in and have to drive it all out and pull fuzes on a new car.

[Lord Grey]

Originally Posted by orange_5thgen

First mine is an LS3. I've been reading this thread for a few days and I figured pulling the fuses would not hurt anything. I have noticed it idling a little rough, but have not done any 0-60 times etc....

Now I've driven a few different standard/manual vehicles in my time, but I'll be damned if I have not had trouble driving this car. I figured I was just out of practice and this is not my daily driver, SO makes sense that I do not drive it every day. I've had a lot of jerky takeoffs and trouble shfting smoothly from one gear to the next.

Alright, so I pulled the fuses and let it sit over night and put them back. NOW CALL ME CRAZY, call me whacky but I swear it shifts a lot better now and smoother. I feel like I actually know how to drive a standard vehicle again!

I mean this could be the placebo affect and all, but you can't tell me I all of a sudden got the manual shifting technique back. Maybe I was just having a good night. Anyway, it also seemed to idle a lot better.

I did not drive get to drive it too much, it was kinda late and I was a little tired, so I did not want to get on it too much. In other words, not sure if it feels more peppy or not right now.

If this is a placebo affect then I'm down with it!

Right now I'd say pulling the fuses was a good thing. It's shifting like BUTTA BABY!

I don't know what octane fuel my dealer put in it, but I figure 95% of them are gonna fill it with 87.

I'm happy, of course I've been happy since I got the car!

Now I just gotta get my Tire Pressure Monitoring System back. It went on the blink a few days ago and is telling me to get it serviced, BUT I'm still happy.

I wasn't going to say anything, but I experienced exactly the same thing, regarding the shifting. I've been driving manuals for decades, but the Camaro's clutch was so different I felt like I was driving it like a beginner. After the fuse pull, I too thought the car was easier to shift. I couldn't think of a reason why the fuse pull would affect that, so I just chalked it up to me getting more used to the car.