Gas attendant put 87 octane in my car (LS3)

[pickwithaustin]

Your car's computer will adjust to the lower octane and change your timing. Personally, I would not siphon it out, just fill it with premium as you go, then do the fuse pull trick to get her back in sync.

I haven't seen gas station attendants for nearly 30 years now.

Do they still give free oven mits??

[Spec]

Originally Posted by Daxal84

Pulled the fuses to be safe. I'm gonna try to siphon most of it out tomorrow. Thanks for all the help. Knew I could count on all of you.

You should wait on pulling the fuses until after you've removed all the 87 octane from your ride. Sorry I didn't mention that... here's more info;

There are two specific spark timing tables housed in the memory of the vehicle’s Electronic Control Module (ECM). One is used for cars running high octane fuel and the other for when the vehicle is using low octane fuels. Whenever you drive the vehicle, the ECM is constantly making decisions based on the data it receives from all of the sensors in the engine and exhaust. Over time, the ECM will set your Long Term Fuel Trim (LTFT) to the low octane tables.

The problem:

If someone puts a low octane fuel into the tank, the vehicle can’t recover from the low octane table. Once in the low octane table the car will continue to use that information even if you are now using a higher octane fuel. Of course the side effect of this is sluggish performance, and we don’t really need to explain the benefits of running a higher octane fuel in a performance application. If you just purchased your Camaro you wouldn’t be incorrect in thinking that it isn’t uncommon that at some point the car was filled with a less potent gasoline, especially if it came from a used car dealership or from an owner who was uninformed of this problem and wanted to save a few bucks at the pump. The LTFT’s are, unfortunately, a part of the car’s non-volatile memory. That means the information is stored there, and doesn’t reset when the vehicle is turned off.

However, there is a way around this problem. Although the spark tables are part of the non-volatile memory and cannot be removed, they can be reset. A simple solution is to remove a couple of fuses from the fuse block in the engine compartment. Pulling the fuses will allow your Camaro’s ECM to reset itself to the high octane table. If you are running high octane fuel then it remain in the high table until the ECM again detects a low octane fuel.

The fix:

First, make sure the car is empty of the low octane fuel. Run the tank down low and refuel with high octane. You might consider running a tank or two through before attempting the fuse pull. Once you have better gasoline in the system, locate the two fuses shown in the diagram below. They are in the fuse box located on the passenger side of the vehicle’s engine bay. The fuses are in position #5 and #20. Remove each of these 15 amp fuses and allow the car to sit for a period of at least a few hours. There is a small, grey fuse pulling tool located on the fuse panel (In the diagram below it would be in the lower right corner area). That should make the pulling of the fuses easier. If possible, remove the fuses and allow the car to sit overnight. Once they have been out for several hours, replace the fuses. When started, the car will attempt to use the high octane fuel trims first, and if you keep high octane fuel in the car it should remain on the higher table permanently. Of course, lowered octane fuel in the tank means repeating the process.

http://www.camaro5.com/forums/showthread.php?t=230502

[Daxal84]

No free mits....just the wrong gas...

[Daxal84]

Originally Posted by Spec

You should wait on pulling the fuses until after you've removed all the 87 octane from your ride. Sorry I didn't mention that... here's more info;

There are two specific spark timing tables housed in the memory of the vehicle’s Electronic Control Module (ECM). One is used for cars running high octane fuel and the other for when the vehicle is using low octane fuels. Whenever you drive the vehicle, the ECM is constantly making decisions based on the data it receives from all of the sensors in the engine and exhaust. Over time, the ECM will set your Long Term Fuel Trim (LTFT) to the low octane tables.

The problem:

If someone puts a low octane fuel into the tank, the vehicle can’t recover from the low octane table. Once in the low octane table the car will continue to use that information even if you are now using a higher octane fuel. Of course the side effect of this is sluggish performance, and we don’t really need to explain the benefits of running a higher octane fuel in a performance application. If you just purchased your Camaro you wouldn’t be incorrect in thinking that it isn’t uncommon that at some point the car was filled with a less potent gasoline, especially if it came from a used car dealership or from an owner who was uninformed of this problem and wanted to save a few bucks at the pump. The LTFT’s are, unfortunately, a part of the car’s non-volatile memory. That means the information is stored there, and doesn’t reset when the vehicle is turned off.

However, there is a way around this problem. Although the spark tables are part of the non-volatile memory and cannot be removed, they can be reset. A simple solution is to remove a couple of fuses from the fuse block in the engine compartment. Pulling the fuses will allow your Camaro’s ECM to reset itself to the high octane table. If you are running high octane fuel then it remain in the high table until the ECM again detects a low octane fuel.

The fix:

First, make sure the car is empty of the low octane fuel. Run the tank down low and refuel with high octane. You might consider running a tank or two through before attempting the fuse pull. Once you have better gasoline in the system, locate the two fuses shown in the diagram below. They are in the fuse box located on the passenger side of the vehicle’s engine bay. The fuses are in position #5 and #20. Remove each of these 15 amp fuses and allow the car to sit for a period of at least a few hours. There is a small, grey fuse pulling tool located on the fuse panel (In the diagram below it would be in the lower right corner area). That should make the pulling of the fuses easier. If possible, remove the fuses and allow the car to sit overnight. Once they have been out for several hours, replace the fuses. When started, the car will attempt to use the high octane fuel trims first, and if you keep high octane fuel in the car it should remain on the higher table permanently. Of course, lowered octane fuel in the tank means repeating the process.

http://www.camaro5.com/forums/showthread.php?t=230502

oh man already pulled them. I'll go put them back in now. This is great information. appreciate it.

[Spec]

Originally Posted by Daxal84

oh man already pulled them. I'll go put them back in now. This is great information. appreciate it.

No prob... I'm making it a habit of pulling the fuses every time I get an oil change.

[Red Jewel RS]

Running low octane in our cars is not like some have mistaken and put diesel fuel in a gas engine. Like it was said above, GM designed these engines to run on 87. That's not the "recommended" octane but the computer will adjust to it. Your performance will suffer temporarily until you change octane.
I had a bad tank of gas in mine a while ago and I could hear the knock when I put my foot in it, so I just drove it easy until I emptied the tank, changed gas stations and pulled fuses.

[forespeed]

When I purchased my 2013 ZL-1 it had 37 miles on it from the dealers owner testing it I guess.
I didn't know anything about the low octane usage but I put 93 in at every fill up. After several months of disappointing performance I had the car dyno'd in preparation for an upgrade and tune. The results of the Dyno showed the car down about 45hp at the rear wheels. The upgrade I had done was advertised as a plus 50hp. The actual results were a plus 91hp at the rear wheels.
I never heard of the fuse pull so it took a tune to change the car back and the tuner ask if I wanted 87,91 or 93 set in the ECM and I chose 93.

[JCunningham]

if your not tuned you will be fine just baby it. run 2 tanks of 93 through it and pull the fuses. the car stock can detune itself to run on 87. I sure would not have paid for the gas.
We need a fuel cap sticker that says 93 octane or higher only

[Destructo09]

It'll be fine, I wouldn't even bother siphoning it out. After you run the tank out and refill with 91/93 then do the fuse pull.

My motorcycle makes 150HP on a 1.0L engine, like somebody else said it runs on 87 octane. However the other person didn't bother to bring up dynamic compression, this is what truly makes the difference on fuel octane. The cams in my 150HP 1.0L engine have so much overlap that it must idle at over 1k rpm and this causes the dynamic compression to be low enough that 87 octane is just fine.

Bottom line, 87 octane won't hurt a stock non-tuned LS3, if it could then lots of folks with brand new SS Camaros would be in trouble lol. The owners manual even states that regular fuel is ok, but 93 is recommended.

[Daxal84]

Thanks for everyone helps. I'll really have to put the miles on it then to get through a few tanks of gas. I'm dropping the car off on July 31st for some engine work.

[Badfinger]

Just put some octane boost it and drive it.....

[dantemcc]

You cant pump your own gas? Is this some kind of sick twisted joke? LoL. No way on God's green earth would I ever let anyone put something in my car and if I had to, I'd be out there watching eveythey did. Sorry man for the travesty. Put the stations name in the newspaper or on your local news. Let everyone know what they did to your car and how you should get free 93 octane gas FOR LIFE! I'm only kidding. Slightly.

[SuperSport2011]

Just take a deep breath and you'll be okay. As long as you're not constantly at wide open throttle you'll be okay and even then you're fine.

[flyer08]

Run it out, refill with 94 twice, pull fuses to reset fuel trims, you'll be ok