fuse pull

[kstroik]

I see on some threads their is talk about pulling two fuses if your going to run 91, or 93 octane. Can someone enlighten me about this please.

[caliguy]

yes for SS's pull 5 & 20 fuse let it sit over night, and don't run 88 octane again, if you do then you'll have to repeat process when you put in 91-93 octane, so stick with high octane for now.

[kstroik]

what is the advantage doing this. car run better? more power? or just better for the car?

[The Stig]

Originally Posted by kstroik

what is the advantage doing this. car run better? more power? or just better for the car?

All of the above

[caliguy]

Pull the fuse's tonight and in morning put back in, fire up take a drive you'll notice it

Originally Posted by kstroik

what is the advantage doing this. car run better? more power? or just better for the car?

[kstroik]

thanks for the help.

[1sicss]

did mine, definitly makes a difference

[Apex Motorsports]

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.

[StOrM TrOOpEr]

if u have a tune.. would this get affected if u do a fuse pull?

[invaderzim]

what's the purpose behind the hours? is it like a security feature the car has so in case the fuses momentarily pop out while sitting in your garage it doesn't reset anything? so they have to be out a few hours to reset the system.. seriously though, this part I never understood. can someone explain?

[SSBlack]

The time has to do with allowing the ECM to fully reset, discharge, you could say.

And, it does matter. One or two hours gave me no results. Overnight, it was back to the Camaro I know and love.

I bought a tank of what I thought was 93. No way it was. Car was sluggish.

You know that neck jerking acceleration? It became bogged down.

I contacted that station. They claimed that they tested it and it tested to be 95? 95?

Watch where you buy gas. And, one more time, GM. Is a fuse pull going to be the ONLY resolution to this?

[AirManFL]

It's a sticky in the bolt ons section.

Tons of info:
http://www.camaro5.com/forums/showthread.php?t=38964

Rob

[One-Bad-ZL1]

You electrical engineers can back me up on this, but I believe it take the capacitors in the ECM awhile to completely discharge allowing those key circuits controlling table acquistion to reset. After all, I did sleep at a Motel 6 last night.

[The Stig]

Originally Posted by StOrM TrOOpEr

if u have a tune.. would this get affected if u do a fuse pull?

no. Your tune will not be harmed by doing a fuse pull.