Fuse pull highly recommended

[PQ]

Originally Posted by camarohwk23

Now I'm confused. I was going to do a fuse pull but I had my battery disconnected when I was installing my CAI. I felt a difference in power and torque and I assumed it was because the CAI. Now I'm wondering if it could have been from the fuel map being reset also. I will say this, there was a huge difference, especially in throttle response.

If it's throttle response I'd guess you are feeling the intake.

On the SSs there is a battery back-up so it doesn't reset the ecu. I dynoed mine originally before I figured out the fuse pull problem and the battery disconect did nothing. And I had the battery out over night.

[mlee]

Originally Posted by Al C.

Will this get the same results as a fuse pull?

Originally Posted by Al C.

See post #41

I'm pretty sure it will, but it's way easier to pull the fuses.

[rpepka]

It was really bad when it happened. Took my car to the dealer 4 times and they would not listen! I got tired of messing with it sold it and bought another.

[Deke736]

Originally Posted by rpepka

It was really bad when it happened. Took my car to the dealer 4 times and they would not listen! I got tired of messing with it sold it and bought another.

What?

[OldJedi]

Just out of curiosity, when you pull the fuses (5 & 20) and let it sit overnight, how will the system "reset" itself overnight by itself without any power? Just not sure how this whole idea works with the engine off and no power going through the fuse panel. Thanks.

[Al C.]

Originally Posted by OldJedi

Just out of curiosity, when you pull the fuses (5 & 20) and let it sit overnight, how will the system "reset" itself overnight by itself without any power? Just not sure how this whole idea works with the engine off and no power going through the fuse panel. Thanks.

I think that's why fbodfather said to disconnect the battery....just another option..

[hairtrigger]

Originally Posted by OldJedi

Just out of curiosity, when you pull the fuses (5 & 20) and let it sit overnight, how will the system "reset" itself overnight by itself without any power? Just not sure how this whole idea works with the engine off and no power going through the fuse panel. Thanks.

When it "has" power it will keep looking at the low octane fuel map which was sensed by the detonation induced 87 you ran.
Disconnect the power and it will reboot and default to the high octane fuel map again when power is reconnected.
It is all about ignition timing and detonation.
Apparently the ECM cannot relearn to a higher octane after you wreck it with a detonation prone 87 octane.
So fuse pull to reset and run the highest octane you can get locally.

[hapisok]

Originally Posted by Al C.

I think that's why fbodfather said to disconnect the battery....just another option..

has to do with electronics and "latching". when a lower octane is recognized, it switches to the lower table and is latched to that setting through electronic signals... 1 & 0's. pulling the fuse removes or disengages the latch and tells it to go back to the default higher octane table where it will stay until it recognizes low octane and you'll have to go through the process again.

the reason it might require being pulled for a period of time (overnight) vs pulling and putting it right back in, is to allow for the discharge of the voltage within the circuit that is creating the latch. similar to how a capacitor will hold a voltage once removed from a circuit until discharged, but can also lose its charge over time.

[2cnd chance]

Anyone else experience positive results?

[joes407]

what if you buy gas at a station that has 1 hose for all the fuel grades? if the guy before you buys regular do you get a hosefull of regular before your premium?

[strych9]

LOL @ "reboot". Well, kind of.

The ECM fuel tables have "volatile" memory, meaning that if power is taken away from that memory, the data within it is lost. Fuse 5 and 20 have power through them at all times, to keep the memory alive. When you pull those fuses, the memory erases. When you re-install and then start the engine, the ECM looks at the new values since there are none stored in memory, and stores the new information, which is retained until the next fuse pull, OR you run lower octane fuel and if needs to move to the lower octane data table.

[OldJedi]

Originally Posted by strych9

LOL @ "reboot". Well, kind of.

The ECM fuel tables have "volatile" memory, meaning that if power is taken away from that memory, the data within it is lost. Fuse 5 and 20 have power through them at all times, to keep the memory alive. When you pull those fuses, the memory erases. When you re-install and then start the engine, the ECM looks at the new values since there are none stored in memory, and stores the new information, which is retained until the next fuse pull, OR you run lower octane fuel and if needs to move to the lower octane data table.

OK thanks, now I understand better. I did not realize that there was constant voltage going through fuses 5 & 20. I thought the fuses would only be active when the ignition was on. I appreciate the information.

[Z Boss]

I'll echo the others with an attaboy to those of you who are smart enough to figure this out and take the time to post the info! Thank you!! The ZL1 tech at my dealership did not know this either.

[Hercules]

Originally Posted by joes407

what if you buy gas at a station that has 1 hose for all the fuel grades? if the guy before you buys regular do you get a hosefull of regular before your premium?

Great question, I worked at a gas station and always wondered that. I don't see how you don't get a hose full of the previous persons grade of fuel. It's got to be sitting there.