Join Date: Jul 2006
Location: Minneapolis, MN, US
You're probably right. Any injected motor gets a richer fuel mix when cold. The electronic fuel management system measures the inlet air temp, motor temp, O2 in the exhaust, and usually a few other things like engine knock. The fuel mixture gets adjusted to keep the motor running smoothly at low temps. The amount of enrichment is dictated by the "map" in the software.
The bucking/sharp throttle response folks are getting with the early software is an overly lean (yah, yah grammar) profile trying to keep low rpm exhaust emmisions legal. Most motors don't struggle so much, but with a compression ration of 13:1 our bikes are special.
In cold weather most motors eventually warm up and fuel metering goes to a nice lean mix. The 6 liter V8 in my pickup is hidden behind a radiator, hood, and fenders. It takes about 30 minutes to lean up. It's possible that at 35 degrees there is enough air flowing in and around the GT's motor that it never does make it to the full lean of summer, resulting in a richer idle friendly mix all the time.
I suspect the high idle issue is an improper response to a certain set of sensor inputs. I can get it to happen on the way home from work on warm days. 45 min. at highway speeds followed by a 1 min. 120+ dash, followed by an offramp and a stoplight. O2 sensor probably gets loaded by the short duration full throttle position, causing the system to want to lean up. This ends up being too lean, so the computer reacts and richens up. See a confict? Probably causes the software to switch to a limp home mode. Turn bike off, reset computer, drive a way.
I'm getting the 7 upgrade. I know a guy that had the same problems with his R, 7 fixed it.