[K12GT04]

Had the ECU replaced before the bike was ever delivered. A little after the first inspection, the bike started to show some of the signs of the bad ECU, however. Stalling on first start and touchy throttle for a minute or so. Rock steady idle, however and great throttle response. Took the bike in and the dealer (different from the selling dealer) confirmed it has the new ECU. There are no codes set. His answer - "BMWs don't even break in until 12 - 15, 000 miles, it will probably get better after you put some miles on it."

Well one, I don't think the buyer of a new 7 series would get the same answer if their new $75,000 car did the same thing, and two, I don't put a lot of miles on. It won't even be broken in by the end of warranty.

Any thoughts? Has anyone had this problem with a good ECU? Should this "clear up" after it breaks in?

Thanks

 

[Blkvelvt]

The ECU is an electronic component and does not require "break in". The bike shouldn't stall with fuel injection. Sounds like the dealer was blowing smoke where the sun don't shine. Most K-bike owners I know, push the starter button and go. No problems hot or cold start.

 

[rfespinosa]

The ECU is an electronic component and does not require "break in". The bike shouldn't stall with fuel injection. Sounds like the dealer was blowing smoke where the sun don't shine. Most K-bike owners I know, push the starter button and go. No problems hot or cold start.

I agree.

K12GT04 - the symptoms you describe are classic ECU needing replacement.

Ron

 

[lytnin]

My 04GT has a 06 or 07/04 build date on the tag. Never a problem in the summer but it does not appreciate the colder weather. It take starting it twice before it decides to stay running but after about a minute it is ready for take off without dying. I am hoping that the K-bikes are just a little cold natured and no other complaints about it.
Is that how most of the K-bikes are?

Thanks =-= Bobby

 

[dkeven]

GT start

My 04 GT has a 05/04 build date and starts first time every time. My co-worker with the Kaw Concours starts his and let it warm up while he put on helmet and gloves. I Put on hemet and gloves turn the key wait a few seconds for abs and start and push off and go. Never a stumble even down to 13 degrees. Coldest this year has been 40 so far. I would have dealer do the ECU swap on yours if they will. Or at least have them check it out. Don

 

[mikay]

I had the ECU upgraded / replaced in my '03 RS, and after doing so it ran worse.....went back to same dealer who replaced it the first time and they threw another ECU in it, was better but still not right. Went to another dealer and they discovered that the potentiometer / TPS needed to be adjusted to be compatible / in-synch with the new ECU. I would have that checked.

 

[TWB]

I had a 2002 745 and yes you do get very similar answers. The most common one was "we need to reprogram the computer". The most frustrating one was "we are waiting for new software to fix that problem".

 

[Lucky88]

Had the ECU replaced before the bike was ever delivered. A little after the first inspection, the bike started to show some of the signs of the bad ECU, however. Stalling on first start and touchy throttle for a minute or so. Rock steady idle, however and great throttle response. Took the bike in and the dealer (different from the selling dealer) confirmed it has the new ECU. There are no codes set. His answer - "BMWs don't even break in until 12 - 15, 000 miles, it will probably get better after you put some miles on it."

Well one, I don't think the buyer of a new 7 series would get the same answer if their new $75,000 car did the same thing, and two, I don't put a lot of miles on. It won't even be broken in by the end of warranty.

Any thoughts? Has anyone had this problem with a good ECU? Should this "clear up" after it breaks in?

Thanks

I know this sounds crazy, but every ECU/ control unit will perform differently. May run fine in one bike and terrible in another. Also assuming your fuel had been purchased at a reputable station, we might rule this out as a possibility of cause. Keeping in mind there are fuel changes required in different states to winterized oxygenated gasoline blend. Experiencing a cold stumble that is here now and not in the summer months could possibly be normal. Additionally the fuel and ignition mapping is different on the new ECU's. You may experience better performance in a certain RPM range and compromising in another.

Double check the work performed from the first service or any service, and make sure there were no outside influence or anything the previous mechanic left 'un-done'. Even a change in oil viscosity can make a difference in the colder weather now.

I've seen bad mechanics keep replacing control units one after another when there really isn't anything wrong with it. ( not to say you didn't get a bum ECU, which I've seen too! ). As an example, vacuum leaks, unplugged sensors, or even a lazy oxygen sensor, etc. can cause driveability issues. The ECU can only adjust so much to keep in window of optimum performance. Make the assumption of a bad ECU as a last resort, after exhausting all other possiblities.

 

[trey55]

I know that my bike would start fine and idle fine when I gave it that first hint of throttle the rpms would drop and sometimes the bike would die. New ecu and now its a start and go operation.

 

[RustyJC]

My 2003 GT supposedly had the ECU replaced under warranty by the previous owner. Despite this, it wouldn't settle into a stable idle after a cold start - I would have to work the throttle for the first minute or two to keep it from dying. I just had the 12K service performed and asked the service manager to check out the ECU to find out what the story was.

Long story short - the dealer replaced the ECU under warranty. The cold idle problem was gone. In addition, 2 other quirks disappeared - the cooling fans now cycle when they should (they never came on except after a shutdown heat soak before) and the low fuel light no longer comes on with just below a 1/2 tank showing on the gauge (the bike would take only 3.0 gallons when the low fuel light illuminated.)

Rusty

2003 K1200GT
1971 Honda CB750K1

 

[02k12rs]

I know that my bike would start fine and idle fine when I gave it that first hint of throttle the rpms would drop and sometimes the bike would die. New ecu and now its a start and go operation.

Ditto... couldn't have said it better myself, and mine is a 2002!