I have been chasing an issue for a while. I originally thought it was in the tuning but now I think it is something else. I have swapped tuners, maps and even had the bike dynoed several times.


The issue I have is way more pronounced if I am in auto tune (Target tune).


If I am on the gas relatively hard and roll off the throttle around 3K RPMS the bike starts bucking, surging and popping. It will stop doing it if I get off the throttle and back on or if I go WOT and then back off.
This is about the same area I get what I think is pinging at steady throttle. (Sounds like rocks hitting the tank).
Out of auto tune I do not have the surging or popping but I do hear the pinging sound.


I am starting to think I may have a signal issue between the throttle and the throttle body. The signal may be causing all of the running issues and could be the cause of the pinging. I am sue there is a way to meter it for resistance but honestly I have no idea how.


I am looking for ideas here because I have spent a ton of money and time chasing this. All connections are clean and dielectric greased.


The issue did not start after any king of mods, just began happening one day. While chasing the issue I have swapped the bars again.

 

oh man, sorry you are still fighting this- I see your other thread about smelling exhaust- related?

the throttle grip is used to open a valve in the throttle body to allow air in- either with a TBW or a cable.

i don;t think a fault there could result in the kinda of trouble you are having when revs are dropping from WOT..what you will have is high engine vacuum and the sensors should be triggering the ECM to alter the spark timing and fuel delivery.

I know you've been having a variety of problems- quick question are you sure there are no intake leaks and that the cap is on the unused intake hose barb?

Mike

 

I was havinga similar issue on my SG 2011,I'd be cruising at 70 mph at 2700 or so rpm and once I twisted the throttle up to 3000 it would hesitate and stutter.
Once passed the 3000 rpm and at around 85 it ran well,chased that issue for a long time.
Replaced filter,regulator,checked plugs,wires, changed tunes from Fuelmoto's map to original and back the the FM map.....nada!
Decided on one more part to replace before heading out to the dealer, order the Twist Grip Sensor.
It's running very well now,gonna go and run some autotunes as I tweaked the original thinking it was that....

 

I had something like that happening with my 06 Ultra some years back, did some data logging and found it going nuts with knock retard. After some fiddling around chasing things I ended up swapping the plug wires when I found the old wires out of spec. Problem was solved and never returned.

 

I don't think the exhaust and this are related. I am thinking the exhaust smell is simply creating a vaccume at the rear of the bike. Kind of like some cars the rear is always dirty. Come to think of it the back of my bags are always dirty.


I have checked and replaced the intake gaskets. The plug is on tight. I do not think it is an intake leak. I have swapped the plug wires (just to make sure) I am leaning towards the Fly by wire twist throttle going bonkers. When I check codes I get a loss of tach signal code. According to the guy at Fuel Moto (Not Jamie) that is common. I know the twist throttle is in essence a resistor based on throttle position. I just wonder if it cannot ramp up or down fast enough to compensate for the change in position. The sputtering occurs in auto tune but not in regular mode. I wonder if it is trying to compensate but a temporary loss of signal.

 

whats the number of the code?

the throttle is 2 potentiometers ( like a volume ****) which work opposite of each other...so if one says I'm at 68%, the other will say I'm at 32% ( or an even better analogy, more like the balance **** on the hifi ) ...they always add up to a value of 5 volts ( or 100%) to the ECM ( and there are better explanations on the web if this isn;t clear).
If there is a fault ( which would be any reading outside of a 5 volt "100%", the ECM will store a code.

I'm wondering of you are noticing the exhaust because the motor isn't burning everything clean ( for which ever reason) a good running motor won;t have much of a smell to it- if you are smelling raw gas, then there is too much fuel or a misfire.
I got all kinds of cars and bikes, new and old- the new stuff burns so much better/ cleaner than the stuff 40, 50, 60 years old

that code could be the key- I know you've been fighting problems with driveability but don;t recall the exact problems, when the occurred and what changes have been made- before/during/after

mike

 

shoot,, I was hoping he would give you (mk) a code.
kroozeabout.

 

Thank you for the explanation on the throttle. That is a very understandable explanation. The exhaust is not necessarily raw fuel but just kind of strong smelling. When I went out to pull the codes from the bike I was looking it over and the back of the bags are nasty (dust road grime) while the rest of the bike is pretty clean. I am with you if the bike is running at it's best the smell should be minimal, if at all. I may get some because my pipes are covered most of the bay by bags and fender, which causes a vacuum area behind bike.






PV stored code says:


Tachometer:U1 6 HIST
Loss of ICM/ECM Serial Data Instruments.




Like I posted before the guy at Fuel Moto didn't seem to be concerned with the loss of tach signal. I get the soft code every time I check the codes.

 

bump this up, with the code info.

I don;t use dynojet products- but a loss of serial data can;t be a good thing-

it can indicate a loss of reference voltage ( 5 volts) to the sensors, or a lack of data returning to the ecm...somewhere in there at some point the computer doesn;t know how fast the bike is going or how fast the motor is turning.

mike

 

I agree. My next step, once the weather clears up some, is to put it in Auto tune and do some data logging. Once I have that I'm going to give Jamie a call. To see if the log will give us a clue as to what is going on.