Educate me on twitchy throttle ECU flash

[Brian]

I bought a 15 FJ 40k miles a couple years ago. I am at the point where I want to address the on-off twitchy throttle.

I asked the second owner if he had any flash done. He said NO and didn't know if the first owner had anything done.

I went to Yamaha service today and asked if they can hook up and look at it to see if any changes were done. He looked up VIN and said there is no longer a "code 90" for my bike....think that is where Yam does fixes as a warranty. He said he would have to attach a laptop and have YAM download a PDF without knowing if he could do anything on the throttle.   

 

?? I know nothing about it and am asking what the options are.....aftermarket tuner? Taking bike to dealer?

 

EDIT: Just realized I am in GT.....let me know if I need to do a thread in FJ section.

Edited October 22, 2021 by Brian

[knyte]

This post & thread probably has all you'd be looking for:

 

[dazzler24]

Many ECU flash options out there that help greatly with the 'twitch' and also the APS adjustment which also goes a long way to taming the '15 surge.

I, and many others here, have done both and can attest to their effectiveness.

All the info you seek is within these forums.  Just use the search function and you will be rewarded. Happy hunting 🙂

 

[dazzler24]

@knyte beat me to the punch!

Brian - what knyte said.

[Skidood]

I had my ECU done just for this reason, although by 2019 Yamaha had managed to tune out a lot of the twerkiness.  One important  aspect of the flash is that the deactivation of the injectors during deceleration becomes a thing of the past.   Meaning that after the flash, (from what I understand) the injectors are still working during deceleration.   Which gives you a wee little bit of popping in the exhaust, which to me sounds great.   Yamaha deactivates the injectors on decel to keep emissions down, I believe. So generally when you are making very small adjustments  up or down to the throttle while riding, it feels more like a carbureted bike.

[bwringer]

On my '15, there were two clues that the ECU had been flashed: 

1) Some thumbfingered numbnuts broke part of the retainer. The ECU sits atop the airbox, and I did the first valve check, air filter, and spark plug change. So the only reason it would have been removed was for flashing.

2) The speedometer is pretty much dead nuts; in stock form the speedo has the usual Japanese bike optimism, but most ECU flashes correct this.

I just learned about the APS adjustment a few days ago, so I'm going to give that a try this weekend. It's hard to say for sure, but I think my bike is better than the descriptions of the stock throttle response. However, it's still not great. I'm hoping I can smooth it out with the APS adjustment.

Edited October 23, 2021 by bwringer

[texscottyd]

Hi @Brian- The abrupt on/off-throttle response was fairly pronounced on the early FJs, which makes them prime candidates for an ECU reflash.   I had mine done by Two Wheel Dynoworks (https://2wheeldynoworks.com/) and combined with the APS adjustment described above, I’m really pleased with the results.  I still have the stock exhaust on my 2015 FJ, but they have appropriate fuel maps for both stock and aftermarket pipes.   There are several other vendors that offer similar ECU flashing services.   

Two clues that yours has already been done: 

- Does it start in STD Mode or A Mode?   The stock bikes default to STD, but almost everyone elects to have it default to A Mode with a reflash.  

- Does it have a speed governor at 114 mph?  The U.S. spec FJs were factory limited to 114 mph indicated, which it will do in 3rd, 4th, 5th, and 6th gears.  If yours will pull past that, it has definitely been reflashed to remove the electronic speed governor.   How you choose to test this is 100% up to you… 😉

I hope this helps.  The ECU reflash and APS adjustment is a nice improvement on the early bikes, and I think you would be happy with the results.  

-Scott 

[wanderer]

3 hours ago, texscottyd said:

 Does it have a speed governor at 114 mph? 

Should be fun to test it out!

[CRFan250]

Get your ECU flashed by Ivan's Performance and enjoy a whole new bike, haha.

[piotrek]

There is another option that works surprisingly well, and doesn't require a flash. You can read about it here.

The flash does a bunch of good things that the O2 controller won't, but I thought I would just close the loop a bit on the options to address the twitchy throttle issue specifically... if that's all you're after. This mod should be under 1/3 the cost of a flash... if you can still find it in the ether somewhere.

[Wintersdark]

8 hours ago, piotrek said:

There is another option that works surprisingly well, and doesn't require a flash. You can read about it here.

The flash does a bunch of good things that the O2 controller won't, but I thought I would just close the loop a bit on the options to address the twitchy throttle issue specifically... if that's all you're after. This mod should be under 1/3 the cost of a flash... if you can still find it in the ether somewhere.

The Booster Plug achieves this as well with a very creative method - it enrichens the air-fuel mixture by making the ECU think it's 20C cooler than it actually is.

I ran mine for about a year and it was spectacularly successful, but it's been pulled pending a new exhaust and flash.  

Its a damn good piece of hardware, but only corrects the low rpm fueling and does nothing else.

If anyone is interested, shoot me a DM - I'd pass it on for $50.  

[BBB]

On 10/23/2021 at 12:47 AM, Skidood said:

I had my ECU done just for this reason, although by 2019 Yamaha had managed to tune out a lot of the twerkiness.  One important  aspect of the flash is that the deactivation of the injectors during deceleration becomes a thing of the past.   Meaning that after the flash, (from what I understand) the injectors are still working during deceleration.   Which gives you a wee little bit of popping in the exhaust, which to me sounds great.   Yamaha deactivates the injectors on decel to keep emissions down, I believe. So generally when you are making very small adjustments  up or down to the throttle while riding, it feels more like a carbureted bike.

I didn't think that was the reason for the decel pops (but could be wrong of course). I thought it was the AIS (air injection system) which is switched off in the flash, so there is no air mixed in on deceleration and so you get a richer mixture going through the hot exhaust.

[Skidood]

2 hours ago, BBB said:

I didn't think that was the reason for the decel pops (but could be wrong of course). I thought it was the AIS (air injection system) which is switched off in the flash, so there is no air mixed in on deceleration and so you get a richer mixture going through the hot exhaust.

I think you could be right.  Here is a list of changes that were done on my flash.  I told the guy I am using the OEM exhaust. 

 

Edited October 24, 2021 by Skidood
.

[Clicknow]

Another clue is what temperature the fan kicks in mine has had a flash and fan comes on at 95 degrees 

regards 

[Brentinpdx]

I have recently purchased a 2015 FJ09 with 3800 miles.  I have read a lot about the re -flashing the ECU. Which flash tuner are ones to stay away from?