2000 RPM idle???

[busanuts]

Hi, I have a 2005 stock Limited edition busa. At startup it idles around 800RPMs but when it reaches normal operating temperatures it starts to idle at 2000RPMs. Now mind you everything is stock, I tired backing off the idle screw but it has already reached its limit. What do you guys think it is?

[Tybalt]

yes 2000 is to high and 800 is to low, the busa is complete stock?, no TRE? if you have a TRE take it off and see? the Busa @ idle should be like 1200 rpm range

[cb2004mj]

sometimes if you live in a hotter climate it will idle high for a few minutes when its at temp. and then fall back down to stock idle after sitting there a bit, which should be 1100-1250 i beleive. try taking it out and once its at temp let it sit and idle at the 2k and see if it falls back down to the 800 after a few minutes. if so your fine. mine does it all the time but its 95 outside all the time here too. you still need to get ur rpm at 11-12 tho so tune it back up a little.

[busanuts]

yes 2000 is to high and 800 is to low, the busa is complete stock?, no TRE? if you have a TRE take it off and see? the Busa @ idle should be like 1200 rpm range


Yes the busa is completely stock and there is no TRE. I agree that it should idle around 1000 and 1200. Thanks for prompt response guys.

[busanuts]

sometimes if you live in a hotter climate it will idle high for a few minutes when its at temp. and then fall back down to stock idle after sitting there a bit, which should be 1100-1250 i beleive. try taking it out and once its at temp let it sit and idle at the 2k and see if it falls back down to the 800 after a few minutes. if so your fine. mine does it all the time but its 95 outside all the time here too. you still need to get ur rpm at 11-12 tho so tune it back up a little.

I live in Brooklyn, NY and temperatures vary but since I only use it during the summer season, yes it is hot out here. The busa idles around 800 when I first start it and after 15 to 30 minutes of riding the idle cranks to 2000 and will stay there. Dont know what it could be and im sure it is something stupid. Anyway guys thank you all for your help. If you have any more ideas on what can be causing this high idle let me know.

[Tybalt]

I live in Brooklyn, NY and temperatures vary but since I only use it during the summer season, yes it is hot out here. The busa idles around 800 when I first start it and after 15 to 30 minutes of riding the idle cranks to 2000 and will stay there. Dont know what it could be and im sure it is something stupid. Anyway guys thank you all for your help. If you have any more ideas on what can be causing this high idle let me know.

Ok, my guess it is a sensor like the AIR PREASURE SENSOR or AIR TEMPERATURE SENSOR (the green one located snapped in to your air box) you need to put the busa into self diagnostic mode and retrieve the C CODE # on the dash????? error code and we can diagnose it

http://www.busanation.com/forum/showthread.php?t=148

[cb2004mj]

good stuff chief, i knew we kept ya around for something :) lol

[busanuts]

Ok, my guess it is a sensor like the AIR PREASURE SENSOR or AIR TEMPERATURE SENSOR (the green one located snapped in to your air box) you need to put the busa into self diagnostic mode and retrieve the C CODE # on the dash????? error code and we can diagnose it

http://www.busanation.com/forum/showthread.php?t=148



Awesome, I will try that and report back with a code. For the dealer mode switch all I have to do is short the two wires with a paper clip? Please let me know.

[Tybalt]

Awesome, I will try that and report back with a code. For the dealer mode switch all I have to do is short the two wires with a paper clip? Please let me know.

Yes, white connector located under left side passenger seat, loop a paper clip, busa in neutral, engine kill switch OFF, turn key on

[busanuts]

Yes, white connector located under left side passenger seat, loop a paper clip, busa in neutral, engine kill switch OFF, turn key on


Ok, I have put the system in dealer mode by looping a paper clip in the white modular plug underneathe the passenger seat and the following are my results. I get a -C00 as my code and that means that nothing is mulfunctioning. However, I know that 2000rpm is too high for an idle. SO at this point I just dont know what it is. Let me know if you guys get anymore idaes. Thanks to you all.

[NINJA KILLER]

Have someone check your Throttle Position Sensor .:smoke:

[busanuts]

Have someone check your Throttle Position Sensor .:smoke:


Yeah good idea. I may have to that casue I hate when I coast to a traffic light and my idle is at 2000rpms It feels like im on a 2 stroke engine.

[Quasar]

Hayabusa engines idle best at 1,200 to 1,250 RPM.

Of course, the problem is, you cannot get it to run any lower than 2,000 RPM once the engine has warmed up.

Typically, when you've reduced the idle screw to its lowest position and it's still idling way too high, "Throttle Body Synchronization" is the likely culprit. One of the traits is a wide swing in idle RPM as you've stated (from 800 to 2,000 RPM).

The fact that it can idle as low as 800 RPM tells you that it is HIGHLY unlikely that it's a cam-related issue (as in incorrect cam timing). Incorrect cam timing makes it very difficult for the engine to idle at low RPM smoothly enough to stay running.

The other culprit is a Throttle Position Sensor that is changing its resistance as it heats up. The higher the resistance, the more fuel provided by the ECM however, all the fuel in the world can be fed to closed throttle butterflies and the engine can increase its RPM only so much prior to becoming overly rich and slowing the idle RPM. This is why it sounds more like throttle body synchronization is required. If one or more throttle bodies are getting sufficient air intake, then the engine's idle RPM can be jacked up by fueling.

I'd check the throttle body synchronization and adjust as necessary.

[busanuts]

Hayabusa engines idle best at 1,200 to 1,250 RPM.

Of course, the problem is, you cannot get it to run any lower than 2,000 RPM once the engine has warmed up.

Typically, when you've reduced the idle screw to its lowest position and it's still idling way too high, "Throttle Body Synchronization" is the likely culprit. One of the traits is a wide swing in idle RPM as you've stated (from 800 to 2,000 RPM).

The fact that it can idle as low as 800 RPM tells you that it is HIGHLY unlikely that it's a cam-related issue (as in incorrect cam timing). Incorrect cam timing makes it very difficult for the engine to idle at low RPM smoothly enough to stay running.

The other culprit is a Throttle Position Sensor that is changing its resistance as it heats up. The higher the resistance, the more fuel provided by the ECM however, all the fuel in the world can be fed to closed throttle butterflies and the engine can increase its RPM only so much prior to becoming overly rich and slowing the idle RPM. This is why it sounds more like throttle body synchronization is required. If one or more throttle bodies are getting sufficient air intake, then the engine's idle RPM can be jacked up by fueling.

I'd check the throttle body synchronization and adjust as necessary.


That is a great explanation on what could possibly be happening and will work on getting the Throttle Body Sync checked and adjusted if neede. Thanks for your help. I will check in soon with answers!!!! Thanks again all.

[BRKNWNG]

Ok, I have put the system in dealer mode by looping a paper clip in the white modular plug underneathe the passenger seat and the following are my results. I get a -C00 as my code and that means that nothing is mulfunctioning. However, I know that 2000rpm is too high for an idle. SO at this point I just dont know what it is. Let me know if you guys get anymore idaes. Thanks to you all.

Sounds like it may have a vacuum leak.

[240kanji]

duuuuuuuude i was havin the same problem. it was driving me nuts. pull it out the garage and im idle'n fine. thennnnnnnn 20 minutes up the road come to a red light and im sittin at 2 grand. drove me nuts for like 2 weeks. then i yanked off my TRE and it stopped. i lost alotttttt of power but i'd rather be idle'n normal then sittin at a light and sounding like im a staging at a drag tree hahahaha

[Tybalt]

duuuuuuuude i was havin the same problem. it was driving me nuts. pull it out the garage and im idle'n fine. thennnnnnnn 20 minutes up the road come to a red light and im sittin at 2 grand. drove me nuts for like 2 weeks. then i yanked off my TRE and it stopped. i lost alotttttt of power but i'd rather be idle'n normal then sittin at a light and sounding like im a staging at a drag tree hahahaha

:cheers: welcome, txs good to know

[Quasar]

duuuuuuuude i was havin the same problem. it was driving me nuts. pull it out the garage and im idle'n fine. thennnnnnnn 20 minutes up the road come to a red light and im sittin at 2 grand. drove me nuts for like 2 weeks. then i yanked off my TRE and it stopped. i lost alotttttt of power but i'd rather be idle'n normal then sittin at a light and sounding like im a staging at a drag tree hahahaha

Pulling the TRE didn't resolve the actual issue though it did satisfy your most immediate need to keep the idle RPM from running high, as you went right back to your OEM retarded ignition timing by pulling the TRE.

It wasn't the TRE that was causing your issue however, if it were, EVERYONE who ever installed a TRE would be experiencing the very same issue because the TRE invokes the identical ignition timing and fueling of 5th gear. This is a typical case where the TRE takes the wrap for another underlying issue that was never diagnosed and resolved. If you ever resolve your actual issue, you'll be able to reinstall the TRE and gain your extra low-end grunt as well as idle reliably. I've been using a TRE for the past 8 years or so now and I don't experience any runaway idle issues.