08 CBR1000RR rough idle - Honda CBR1000 Forum : 1000RR.net
 
Thread Tools
post #1 of 5 Old 08-16-2019, 12:12 PM Thread Starter
dgram
Junior Member
 
Join Date: Dec 2013
Posts: 3
08 CBR1000RR rough idle

Hey guys - I've got a 08 CBR1000RR that I barely ride. It's got a full yoshi with pc3. It has a bit of a rough idle while it's cold and when it gets up to temp. Checked the mapping to ensure it was still current with what dynojet has it was all good to go. I did notice that where the throttle position reading was on the screen it showed 100 instead of 0. Any information would be greatly appreciated. Thanks!!
dgram is offline  
Sponsored Links
Advertisement
 
post #2 of 5 Old 08-16-2019, 12:40 PM
09_Blade
Member
 
Join Date: Oct 2018
Posts: 66
Last year, I spent 7 months trying to fix this issue on my '09 with a R77. This is a very well documented issue on 08-11 bikes. Here's a breakdown of everything I've learned through trial and error.

On a 2012+, it is possible to achieve a smooth idle at 1200rpm with fuel and ignition timing adjustments. From my understanding, it is because Honda increased the flywheel mass to "improve low end stability."

On a 2008-2011, no AFR or ignition timing adjustments will fix the issue, nor will balancing the idle manifold vacuum for all four cylinders (painstaking!)

I installed a PCV w/ auto-tune and tried every AFR from 10-15 and the rough idle still persists once the IACV hones in on 1200rpm. I adjusted the ignition timing through the ECU, verified with a timing light from 0-15 degrees of advance. Even tried adjusting the timing and fuel "around" the idle region to nudge it back to 1200rpm. Still no improvement.

Also did a valve adjustment and cleaned out the intake valves with no change to idle quality.

Oddly enough, partially covering the exhaust or inserting the baffle fixes the idle instantly, but I could not stand the pathetic scooter sound.

I began bumping up the idle from 1200rpm through the ECU. I found that an idle target of 1400rpm fixed the loping completely and does not overheat in 100+ degree Texas weather. 1300rpm shows huge improvement, but still lopes a little bit.

Good luck!
09_Blade is offline  
post #3 of 5 Old 08-16-2019, 02:30 PM Thread Starter
dgram
Junior Member
 
Join Date: Dec 2013
Posts: 3
Ahhh I see. if I Rev it up and hold it at about 4k rpm it still lopes a bit. Is that normal as well?
dgram is offline  
post #4 of 5 Old 08-16-2019, 03:18 PM
09_Blade
Member
 
Join Date: Oct 2018
Posts: 66
No. That is not normal. The loping goes away when you get to 1500+

That sounds like a manifold vacuum leak on one of the cylinders or a fuel injector connection issue or a mis-calibrated TPS.

You need to first figure out whether it's the PC or not. Open up the Dynojet software and select the calibration option. You will start with throttle closed then open it all the way after you start.

The Yoshi exhaust does not cause any problems above 1500rpm. If the PC isn't to blame, it's time to check the hoses.

There are two vacuum hoses coming off cylinder 1 and one vacuum hose coming off cylinder 2, 3, and 4. The first vacuum hose goes to the flapper system. Did you remove the flappers and forget to plug the hose? One hose from each cylinder goes to a 5-way connector that hooks up to the MAP sensor. Check those since it's easy to unplug when you are messing with the fuel injector connectors.

If you bike is a California model, there is another set of four hoses going to the charcoal canister purge valve... which is another common source of vacuum leaks.

With a vacuum gauge, measure the manifold vacuum. It should be about 22cmHg for all four cylinders.
09_Blade is offline  
post #5 of 5 Old 08-16-2019, 06:15 PM Thread Starter
dgram
Junior Member
 
Join Date: Dec 2013
Posts: 3
I started with the TPS reset. It read that it was at WOT while idling lol. It's back to normal now after the reset.

Flappers inside the intake tubes?

If so, I did take the mid fairing off this summer and removed vacuum hoses from it. I put them bsck on in the same order I took them off but the rubber cap on the sensor did fall off. I'm not sure 100% sure if it was already like that or not.

I will start following the hoses in the morning and see if I missed one or if one is dry rotted.
Attached Images
File Type: jpg IMG_20190816_125428_1565997164165.jpg (1,022.1 KB, 4 views)
dgram is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Honda CBR1000 Forum : 1000RR.net forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

 
For the best viewing experience please update your browser to Google Chrome