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After you replaced IAT and MAP sensor, did you measure them to verify outputs matches values given in manual? Measured ECT? They put those tests in there to help you fix these kinds if issues. Measure twice, once at sensor itself, then at ECM connector to verify wiring in between to make sure proper signal reaches ECM.

I have looked inside ECM with Hondata. It's same as all Honda engines. Honda takes different approach than others who make specific ECM for each model. Honda uses same software and customise by turning options on & off.

ECT and IAT signal to ECM that there is cold-start condition and ECM provides fuel-enrichment along with opening IACV slightly for fast-idle.
 

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Honda: INNOVA125i(2010); CBR250R(2013)
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Discussion Starter · #22 · (Edited)
After you replaced IAT and MAP sensor, did you measure them to verify outputs matches values given in manual? Measured ECT? They put those tests in there to help you fix these kinds if issues. Measure twice, once at sensor itself, then at ECM connector to verify wiring in between to make sure proper signal reaches ECM.

I have looked inside ECM with Hondata. It's same as all Honda engines. Honda takes different approach than others who make specific ECM for each model. Honda uses same software and customise by turning options on & off.

ECT and IAT signal to ECM that there is cold-start condition and ECM provides fuel-enrichment along with opening IACV slightly for fast-idle.
Hi Danno, I was already with you in this movie and still.
Thanks for the help and support(y)
Last time you suggested me to replace the IAT, and it makes sense to me and I replaced it. According to the Honda's service manual there is no ability to complete all the tests on the IAT without "HDS pocket tester" special tool. The manual itself (P. 5-24) does suggested to replace a new IAT component for comparison with the suspicious IAT component, and this too was an incentive for me to buy a new IAT component. So the entire sensor-set was replaced with new one (because IAT+TP+MAP are all built-in at one unit).

I checked the ECT, and it was OK, and despite it was OK I replaced it not before I checked that the new ECT component was also OK, I did it as a preventative maintenance (66,000 km and a 9 year old motorcycle).

But what I can go back to check I will check again.
But it's going to take me a while to get to that, maybe next month?
What is this Honda's HDS tool???
Is it a diagnostic device that attaches to DTC(4 pin) like the set below?
Font Material property Software Rectangle Multimedia
Data transfer cable Font Material property Output device Screenshot
 

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Honda: INNOVA125i(2010); CBR250R(2013)
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Discussion Starter · #23 · (Edited)
Danno wrote in response to the issue of a jump at the main chain when the throttle is fully released at high rpm (LINK):
(LINK)
The ECU has separate "idle mode" setting and transition to "partial-throttle" settings may cause an abrupt jerk .

Most ECUs will turn off injectors when you release throttle at high-RPM.
...I usually just disable idle-mode by re-programming ECU... This prevents sudden jerking when you open throttle at low-speeds or let off throttle from high engine-speeds
(LINK)
Only issue with disabling idle-mode is cold-starts. ECU won't engage cold-start mode with fuel-enrichment and high-idle speed using IACV if it doesn't detect that TPS is closed. Not a problem if you live in warm climates.

...The slight jerk when letting off throttle at high-RPMs can disrupt smooth cornering at limit.
After all the efforts I have put in to bring the motorcycle to a proper and balanced working condition ("a line treatment"). After a year I can declare with complete confidence that all my motorcycle assemblies are working properly and go into a regular and routine maintenance schedules.
Yes, the "problem" I have with cold start is meets exactly the characteristics that grate Danno🤴 describes.

These are my options I face:
1.
To leave the ECU as it is. In winter add a very small opening of the throttle, about one degree in the throttle, thus simulating the IACV operation. Like I did this the last winter months I had left, when the temperatures dropped to 8°C.
And all the year(Winter and Summer) to enjoy the benefit Danno was mention.
2. To go to Honda's main garage and ask them to reboot my ECU. Maybe whoever touched my ECU also changed the fuel data to a lean mixture, and that's why I had signs of white dots on the plug? So reboot ensures reset all the "nonsense" done on my ECU.

I currently do not see a preference in option (2) over the (1), so I do not touch anything (choose the first option).

It was really challenging year, far beyond what I could have expected when I bought my neglected motorcycle(LINK). Thanks to all the forum members who supported and helped me along the way.
🍺Thank you all very much🍺
 
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