Hi everyone, I have a problem with my bike, I bought it new in 2008 and now covers slightly over 10,000 Kms, here's what happens.... as usual when I started it in the morning, it idles nicely at 1200 rpm, but as soon as I push the "D" button, the idling increases to 1600 rpm and the centrifugal clutch begins to engage and drives the bike forward without throttle input... if the bike is in neutral and I give it some throttle and release, the engine speed increases and reduces, but it will not go down to normal idling speed but remains at 1400-1600 rpm... I have to apply the brakes to prevent the bike from creeping forward whenever I stopped at the lights... I have checked that the throttle cables are not sticking, the IACV is working, the TPS is ok... so what else could be the problem? Any advice is greatly appreciated. Thanks for reading...
Engine idling increase when "D" is engaged
- Thread starter Gundam
- Start date
I'm in sunny Singapore, the coldest temperature we have here is 24 degrees C, I have also checked the vacuum hoses, all ok... just today I did some experiment... I remove the left side fairing and start the engine and as usual it idles at 1200 rpm, I gave it some throttle, and it idles at 1400-1600 rpm, I then cover the air intake hole to the air filter with my hand and the rpm goes down to below 1000 rpm, almost stalling the engine, and when I release my hand, it returns to 1200 rpm idling speed... just to test it further, I engage "D" and the rpm increases to 1600 rpm, again I cover the air intake and the rpm drops to below 1000 rpm, but when I release it, the engine speed increases to 2000 rpm briefly before settling down to 1600 rpm... so either the IACV not working properly or it is something else... but what?... I don't suppose other riders of DN-01s experience this before.... sigh... will take it apart again some other day to find out what is wrong....
Finally found the source of my high idling problem... it's the ECT sensor, from what I can deduced, the resistance values have changed, therefore it is sending a wrong signal to the ECM, telling it that it is freezing outside and the ECM responds by instructing the IACV to open the air passage more, increasing the idling speed....
I am waiting for the new ECT sensor to be shipped over, and in the mean time I have machined a spacer to prevent the IACV to open too much, therefore reducing the idling to as before...
Will update when I have fitted the new sensor....
I am waiting for the new ECT sensor to be shipped over, and in the mean time I have machined a spacer to prevent the IACV to open too much, therefore reducing the idling to as before...
Will update when I have fitted the new sensor....
Ok fellas... my new ECT sensor has arrived, but after connecting it, the problem still persists...arghh!... so the problem is not the ECT sensor after all... well back to square one... luckily my home made cure comes in handy... will update further if I have any breakthroughs...
Yes, it certainly is!... my solution of a simple spacer installed inside the IACV cured the symtoms... but I still wanted to find out what actually is at fault...
That's the first thing i did. Engine idles at 1200rpm plus maybe another 20-30rpm which does not show as the tacho is incremented in 100rpm steps. 1200rpm is as per spec (+-100rpm). But when it does i am struggling to push the bike in reverse with my feet (i have to put it in neutral). So basically all of this tells me the clutch is engaged which it should not be when you come to a stop. I also need to engage the brake to stop it from creeping forward on the flat ground. All of this tells me if i could drop the revs by 100rpm it would be much better. I had over dozen bikes and none have idles so high from memory. More like 900rpm or so.
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Similar but not the same: I have an NT700V which has the SAME engine (680cc) with a standard 5 speed tranny. When I start it up, it idles @ roughly 1800 rpm till it gets warmed up and then idles @ less than a grand. Maybe dropping the idle to a grand WILL work or at least help till the problem can be solved!
Totally agree. Because the manual calls for 1200rpm I can't think of any other ways to drop the idle down to 1000rpm or so other than using spacer at IACV valve or hacking into the computer which I can't do. Obviously some bikes idle at more acceptable rpm like yours above but mine does not so I will have to do the mod. I guess I am just surprised that Honda calls for standard 1200rpm idle plus or minus another 100rpm! Jeez, I would hate to have it idle at 1300rpm!! Anyway I will update once I find enough spare time to do the job which may take ages.
Just for my understanding, DID your bike EVER idle @ Honda's factory prescribed 1200 rpm with NO problems? Changing the way a bike was "designed" to perform does NOT seem to be the correct way to fix a problem unless it WAS a design defect!
Hi Gizmo, i am not able to give you an answer because i bought the bike second hand. Short time after i purchased it it started to develop uneven idle as described before due to the loose battery terminal. I can't recall the idle speed in the early days but i do remember i did not have those problems. (ie, creep...) I think you are suspecting it may be something else that's causing it but i am unable to tell until i take more things apart. At this stage i think the easiest 'fix' would be to add spacer. In the process i may discover something else but i am not holding my breath. I will post an update once i get around doing it. In the meantime the bike is rideable so this will probably take a while.
Probably both. I was hoping by disconnecting battery would reset the computer. I have not read the manual yet in that regard but as I mentioned before I disagree with Honda spec calling for 1200rpm to start with. I believe this is to high. You said yourself your bike is stable at 1000rpm which I think is far more reasonable. Why Honda is calling for 1200 is beyond me and that is why I think I will not be able to fix it via computer but only by adding a spacer.