04-24-2020, 02:15 AM
My bike has been developing the low idle and stalling syndrome since it was almost new. At first it was hard to reproduce but with time and kilometers (60.000 Km) now it happens every time i get in traffic, it is annoying.
I can not read the DTC's but checked TP, IAT, O2, EOT sensors and IACV valve (each coil 105 Ohm). Everything looks right but while checking the signals to the IACV it confuses me 2 things
1- I get two differert types of signal. A) PWM like when switching ignition ON for 2 or 3 seconds, then it goes to zero, it also appears for less than one second at the moment of opening throttle or if you try to stall the engine (and these two last conditions are similar to heavy traffic driving, which is when issue takes place) B) Pulses randomly every now at then (I suppose the ones it controls the stepper motor with)
2- The signals are simetrical with the zero volt line as simetry axle. They switch between positive and negative.
I am gonna try to attach some photos
Anyone knows what type of signal is expected in each of the coils of the IACV valve?
Thanks!
So at last I think I can post the photos... This kinda PWM signal appears after switching ignition ON (for 3 seconds maybe), it also appears for less than one second at the exact moment of opening throttle from fully closed. As it is an old oscilo and because the speed (sec/cm) is quite low in the photo only appears a fragment of the whole signal, if you watched the video this signal goes from side to side of the oscilo screen because of a very simple optical effect.
![[Image: 1f534ca7f59c804caea661eac3ebd84d.jpg]](https://cb1100forum.net/forum/uploads/imp/202004/1f534ca7f59c804caea661eac3ebd84d.jpg)
this is only one of the coils, only one channel. It is strange that it switches between plus and minus. Both coil signals have same behaviour.
Then this is the other type of signal i found. It is like a short pulse but also plus and minus. They appear more often while trying to stabilize the idle speed, when stable they don't appear so often. Can someone tell me if this is ok?
![[Image: 25f154b67943f0f405804bf02e3503d4.jpg]](https://cb1100forum.net/forum/uploads/imp/202004/25f154b67943f0f405804bf02e3503d4.jpg)
I can not read the DTC's but checked TP, IAT, O2, EOT sensors and IACV valve (each coil 105 Ohm). Everything looks right but while checking the signals to the IACV it confuses me 2 things
1- I get two differert types of signal. A) PWM like when switching ignition ON for 2 or 3 seconds, then it goes to zero, it also appears for less than one second at the moment of opening throttle or if you try to stall the engine (and these two last conditions are similar to heavy traffic driving, which is when issue takes place) B) Pulses randomly every now at then (I suppose the ones it controls the stepper motor with)
2- The signals are simetrical with the zero volt line as simetry axle. They switch between positive and negative.
I am gonna try to attach some photos
Anyone knows what type of signal is expected in each of the coils of the IACV valve?
Thanks!
So at last I think I can post the photos... This kinda PWM signal appears after switching ignition ON (for 3 seconds maybe), it also appears for less than one second at the exact moment of opening throttle from fully closed. As it is an old oscilo and because the speed (sec/cm) is quite low in the photo only appears a fragment of the whole signal, if you watched the video this signal goes from side to side of the oscilo screen because of a very simple optical effect.
this is only one of the coils, only one channel. It is strange that it switches between plus and minus. Both coil signals have same behaviour.
Then this is the other type of signal i found. It is like a short pulse but also plus and minus. They appear more often while trying to stabilize the idle speed, when stable they don't appear so often. Can someone tell me if this is ok?