add Choke to s2r 1K

[Speeddog]

It's not set for 1000 RPM.

It's set for 1000 total engine revolutions since startup.

It's an enrichment strategy for cold starting, not an idle speed strategy.

[pmazdan9]

Ah, got ya! That's interesting. Do you know more about how it works?

In any case, idle can be set in ECU, so it works one way or another.

[Speeddog]

Setting idle RPM in the ECU is only useful if there's an idle air valve, and it's then depending on that device to operate properly, which they do not always do.

[Howie]

Also keep in mind that before changing the program in the computer you must make sure all basic settings are good.  If, for example, TPS is not set correctly or malfunctioning so idle speed is off.  Go into computer, set speed.  Down the road the real problem is fixed, now idle speed is wrong.

[DuciD03]

…. [popcorn]… I re-read and am following along ...need more toquilla...

... [bow_down]…. .

[pmazdan9]

Setting idle RPM in the ECU is only useful if there's an idle air valve, and it's then depending on that device to operate properly, which they do not always do.

Why is it not useful if a motorcycle doesn't have one?

Also keep in mind that before changing the program in the computer you must make sure all basic settings are good.  If, for example, TPS is not set correctly or malfunctioning so idle speed is off.  Go into computer, set speed.  Down the road the real problem is fixed, now idle speed is wrong.

[ducpainter]

Why is it not useful if a motorcycle doesn't have one?

Because there's no connection between the throttle bodies and the ecu to make it happen.

[pmazdan9]

Because there's no connection between the throttle bodies and the ecu to make it happen.

I understand, however my ECU makes it happen without stepper motor in place. Are you saying it's impossible, or not efficient, and if so, why? I assume the way it works is it inject more fuel, as I said before, so it's very much the same as choke/enrichement circuit - making mixture richer and consequently increasing idle without adjusting amount of air coming in.

[ducpainter]

I understand, however my ECU makes it happen without stepper motor in place. Are you saying it's impossible, or not efficient, and if so, why? I assume the way it works is it inject more fuel, as I said before, so it's very much the same as choke/enrichement circuit - making mixture richer and consequently increasing idle without adjusting amount of air coming in.

There's a difference between using it to set enrichment, and idle speed.

If you are raising the idle speed by adding fuel, I'd suggest your TB's, or map, are not set correctly in the first place.

If you're old enough to remember cars with either manual, or automatic, chokes they also had a mechanism to increase throttle position when the choke plate was closed to avoid stalling. The simple addition of fuel won't raise idle speed unless the base mixture is too lean for the throttle position.

[pmazdan9]

There's a difference between using it to set enrichment, and idle speed.

If you are raising the idle speed by adding fuel, I'd suggest your TB's, or map, are not set correctly in the first place.

If you're old enough to remember cars with either manual, or automatic, chokes they also had a mechanism to increase throttle position when the choke plate was closed to avoid stalling. The simple addition of fuel won't raise idle speed unless the base mixture is too lean for the throttle position.

Bike's been just fully serviced (valves, tb sync), map is a base map for my set up, so it's not perfect, but feels like it couldn't be much better, if at all - that's a subjective opinion though, I know.

I though adding fuel would increase the idle (to certain point), but will run too rich, since more fuel and air does it but keeps AFR correct. I guess I was wrong all along then. Either my bike runs too lean, like you said, but I really doubt it (I'll check my plugs when I can to confirm) or it somehow adds more air as well. Remember there is an option to adjust idle in the map on my bike, so it is doing something Why would it be there if it didn't work properly.

OP, sorry I didn't mean to hijack your thread I'd say it's a bit weird that your bike stalls at 1100rpm for a start, seems like your idle is adjusted correctly by a stepper motor. I think adding a "choke" is just a band aid for another problem? Dragging clutch?

[ducpainter]

The ecu parameters are the same in your bike as in the models that have the stepper. Just because the parameter is there doesn't mean it's used.

[pmazdan9]

The ecu parameters are the same in your bike as in the models that have the stepper. Just because the parameter is there doesn't mean it's used.

From a programmer's point of view (I do it for a living) it would be a very poor software development. If there's a function that requires, to simplify, two devices (injector and air valve) to work as intended, and one is not there (air valve), it should not do anything, especially if it was designed to work with motorcycles with different setups.

It looks like this is the case though. I guess it indicates a very lean condition if it increases idle by 250 (or possibly more, just didn't try) just by adding fuel.

Interesting and informative conversation. Thanks

[Orange16]

What is the address in the file that you think is the idle control?  Which file are you using?

[pmazdan9]

I'm not messing around with the .hex file myself, just using software that reads it and allows to adjust certain settings.

[Orange16]

On the files for bikes without idle control that I looked at that line is 1000 at all points.

There is generally an ignition advance versus engine temp table where they pick up advance when the engine is cold, which can help idle them up a little.