Engine shut off while downshifting

[katflap]

Originally Posted by 2LZ

All good stuff katflap and probably right on, especially when it comes to the "canned mapping" from Delphi.

Question though, since this is a closed loop system after it reaches operating temp, (open loop or choke mode should run on a set mapping), wouldn't then the O2 sensor (along with MAP, etc..) take over and adjust the injector pulse width, as needed, to attempt to reach it's optimum 14.7 to 1 or as close as possible?.....or I wonder if by EPA standards, as you suggest, don't allow that anymore and run them lean, even in closed loop?...which really makes no sense because usually a lean condition creates more HC's. I've never figured that one out. I know way back when I was a CA smog tech, anytime we saw high HC's, they had an air leak somewhere.

It would be interesting if someone could get a sniff at full operating temp at both idle and cruise rpms.

Until the engine reaches a pre defined operating temperature and the 02 sensor is up to a working temp your bike is in open loop.

In open loop it uses all the other sensors to reference against the map tables in order to try and maintain a 14.6:1 air/ fuel ratio when idling, gentle acceleration or cruising.

Without the O2 sensor in use it has no way of checking that this has been achieved.

Once the engine temp is around 25 degs C and the O2 sensor is up to temp your bike enters in to closed loop.

In closed loop the O2 sensor is been used as well. Now the bike can monitor the emissions and now knows if the air fuel ratio is correct and will make small adjustments many times a second to maintain 14.6:1 A/F .

Your bike will only remain in "true" closed loop when idling, gentle acceleration and cruising.

At any other time a different fuel/air ratio is required. There are a number of "overrides" that can come in to play when this occurs to give a richer or leaner mixture.

I didn't know that a lean mixture gives high HC's , that doesn't make sense to me but I have no knowledge about this

here is a graph of my RX3 showing a zero injector pulse when the throttle position hits zero

And the next graph is of my engine temp before I changed the thermostat. the temp only peeks at the end because I came to a stop and let it idle. (temp in degs C )

[katflap]

Originally Posted by Sullybiker

Someone should start collecting some data on this, particularly ambient temperature, that kind of thing.

ECU updates are a common thing, but there's some logistical problems involved, as you can either present the bike to a dealer, or (and I suspect this would be more likely) mail the ECU somewhere to get the firmware flashed.

This problem isn't unheard of on EFI bikes, my own Ninja had a rep for it (I mentioned it up thread) but mine was not affected. I think the cure was a more aggressive idle fuel map.

Interestingly, though I've not ridden an RX3, a common remark is that the bike has excellent fuelling, by no means common on EFI bikes. It would suggest Zong has done a fair bit of work in this area.

Interesting to know that other bikes have had a similar issue.

Think Its worth pointing out that the RX3 in the USA were a later edition to the RX3 in the UK and had an updated ECU fitted , perhaps this is why the UK bikes might suffer a bit more from this problem.

I agree, 99% of the time the fuelling from the engine management system on these bikes work perfectly

[Sullybiker]

Originally Posted by katflap

Until the engine reaches a pre defined operating temperature and the 02 sensor is up to a working temp your bike is in open loop.

In open loop it uses all the other sensors to reference against the map tables in order to try and maintain a 14.6:1 air/ fuel ratio when idling, gentle acceleration or cruising.

Without the O2 sensor in use it has no way of checking that this has been achieved.

Once the engine temp is around 25 degs C and the O2 sensor is up to temp your bike enters in to closed loop.

In closed loop the O2 sensor is been used as well. Now the bike can monitor the emissions and now knows if the air fuel ratio is correct and will make small adjustments many times a second to maintain 14.6:1 A/F .

Your bike will only remain in "true" closed loop when idling, gentle acceleration and cruising.

At any other time a different fuel/air ratio is required. There are a number of "overrides" that can come in to play when this occurs to give a richer or leaner mixture.

I didn't know that a lean mixture gives high HC's , that doesn't make sense to me but I have no knowledge about this

here is a graph of my RX3 showing a zero injector pulse when the throttle position hits zero

And the next graph is of my engine temp before I changed the thermostat. the temp only peeks at the end because I came to a stop and let it idle. (temp in degs C )

Attachment 8236
Attachment 8237

That's really interesting. What did you pull these from? I note the MSDOS 8-character names, so I know it's probably old/legacy software

Your injector pulse floor is showing zero, is that a demand? (the bike idles at one point for about five seconds by the look of it) I'm guessing there is a standard idle pulse at this point or the engine would cut.

[katflap]

Originally Posted by Sullybiker

That's really interesting. What did you pull these from? I note the MSDOS 8-character names, so I know it's probably old/legacy software

Your injector pulse floor is showing zero, is that a demand? (the bike idles at one point for about five seconds by the look of it) I'm guessing there is a standard idle pulse at this point or the engine would cut.

Yeah its "PCHUD" the only PC based software (windows 3.1) that we know of that works, pretty ancient

Not quite sure what you mean by "demand" , I've added a new pic below , with RPM, to try and put it in to context.

This log I did some time a go , with my laptop in the top box

So at marker 1,

I probably came up behind a car but because of on coming traffic I could not over take, shut the throttle for engine braking. at this point the injector pulse drops to zero but the RPM is still about 5500.

Marker 2

Probably I blipped the throttle whilst changing to a lower gear. (note a blip of fuel injected)

Marker 3

Opened the throttle up, probably clear to over take. Injector pulse returns

[Sullybiker]

As if on cue for me mentioning it not just being an RX3 thing, here's another Ninja 300 stalling story at my other motorbike online home:
http://www.kawasakininja300.com/foru...ting-stop.html

And a quote from another thread on the issue, which recommends exactly what @2LZ suggests:

if I remember correctly it has to do with engine braking.. no gas is used with engine braking, and then when yo pull the clutch the engine dies because it was no getting any gas to begin with...

easiest way to prevent this from ever happening, is get used to blipping the throttle at clutch pull..

[fjmartin]

Yesterday and today I started having the engine die when I pulled in the clutch and just like the last time I checked the valves and the intakes were fine but the exhausts were tight again. Adjusted and now it's running fine. Had to do this adjustment without waiting the 34 hours to cool since I have to leave in the early am to make it to the Mojave Desert with my group.

[Inroads]

I would not think that waiting 24 hours to adjust valves is necessary....maybe 5-6 hours.
Would like to hear more about your Mojave desert ride (Joshua Tree NP) ?
As I will be visiting there prior to my Baja ride.

[fjmartin]

I'll make sure to post pics links and a ride report. Thanks!

[Huck369]

Pretty sure my issue is a fueling related issue.....I wonder how easy it'd be to swap in a Carb and see how it ran....

I will check my valves again, but I've already checked them once since it started...and mine doesn't die when I let off the throttle, it drops down to, and idles fine, for 10-45 seconds, then it'll out of no where die.....always starts back up, but it is annoying

[fjmartin]

Just an update. Been riding hard all week in Death Valley and surrounding areas avg 200 miles per day and the bike hasn't died once since I did the valves on Sunday.

[AdventureDad]

Cant wait to hear all about it...and pics of course, Martin!

[madsocial]

Martin that's great news. I hope it continues. Once the weather breaks here in NY, I'll keep you posted to see if ours dies again.

[fishman10]

mine does it to Dave ,,more than it should , an more when its hot ,,,tried everything,, still does it even tho the valves where adjusted by csc,,I think there is a problem at the ignition switch,,,,since that is the only place either I or csc has checked.

[2LZ]

Originally Posted by fishman10

mine does it to Dave ,,more than it should , an more when its hot ,,,tried everything,, still does it even tho the valves where adjusted by csc,,I think there is a problem at the ignition switch,,,,since that is the only place either I or csc has checked.

I stole this from Jay in Miliptas (shamelessly, I might add) from post #44. I wonder if this is something that would be good for all of us to do????

"The used to be another RX3 web group I followed, I think a guy named Andy (cat herder?) posted that he started having stalling problems and found the ignition switch assembly had some dust inside. Seems the dust fluffered the contactulators and wouldn't let the pixies go to the wires they wanted to dance in.

I seem to recall he used a couple shots of electrical contact cleaner/lube. I think he also covered the holes in the switch body. He never reported another repeat of the stalling up until the web site vanished."

[Azhule]

I read on the CSC Blog, they like to use "Lucas Fuel Treatment and Upper Cylinder Lube" to help with this issue... might be worth a try for everyone having those problems (did I say this already somewhere?? )

Lucas Fuel Treatment will (over time) clean things up, but where it shines is it's lubricating and 'Fuel Tension' properties... it contains a chemical known as " PIB " (Polyisobutylene)...

PIB basically helps in 'controlling/evening out fuel molecule/droplet sizes to help in a more complete combustion cycle', when being sprayed out a fuel injector or after it hits the emulsion tube on the carby... all the fuel droplets want to be a similar size ready to go bang... might be really important when cutting the fuel down to idle on these fuel injected motors ??

Good thing is that, this version of Lucas Fuel Treatment, can (usually) be bought by the gallon for about $22 + taxes after an online coupon at your local Advance Auto Parts... only need to use 1 to 1.5 ounces of Lucas Fuel Treatment for every 5 gallons of fuel, so a little bit of the stuff goes a long way

Only one bad thing, and I said it earlier... it will clean things like carbon, varnish, gum, and other buildup seen in the fuel/combustion process (fuel gauges have been helped too in some cases)... but it takes several tanks and a few thousand miles to actually see the cleaning happen...

"Just stick with it" was what I would tell customers on a budget, not wanting to spend $140 for the "4 stage fuel system/top end cleaning" we would perform at the stealerships... This Lucas Fuel Treatment is still a good product for the price point, has great lubing and combustion helping properties / but has a much slower "cleaning process" compared to other fuel treatments out there