Fueling at altitude, 1150

[Sergeant Pluck]

Does the ECU adapt fueling for the richness caused by riding at high altitude? I know there's an air sensor in the air filter housing lid, but that's for temperature, not oxygen content, right?

One of the passes we'll be going over on our forth-coming trip is nearly 5000 metres and I was wondering if the bike would cope by itself or not.

I have a sneaky plan that if the bike doesn't adjust itself for altitude, I'll take along my yellow CCP and use that to lean things up when get high into the mountains.

What do you think?

Pluck

 

[Deak]

I always thought the lamda sensor in the exhaust controls fuel mixture by analysing the oxygen levels.

 

[sparkplug]

As Deak said it's all automatically compensated for.

Just put the petrol in and ride

 

[Sergeant Pluck]

Thanks guys - doesn't the lambda only affect the fuelling at idle though? Or have I got that wrong?!

Pluck

 

[carbold]

Thanks guys - doesn't the lambda only affect the fuelling at idle though? Or have I got that wrong?!

Wrong

 

[Sergeant Pluck]

Wrong

Right!

One more thing not to think about then!

Cheers

 

[Bezzler]

High stuff

The bike was ok it was me that was 'Pinking'

 

[Invicta Moto]

Mine was wheezing on the Bonette and that's much less than 5000 metres at 2802.

 

[littleredrooster]

Thanks guys - doesn't the lambda only affect the fuelling at idle though? Or have I got that wrong?!

Pluck

Correct-a-mundo. Closed-loop fuelling (i.e controlled by the lambda sensor) only occurs at and just above idle. Everything else is as per pre-loaded fuel map according to which cat-code plug you're using. If that wasn't the case, what does the cat-code plug do????

 

[Sergeant Pluck]

Correct-a-mundo. Closed-loop fuelling (i.e controlled by the lambda sensor) only occurs at and just above idle. Everything else is as per pre-loaded fuel map according to which cat-code plug you're using. If that wasn't the case, what does the cat-code plug do????

Thats what I thought!

Ah well! I'm not too concerned - I'm still going to bung the CCP in with my spares, you never know, and then forget about it

Cheers all.

Pluck

 

[Guzzler]

Don't worry about it. 13,000 foot mountain pass in Colorado, USA my GS had no issues what-so-ever. Actually ran better.

 

[Schtum]

Correct-a-mundo. Closed-loop fuelling (i.e controlled by the lambda sensor) only occurs at and just above idle. Everything else is as per pre-loaded fuel map according to which cat-code plug you're using. If that wasn't the case, what does the cat-code plug do????

All of which is a very good reason for investing in a Power Commander. For Bee Emms, unlike other models, these come equipped with wide-band lambda sensors which allow the bike to run in closed-loop mode throughout the rev range.

 

[carbold]

I'm not sure you are right guys, I think the lambda probe works at any time and revs, continuously giving a signal to the ECU.
Have alook here http://www.answers.com/topic/oxygen-sensor?method=8

"By measuring the amount of oxygen in the remaining exhaust gases, and by knowing the volume and temperature of the air entering the cylinders amongst other things, an ECU can use look-up tables to determine the amount of fuel required to burn at the stoichiometric point (14.6:1 air:fuel by mass for gasoline) to ensure complete combustion."

The preloaded fuel map you are talking about still needs input from the probe.

 

[Schtum]

I think the lambda probe works at any time and revs, continuously giving a signal to the ECU.

It doesn't. Only wide-band lambda sensors have that ability. The ones fitted to bikes are, almost invariably, narrow band. Above 3K revs or thereabours the ECU switches into open-loop mode.

 

[Frank Warner]

Even on bm bike without lambda sensor/s the altitude is corrected for - using an air pressure sensor ... think you'll find the same sensor is in the EFI even if a lamda sensor is also so used.