Jason Fletcher
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| posted on 25/7/08 at 08:20 PM |
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HELP!! What lowers Lambda readings?
Hi guys
trying to set up my Busa tonight and I can get all the readings down apart from the Lambda. I need to get it to between .97 and 1.03 and the lowest I
can get is 1.15. I have reduced the fuelling on both the regulator and the Power commander and nothing seems to help anyone got any Ideas??
cheers
jason
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froggy
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| posted on 25/7/08 at 08:24 PM |
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you need your co and hc readings and what temp your cat is at to get more ideas. high lambda is usually a weak mixture and your hc readings will show
very low co and higher hc due to the weak mixture not burning properly
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tks
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| posted on 25/7/08 at 08:25 PM |
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Spark timeing is important to... (to burn all the fuel properly and as late as possible..)
if you supply more air to the engine it will run leaner... if you supply less air to the engine it will run richer...
you will need to know the numbers meanings...
[Edited on 25/7/08 by tks]
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Jason Fletcher
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| posted on 25/7/08 at 08:36 PM |
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The CO hardly has a reading 0.001 sometimes and the HC is only 30 and I can have up to 200. The cat is proper hot!
Am I too lean? I would not have thought so cos I started with a map that actually increased the fuel at high idle.
Edited to say I have no way of adjusting the spark timing.
Jason
[Edited on 25/7/08 by Jason Fletcher]
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jollygreengiant
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| posted on 25/7/08 at 08:51 PM |
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Base emission readings should be only used for idle settings. Higher than idle readings are a different set of readings altogether.
If you lambda value is higher than 1.0 (perfect combustion burn) then I would suspect a lean mixture.
If you are getting intermittent high HC then I would suspect a faulty air valve or the engine is scavenging for fuels to burn (i.e. sucking in oil
from the breather system.
With the co barely reading 0.001, then I would suspect that the mixture is far too lean. Try increasing the mixture to give a hot cat reading of about
0.3 (+/- 0.1). Also check for air leaks in the exhaust system (sucking air in, not blowing exhaust gases out) between the exhaust flange and the
cat/lambda sensor.
Always try and work in a logical progression.
I hope this helps.
Beware of the Goldfish in the tulip mines. The ONLY defence against them is smoking peanut butter sandwiches.
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stevebubs
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| posted on 25/7/08 at 08:51 PM |
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Read this
Then a rambling page that takes a while to find what you want
quote:
To effectively convert these 3 components into harmless carbon dioxide, water and nitrogen in the catalytic converter, the engine must be
operated close to lambda 1 (1:14.7 AFR), i.e. the efficiency of combustion is greatest close to lambda 1. But lambda 1 is almost impossible to achieve
by control engineering, which is why the control unit continuously (several times each second) produces mixtures alternating between lambda 0.97 (rich
mixture) and 1.03 (lean mixture). Under these conditions the voltage generated by the lambda probe varies between 0.2 volt and 0.8 volt depending on
the exhaust gas composition.
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marc n
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| posted on 25/7/08 at 09:08 PM |
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you are running far too lean, where are you based ???
i would run std fuel pressure ( busa std ) and alter through power commander, and you should get it spot on
cheers
marc
please email rather than u2u
direct workshop email ( manned 8am till 6pm )
www.mnrltd.co.uk enquireys to :-
chrismnrltd@btinternet.com
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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Jason Fletcher
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| posted on 25/7/08 at 09:11 PM |
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I spoke to a test centre today so I think I have the details of the requirements which are:
Idle test is for CO only and needs to less than 0.5 (which it is)
High Idle 2500 - 3000 rpm needs a Lambda reading of .97 - 1.03 the CO needs to be less than 0.3 and the HC less than 200.
Thats all good information and I will give it a go again Monday.
I would never have guessed it was too lean after everyone says reduce the pressure.
Thanks
jason
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Jason Fletcher
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| posted on 25/7/08 at 09:12 PM |
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Hi Mark
Im in Kenilworth (a walk from stoneleigh which I guess you know)
Jason
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adithorp
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| posted on 25/7/08 at 09:25 PM |
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Sound too weak...or an air leak on the exhaust can give a high lambda. If the cat is hot (it takes a good run or a long period of high revs to get it
working) then the CO will read almost zero at the tail pipe. My R1 read zero on the CO but only just made the HC limits (and varied a lot)when I got
the lambda right.
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Jason Fletcher
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| posted on 25/7/08 at 09:41 PM |
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Also, my busa has 8 injectors and the power commander only connects to the top 4. Do all 8 work at the same time or does the top and bottom ones work
at different RPM's? Is there a chance the power commander is not doing a whole lot at 3000rpm?
Thanks
jason
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marc n
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| posted on 26/7/08 at 06:53 AM |
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hi jason
dint know if you where near to us as you could have brought your car and hooked up to our anayliser, keep std fuel pressure and use the power
commander, thats how i have done every busa,
a good start is go four richer from where you are, eg instead of minus ten go -6
you only need small changes in value to get big changes, what year busa is it
please email rather than u2u
direct workshop email ( manned 8am till 6pm )
www.mnrltd.co.uk enquireys to :-
chrismnrltd@btinternet.com
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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Jason Fletcher
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| posted on 26/7/08 at 08:56 AM |
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Marc
its a 08 busa. The map that comes with the P.C is 10 not -10 in the 2750 rpm in throttle possition 2.
Jason
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Jason Fletcher
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| posted on 30/7/08 at 08:42 PM |
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Go there in the end! The air filter I am using must be less restrictive than the airbox on the bike cos the fuel had to be really pushed up to get the
emmisions right.
thanks for the help.
J
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