Originally Posted by v1p3r
(Post 534879)
On which car, on which fuel, on which planet? |
Originally Posted by chetanhanda
(Post 535636)
:) This is not the issue , he is reporting perfect lambda readings @ idle ... |
Originally Posted by drpullockaran
(Post 534854)
At idle you should have a 11:1 OR 12:1 ratio when the car is warm and if not a ratio of 11:1 is the norm. The other thing you mentioned is that the O2 sensor shows a reading of less than .6 to .7volt and if thats the case you are running rich because I believe that higher the readings more is the oxygen level and leaner the fuel mixture. It could also be that if you have the 4 lead O2 sensor the heater coil of your sensor has gone dead. If the 2 lead version is used in your car then a rich mixture is the resultant and possibly your flame front from the spark plug is being quenched partially resulting in hestitation from revving. Oxygen Sensor Information Bye and wear your seat belts. |
Originally Posted by Octavia2
(Post 535896)
Chetan, Agreed with you - my car runs better @ cold too... possibly bcoz it is in open loop till 02 gets heated up as well... VAG has measuring blocks - one group shows retard for cylinders - none shown. 6-8 degress not % - sorry typo. Flipsyde, my car drives great otherwise - you should ride in it to feel the mid range. :) Thanks, |
Originally Posted by drpullockaran
(Post 537510)
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Originally Posted by drpullockaran
(Post 534854)
At idle you should have a 11:1 OR 12:1 ratio when the car is warm and if not a ratio of 11:1 is the norm. |
Originally Posted by flipsyde
(Post 538599)
@chetanhanda - when your trying to spin your wheels i'm sure you don't let the clutch go at cold start RPM's (1200-1500). what i mean is in a cold engine when you punch the throttle it takes .5 sec before it gives you the revvs unlike a hot engine. its always been this way for me. |
Originally Posted by Octavia2
(Post 535896)
Chetan, Agreed with you - my car runs better @ cold too... possibly bcoz it is in open loop till 02 gets heated up as well... VAG has measuring blocks - one group shows retard for cylinders - none shown. 6-8 degress not % - sorry typo. Flipsyde, my car drives great otherwise - you should ride in it to feel the mid range. :) Thanks, |
Originally Posted by chetanhanda
(Post 539804)
:) dude !! first of all relax !! u are mixing up 2 things we are dscussing his AFR at idle, please read the 1st post. why would anyone want to idle at <14.7 ?at idle u want min emissions without stalling the engine It makes sense to have 11 to 13 when u want power or under hard accelaration. |
Originally Posted by drpullockaran
(Post 542174)
I thought it was near impossible to idle without stalling with a mixture set at ideal stoichiometric ratio in engines which are not designed for leanburn. To prevent stalling the ratio of petrol is usually increased at idle and more over we are talking of E10 fuels in India. Engine Modification A Literature Review Based Assessment on the Impacts of a 10% and 20% Ethanol Gasoline Fuel Blend on Non-Automotive Engines: 5. Fuel System and Control System Definitions |
Originally Posted by chetanhanda
(Post 543059)
if the wideband shows green or says its ideal we accept that as perfect ... now if u go and burn the same fuel in a lab under near perfect conditions it may be diff.. but we follow what the wideband says its the benchmark for us. e.g If I use regular pump gas 97 octane I will look for green zone on my AFR = normal during idle, again if I were to tune with a crazy higher octane race gas I would again look at my AFR and make changes.. to fuelling and timing...i would have diff maps for diff octane so at a given AFR the race gas is going to give me more power... BTW the second article is on open loop non automotive systems so I wouln't use that as a reference. the minute the o2 sensor gets warmed up the car goes into closed loop.. are we on same page.. or r u still saying u should idle at 11:1 as per lab report when ur foot is of the throttle using pump gas? if u were running a high compression high octane race gas with crazy high lift hi duration cams i would keep my AFR more rich in order to keep it from stalling or run more smoother maybe something like 13.5 etc etc .... but on a stock car with pump gas I would follow the AFR and say idle according what the AFR says is perfect "14.xyz" |
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