AFR questions

[MaQuereau]

The autometer AFR, isnt it suppose to continuesly moving? or it will only move from Lean to Rich continuesly when we throttle?.. coz last time if im not mistaken even when the car is idle with engine running ofcourse, the meter always in motion lean to rich back and forth.. mine sometimes it moves and somtimes it just died without the lights moving at all..

is it suppose to move everytime?.. O2 sensor? i can say my engine is rather new so i dont think any problem with the O2 sensor being too old..

 

[taqu]

It's normal for that Autometer meter to cycle from reach to lean when idle, provided that ur idling is ok and consistent.

 

[MaQuereau]

my idling is ok and normal.. does it cycle non stop when it's idle? coz mine isnt so sometimes.. maybe wiring?

 

[gloss]

yea... tink its normal... can ask brother huakenny..

 

[gibod_78]

btw.. whats 'STOICH' means for Autometer AFRs ? yellow light..

 

[MaQuereau]

Stoich.. Lean Stoich Rich.. i would say stoich is the average.. maybe haha.. anyone..

 

[rizzo8]

btw.. whats 'STOICH' means for Autometer AFRs ? yellow light..

Simply means stoichometry, meaning your afr is at optimum at that point in time. what this means is if you could weigh the amount of fuel and air your engine is consuming, it'll be at 14.1 : 1 ratio (air : fuel).

another term to indicate stoichometric ratio is your o2 sensor or lambda sensor reads lambda = 1., that is, ratio of air required and actual air intake. Lambda > 1 is lean, while lambda < 1 is rich mixture.

At stoichometric ratio, minimum HC and CO emissions, but max Nox emissions. And thats what your catalytic is for.

 

[Battousai]

Stoichiometric is actually at 14.7:1 air:fuel for a petrol engine.
A narrowband AFR gauge, like the autometer will only tell u if ur engine is running rich or lean. If you want to know exactly HOW rich or HOW lean, you'll need a WIDEBAND AFR gauge.

I happen to have one for rent, ideal for tuning or checking the AFR of modified cars. If you're interested, PM me or email [email protected]

 

[delphinium]

I've got this from my Autometer AFR manuals:

.. provided the O2 sensor and AFR meter is in working condition ..

"When the engine is at heavy load, the monitor should indicate rich. At cruising load the monitor will appear to be bouncing back and forth between rich and lean. This is normal. The computer is constantly adjusting the air/fuel ratio for performance and low exhaust emission"


Mine is showing lean at idle. I guess this is due to I set AFC to -7% to lean out the mixture. I just thought that at idle i dont need that much of fuel.

 

[MaQuereau]

i know what was the problem.. my exhaust sensor gone.. screwed up, so i changed to another one.. now it's working perfectly.. Yahoo.. thanx guys..!