question about wideband readings

[LTUDSM]

hey,dsm'ers i got a question about my wideband readings :

what is a normal (perfect) idle readings on Wideband o2? my readings right now are not steady,it jumping from ~14.5 to ~15.7 is it good? if not what i have to do?!
at wot im getting 10.7.Im newbie in a Wideband world,but what have to do? to lean down or to make a lil richer??? thanks alot
sorry for any mistakes,my English is not a primary language ...

 

[The_EE]

hey,dsm'ers i got a question about my wideband readings :

what is a normal (perfect) idle readings on Wideband o2? my readings right now are not steady,it jumping from ~14.5 to ~15.7 is it good? if not what i have to do?!
at wot im getting 10.7.Im newbie in a Wideband world,but what have to do? to lean down or to make a lil richer??? thanks alot
sorry for any mistakes,my English is not a primary language ...

Do you have cams? That could be why its jumping, if not, check for exhaust leaks.

You are running rich if your AF Ratio is 10.7, you need it lean it out, shooting for about 11.4 on 91. Every car is different though, you might be able to get away with leaner as long as it doesnt knock.

 

[LTUDSM]

i dont have cams, and no leaks around exhaust what so ever.i thought that too,that i have a leak somewhere around exhaust ,i checked that out ,but didnt find anything

 

[bostonhatcher]

Are you running on stock injectors with stock tune? If so you have a bad sensor.

 

[LTUDSM]

i got a Fic 550's, and using a Maf setup along with a Maft Gen 2 unit

 

[Black_Bullet]

During idle and cruising your air fuel ratio is suppose to cycle therefore its not going to sit on the exact same number... This is called closed loop operation when the ecu is constantly trying to adjust fuel trims and values in response to certain random conditions.
On a 91 octane car ( depending on the level of tuning available ) Id only shoot for 11.1 air fuel ratio... On 93 octane 11.3- 11.5 would suffice... I wouldnt go leaner than that though.
I dont recommend trying to lean out the afr from doing stuff hacking your mass or purposely drawing in unmetered air.

 

[LTUDSM]

o read about good readings before,and a lot of guys are saying,that 12.5 is a perfect A/F ratio,m i right???

 

[bostonhatcher]

i got a Fic 550's, and using a Maf setup along with a Maft Gen 2 unit

Did you tune your car? If you didn't tune your ecu then your fuel trims are gonna be pullin like crazy.

 

[GVR4592]

http://www.max-boost.co.uk/max-boost/internet_articles/Air fuel metering.htm

 

[forcefed 95]

o read about good readings before,and a lot of guys are saying,that 12.5 is a perfect A/F ratio,m i right???

Well at idle perfect or stoich. is 14.7. Other wise 12.5 is to lean to be out and getting into the turbo. You wanna stay around 11.1. if not a little richer to be safe. Depending on your tune of course.

 

[LTUDSM]

Did you tune your car? If you didn't tune your ecu then your fuel trims are gonna be pullin like crazy.

yeahh i did some adjustments with Maft Gen 2 ,because when i installed 550's the car ran like crap,because it was way to rich,now i leaned down a lil bit ,and now its way better then it was before.But still cant get a 11.1 on 93 octane.The best what i did is 10.7

 

[bostonhatcher]

If you've ever seen a car get a real tune, there are so many fuel tables and maps that there's no way you can hit it just right with an afc.