I'm trying to check voltage at 02 sensor. At idle or cruising it's showing like it should, it's fluctuating from about 2mv - 6mv. When I go wide open throttle it should go to about 850mv - 980mv, but it doesn't increase. My question is, how long does it have to be at wide open throttle before the increase takes place? And does anybody know what mvolt reading achieves a 12.5 to 1 air-fuel ratio?

 

correct me if im wrong, but dont you want a 14.7:1 air/fuel ratio? and you might want to check the tech articles. there is one about tuning your engine with your oxy sensor. it should have the voltage readings in there

 

a heated O2 senser will give quicker and more accurate reading than an unheated one. if you have an unheated senser let it warm up first before taking any volt readings. you also want 14.7:1 a:f ratio unless you really are ttrying to get it to 12.5:1 for some unknown reason.

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ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

 

Be advised! 14.7:1 air/fuel ratio is
what is known as chemicaly perfect ratio.
That is where is the theroedical proper amount of oxygen to burn all the fuel.
This is a good air/fuel ratio for idle and light cruise, especally with computer control
and emissions equipment and a cataylitic converter. The most thermal efficiant ratio is around 17:1 (best gas milege at cruise)
but, BUT is very lean and hard to achieve in
all cylinders all the time. Not a good IDEA!
If you want MAXIMUM HORSEPOWER! TUNE FOR 13.5:1. BUT even this is TOO LEAN! for sustained full throttle use. The motor WILL overHEAT and burn up inside! The BEST SAFE
MAX POWER AIR/FUEL RATIO is 12:1 to 12.5:1.

12:1 ...Not 14.7:1 !!!!

The extra fuel is nessessary to prevent
overheating in the combustion chamber at full throttle which soon leads to detonation and preignition. TRUST ME on this one.
Remember 12:1 That little extra fuel saves your motor
and at best costs ya 2 hp.

 

When you floor the gas pedal, the air/fuel guage should imediatly swing from around 14.7:1 to 12.5:1 and stay there till you let off. If it wants to return GET OFF THE GAS!
and fix it!!!! Just my Oh tu

[This message has been edited by F-BIRD'88 (edited November 03, 2001).]