CharlieGSanD

i have noticed that around town & @ part throttle my A/F stays pretty close to 14.5-1 but ive noticed that as i increase throttle, the A/F drops to 12-1 @ about 70% 11-1 @ 85% & as low as 9-1 @ WOT.... is this much "enrichment" normal?

also when the car idles (in Vac) for a few seconds (30 or more) ive noticed that the A/F will slowly drop from 14.5-1 to as low as 8.5-1 then slowly climb back up. is this just the sensor reacting slowly to a rich pocket of exhaust gas, or possibly the ECU modifying the fuel trim to compensate for a vac leak? (it is not the usual "flicker" that the LED guages get, its more slow & gradual)

berkel

9:1 is waaaay rich, but what kind of A/F ratio meter do you have? Most in-car a/f meters that run off the O2 sensors aren't "that" accurate except for a very narror band near stoich.

So, if it read about 14.5:1, you're probably about stoich. If it read anything above that, you're lean, below that, you're rich, but you probably don't know exactly how rich or lean.

IOW, I don't think you're getting as rich as that? It should oscillate back and forth, going rich-lean-rich-lean as the ecu compensates. That's what my Honda did anway, don't have an a/f gauge on my A4.

I ran a wideband O2 on my GSR while on the dyno, that can give much more accurate results...

Thoughts?

FB

CharlieGSanD

i got the Greddy A/F Guage & o2 sensor setup, supposedly the o2 sensor they provide is accurate across a wider range so while im shure its not exact, i think its pretty much in the ballpark, but i cant say for shure.....

i does have the flicker @ idle going from stoich, lean, stoich, lean & then after a few (30) seconds it drops to 9-1 & slowly climbs back up to stoich

id really like to run this thing with a true wideband once as it has a "correction" mode wich allows it to be tuned with a wideband to be even more accurate