hi. I've got a S5 Jspec motor in my car. S4 computer and stuff. I've also got a A/F ratio gauge from summitracing, just to let me know if its going to blow up. also, I'm running a walbro fuel pump, and I cleaned the stock S4 TII injectors before I put them back in.

anyway, I've just started driving the car again(after the motor swap), and I've never seen the A/F gauge go more than 1 bar richer than stoich.

the instructions that came with the gauge say that all or most of the bars should be lit under full accel, but I'm barely above, or at stoich. this is much to lean, no? and it shows the same under partial throttle, and goes full lean when off the throttle...which is normal.

I'm just a little concerned, and don't want to get to lean and detonate.

 

those a/f gauges are worthless, you cannot tune with them my n/a does the same with a crappy auto meter one

 

Yeah... that uses your stock 1V range O2 sensor... basicly its good to see if your car is actually injecting fuel, thats ABOUT it. By NO MEANS should you rely on that to tell you your A/F ratios... get either a wideband or EGT gauge.

Speaking of EGT gauges... would it be easier to tune an AFC with the EGT or Wideband? Don't want to dyno tune it... want to get used to tuning on the road, as temps change Optimum tuning all year 'round. (Supercharging my 6port)

 

well I wasn't trying to tune it or anything with the A/F gauge, and I know they don't show much, but if its showing the same A/F ratio as at partial throttle, somethings wrong, right? even if its not running that lean, then maybe its just pretty rich under partial throttle?

 

Stop threadjacking!

It's easier to tune the S-AFC with a wide-band.


-Ted

 

The narrow AFR gauge isn't reliable enough to give you resolution to answer your question.
A bad ground could cause you to read leaner.

Are you reading the gauge during the day or at night with the headlights on?
You ever notice the AFR gauge drops when you turn on the headlights?

Why don't you pull the spark plugs to see if they are "white"?

Seriously, we can't give you an answer, because your AFR gauge is not capable of telling you much.


-Ted

 

okay. that helps me understand a little better. plus, my car is failing emissions so badly, and sucking down so much gas, it can't possibly be running lean.

thanks

 

Uh, you said you were having problems with the engine running lean at WOT?
What does it have to do with emissions?
As far as I know, no one runs emissions at WOT?


-Ted

 

oh, I was just saying that I don't think its really running lean, since its running WAAAAAY rich at partial throttle.....

crap, I don't even know what I'm saying anymore. delete this thread.