I just found out that my fuel is running lean as the RPM increase. I bought a A/F Ratio gauge and was testing it before installing it. I tapped the purple wire to the Green wire from the O2 sensor and the other 2 wires from the Gauge is power and ground of course. When i turn on my car, it automatically shows about 3-4 bars in the stoich area, but leaning towards LEAN rather in the middle or towards rich. When I increased the RPM from the TB, it dropped 1 bar to LEAN. I even tried to boost up the FPR PSI to 50...but I got the same result. What else can it be done?

 

stop relying on a dumb inaccurate a/f gauge.

 

thanks for the information. I"m pretty sure you are educated and designed your own A/F ratio, which you think it's more accurate than the "REAL WORLD" A/F. Anyhow, how do you rely on than? Dreams and hopes?

 

Sorry, but he's right. They're not the most accurate devices.

 

They only tell you if your running "lean" if your mixture is more then 14.7 which in a turbo's case is DANGEROUSLY lean.... so basically if your "crappy" a/f gauge using the stock sensor is hooked up right and you are reading lean on that thing in boost, you ARE running lean, but so lean I would recommend not boosting again at ALL until you resolve your fuel issues... A/F gauges that aren't wideband or use the stock sensor are emergency usefull only, but none-the-less serve their purpose...

 

My friend has the same set up and when he turns on his car, it goes to RICH for 10 seconds until it idle, then back to STOICH. If my car doesn't do that, isn't it's obvious that my car is not delivering fuel right? There gotta be away how we can tell that we are running lean or rich, which the A/F helps it out. As they stated, when you in WOT mode, isn't it supposed to be RICH anyways?

"They only tell you if your running "lean" if your mixture is more then 14.7 which in a turbo's case is DANGEROUSLY lean.... so basically if your "crappy" a/f gauge using the stock sensor is hooked up right and you are reading lean on that thing in boost, you ARE running lean, but so lean I would recommend not boosting again at ALL until you resolve your fuel issues... A/F gauges that aren't wideband or use the stock sensor are emergency usefull only, but none-the-less serve their purpose..."

Can you write that in English? Reading lean on that thing in boost...what thing and what boost? A/F gauges that aren't wideband or use the stock sensor are emergency usefull only...WHAT????? Is that YOUR way of saying it's for emergency use only? Sorry about being a dick, because I'm in College English class so this is probably a best way improving my reading skill....but for real, I didn't get what you meant...but I think I do. Hopefully I can retranslate your thesis.


[Modified by JHO_82, 8:25 AM 10/11/2002]

 

Is your fuel presure dropping of at hifgher rpms?

 

He is talking about if you are running a turbo system and relying on an inaccurate a/f gauge it is very likely you are running very lean. The "regular AF gauges are ver inaccurate. They only give you a ballpark condition. Read your plugs and see how they look or if you are really worried invest the bucks and buya wideband. But first look at your plugs to get an idea of how the car is running.

 

my fuel pressure doesn't drop at higher rpm

 

dude get a digital egt monitor, not an a/f gauge (ridiculously inaccurate)and not a reg egt gauge ( they are waaaaaay slow albeit accurate) ....percy's and compucar make digital egt joints...otherwise ya gonna blow your **** up looking @ bars...

 

For the most part your O2 sensor is made such that it will only tell U if your A/F is more than 14.7:1 or less than 14.7:1. If your A/F is just a little bit less than 14.7 the voltage from the sensor will drop to it's min value, and if your A/F is just a little bit over 14.7:1 it will shoot right up to max voltage. If U were to look at the voltage of the O2 sensor while your can is running in closed loop fule trim mode, U would see the voltage occilating from min to max about 4 times a sec. Your ECU is keeping the A/F right at about 14.7:1, it goes a weeee little over then a weeee little less, and back. Anyway your O2 sensor is NOT a good indication of the A/F but just if it is more or less than 14.7:1

If U want to read the A/F U need a wide band O2 sensor, but replacing the stock type O2 with a wide band would mess up what the ECU is trying to do (keep the A/F optimize). So what ya need is to install a wide band 02 sensor and take it's output to your A/F meter, and also take it's output to a little circuit that would take a reading of anything greater than 14.7:1 and max the voltage to the ECU, and with a readeing of anything less that 14.7:1 send the min value to the ECU. I have no idea if such a circuit exists on the market, but would be fun to build one.. it should work




[Modified by 57STS, 1:42 PM 10/11/2002]