car: 84 SE

so i got myself an air/fuel gauge for 5 bucks, couldn't beat the price.. so i hooked it up according to the instructions, and it works at idle just fine.. but after going through the gears and deaccelerating, once i get going again it starts bouncing from ideal/rich to super lean... but if i let off and let it idle, it reads fine.. could the o2 sensor have anything to do with it? it's a bosch universal.. and the gauge is a sunpro.. thanks.

-UsD

 

nobody?

 

That is normal. You got it hooked into your harness with your ECU, right?

 

Yeah, theyre notorious for not working worth a damn. Thats why everyone who cares usues a wide band O2 sensor and meter.

~T.J.

 

Actually, I had one on my Z for awhile. I thought I hooked it up wrong too, but it is written in the directions someplace. You need a seperate o2 sensor, or some kind of OP amp circuit if you want it "proper", otherwise your ECU "takes over" the signal. I don't know the electronics exactly, but the ECU is causing it.
Someone told me that it is the ECU constantly trying to adjust the mixture..

 

It's normal if you're getting the signal from the ECU.

It's known as the "closed loop" of the ECU trying to maintain best fuel economy.

Don't worry about it - as long it's on the "green" side when your're at WOT, then you're good to go.