Airfuel Gauge

JiN · 03-23-2004

Ok, so I guess I'm just confused, and dont know what to even try next. I hooked up my AF gauge a few days ago, and have gotten different results everytime. The first time, I ran the power wire to the "gauges" fuse, in the fuse box by the clutch pedal. The ground was just a random bolt by my cd player. And the o2 line was run to ecu pin 76. Well that time, my gauge would only light up when I gave it some gas, and it would read completely lean. Wouldnt move at all. So I'm driving down the freeway, let off the accelerator for a second, then put it back on, and the gauge shoots up to stoic, then slides back down to lean. That is the only time it would do anything.

The next time, same setup, only I ran the o2 line to pin 75. Which is also a o2 sensor line, only it says "rear" in most faqs. This time, the gauge read totally rich, and wouldnt move at all. Not when I would rev, or when I did the ghetto little trick with the accelerator.

The last time, I ran the o2 line to pin 76. And the power wire is now moved to a power supply on the ecu. Pin 25. Still grounded the same. Checked to make sure that was sufficient everytime I made a move. Well, this time, the gauge reads totally rich, will not move at all. Same as the last time. Only for some reason, when I use the lock/unlock button on my door panel, the thing flashes for a second. Then goes right back to rich again. So with that said.....WTF??? :blink:

Thanks for the help...

Rickey

Iceman · 03-23-2004

I would recheck your ground. It couldn't hurt.....

FORSFED · 03-23-2004

Maybe your o2 sensor is bad....that'll give you bad readings

Alpine TSi · 03-23-2004

I would pitch the thing in the garbage to avoid the headache you'll get from the damn light blinking back and forth all the time except at WOT when you hook it up right.

But try getting a good clean ground(sharing grounds with components you are drawing power or signal from is a good idea). Also make sure it is good power, I see so many people just tapping fuses and I think that is an awful idea. Get power from your ignition harness or battery and don't forget the fuse. One big tip is make good quality connections, I use tape and soder everytime, but then I am anal and have brainwashed into doing that after three years of mobile electronics install...

Good luck.

npaulseth · 03-24-2004

It's true, A/F gauges are a complete waste of money unless you spend big money and get a wideband. I have had two of them, and they just go back and forth from rich to lean.

tsiawdspeed · 03-24-2004

Dont hook it up to the rear O2 line. Also, I agree with the faulty sensor and the bad ground suggestion.

JustROLLIN · 03-25-2004

The problem with A/F gaues is that you only receive "data" at WOT. The gague goes into closed loop when you are not WOT and jumps around showing you absolutely nothing.

Sidenote: Thats why I sold mine to a kid at RallyFest last year. Kid asked what I wanted for it, he offered me 20 bux. I ripped it out of my car right then and there. LOL

TheBlizzard · 03-25-2004

A/F Gauge=Blinky Blinky thing that does nothing.

Sell it and get a EGT gauge or something.

If you are going to use it anyway, make sure you have a good ground, I know you have already have been told this but check again. Next, how did you tap into the O2 sensor wire on the ECU? You problem could lie there. The pin on the ECU itself could be pulling out and giving you screwed up readings.

First get a volt meter and check how many volts your O2 sensor is giving out. It may be dead and not doing shit, hence the check engine light you have been getting sometimes right?

If you start your car and after like 4 or 5 minutes when your car warm up the check engine light comes on there is a good chance your O2 sensor is either bad or getting bad. The O2 sensor doesn not even start working until it hits 600 degrees.

If none of this applys then fuck it, there really isn't much to them things and the way they work or don't work, however you want to put it.

CRAIG

CRAIG

SuperSleeper · 03-25-2004

Despite the uselessness of the gauge, I don't think Rick really cares. He just wants it to function properly for looks if nothing else. I'm lead to believe the O2 sensor needs to be replaced.

JiN · 03-26-2004

Quote:

Originally posted by illegaLaser@Mar 25 2004, 10:04 PM
Despite the uselessness of the gauge, I don't think Rick really cares. He just wants it to function properly for looks if nothing else.

Thank you very much Dane. Also, thank you too everyone else who gave me any...useful, info. Appreciate it.

Rickey