i recently installed an air/fuel gauge in my 86 n/a an i can't seem to geta reading on the gauge. It does light up the last two bars for a second. I have a new o2 sensor also. The power and ground are connected under the dash an fused in with the fuse box, an the signal wire ti the o2 sensor wire right off my header. Am i connecting to the wrong source?? any info will help.. thanx

 

does it light up with the key in the on posistion but not started? if so you power source isn't hooked up right...

 

I asume the car is fully warmed up? and you are driving / reving it?

 

^^^^^ ummm... yeah, gotta be warmed up.

 

well i started it for about a minute to see, so maybe let it warm up for about 5 mins then?? i have the power wires correct.

 

Mine takes a little while for it to start reading. Take it for a spin.

Jarrett

 

so maybe by the time the temp guage is at regular temp it'll read out then? if so thats understandable

 

I dont usually start reading normal till about 2-3 blocks

 

ok , thats cool, thanx all for the info... peace

 

i have one hooked up as well but mines wierd, the more throttle i give the car the richer it runs acording to the meter. if im driving and holding the throttle at 3000 rpms, it will slowly move on the meter down from stoich to lean. when i get on it, it will move back up to rich (slowly) i need to tune it but could i have other problems (ie bad o2 sensor??) also if i hit my hazard lights, the guage blinks closer to lean on each tick of the hazard light and back up after it turns off. could that just be interferance in the wire? thanks

 

Yep, sounds like the O2 sensor's input wire run is not shielded where it needs to be...

 

Right source, wrong end of the wire. The O2 sensor uses a shielded wire in the engine bay, and it's difficult to tap into it without making the signal wire contact the shield wire, which grounds the signal. You might get lucky, you might not. Next time tap into the ECU end of the wire, which is unshielded.

 

Back from the dead.

 

...........

 

WTF, this is like two years old...wow....

Wonder if he ever got it fixed

It is the fault of the similar threads in the bottom of the post window. You think those threads are so fresh and so clean.....

 

Aagh! Damn noobs! Start a new thread if old ones don't answer your question.

 

lol, isn't that what they are discouraged from doing?

 

oh you didnt know. if there is something similar to someones question but not exactly they should start a new thread even if its old. but when you do that you get flamed to search for old threads to see if it answers your question, which is now answered. basicly your fuxored either way so wtf is the point of the GD forum?

 

We shouldn't have to check the date of evaery post just in case it's been resurrected. At the very least you should mention that it's an old thread so we don't waste our time answering questions that were asked over a year and a half ago by someone who's not even around anymore. It'll just make it a bit less frustrating for those of us who post here a lot.

Anyhow, since you've already posted...You need to be sure the O2 sensor is good before you use an A/F gauge for anything. The best way to check the sensor's health is to head out a flat section of highway and cruise at a steady speed using minimal throttle. After a few seconds the A/F gauge should start oscillating rapidly back and forth over the mid-point of the scale (stoichiometric), indicating the ECU is in closed-loop and using the O2 sensor. If it doesn't do that replace the sensor. In fact considering the car's age you should probably just get a new one anyway. They're pretty cheap.

Where are your wire connections? Ideally they should all be at the ECU. It sounds like you took power from the HAZARD fuse in the fuse box, and when you switch them on the current draw drops the voltage seen at the meter.

 

thanks i appriciate your help (and i failed elementary spelling) i bought the car with the guage hooked up, so i didnt know how it was hooked up and ill look into where its wired and what not. ill definetly have to change the o2 sensor.
oh btw the guage does not move back and forth at a constant rpm. it just sits at one place and if i dont give it any more fuel, it slowly begins to move towards lean.
thanks again