Is my A/F gauge defective, or am i dumb?
 

I intstalled an automete boost and A/F gauge in an A pillar pod today. For the boost, i used the open nipple on the intake mani, ran wires to battery ground and parking light relay for light.

On the A/F gauge (standard LED Autometer), i tapped the green wire with the red stripe on the harnes next to the main underhood fuse box (according to my multimeter, its is 12 volt ignition switched), grounded to battery, and the sensor wire is tapped directly in the to O2 sensor wire, about a foot off the O2 sensor itself.

Problem: The LED first showed stoich, but wouldnt move at all with acceleration. Then the LED's would stay halfway on sometimes, then they were very dim, but never really gave a reading, lean or rich :confused:

Is my gauge defective, or my install? Thanks!

Unless I'm reading retarded, which could very well be the case, your A/F install sounds theoretically matched up fine ... except I have a question. When you say that you grounded these things to the battery, do you really mean you ran a wire all the way to the battery? You do know how ground works, right?

And another thing, why run a power wire all the way to the underhood fuse box when the ignition switch is right there? It makes things so much easier ... and if you don't want to tap directly into the ignition harness wires with a ton of things, a really simple smart trick is to buy a $20 turbo timer harness for it and tap everything into there.

There's an ignition switch right under the damn dash?!?! Awwwww!:mad: I dont really know much about FD's specifically, but boost gauges and A/F gauges are pretty much the same install in most cars. Power, ground, and O2 sensor splice.

I had to run the vacuum line for the boost gauge through the firewall anyways, and there is already a conduit there for my amp power wire anyways, so it was real easy. Where is this ignition switch you speak of? Its hard to find anything under my dash now anways cuz its now so full of wiring and electronics (tv screen AV center, alarm, gauges, TV antennas, PS2 wires, DVD player crap, etc)

So is your vote for a defective gauge then? Has anyone else used the Autometer AF gauge?

They are all defective.

Oh shit, he made fun of DK. Everyone DUCK!:ar:

I did? That's cool, i'm always down for a flame war :fawk:

But before we engage-what do you think of this theory?
I wired the 12V swithed supply for the AF gauge to a harnes that showed 12v when the key was one. But, when running, it looks like maybe that wire isnt giving enough juice for the meter to read right. Does that make sense? And what wire is the ignition wire under the dash? That would be sweeeet :D

Re: Is my A/F gauge defective, or am i dumb?
 

Sounds like your O2 sensor is dying to me. typically a dead O2 sensor will first goto stoich and then to lean condition soon after. Thats why cars with bad O2 sensor always run rich because its telling the ECU it's running lean and needs to dump more fuel.

Steve K

Try splicing the big black wire with a yellow stripe going to the ECU. It's been like 2 years since I installed mine, but I think that's the right wire. It's a little thicker than the rest and I'm SURE it was either all black, or with a stripe. Probably with a stripe since all black usually means ground.
~Tom

Sounds like the sensor has had it last day. Steve is correct. I first got a pointless A/F gauge I had the same thing but to be honest they do not tell you a whole lot:(.

-Rikki

that would explain why i'm idling funny and getting approximately 8 mph this tank! :eek:

You will find that a standard A/F gauge does not read RICH conditions at all. It is good for idle and stoich. If you try to tune with that you will pop or come very close. Most A/F gauges read 12:1 so if anyone tunes to that they should be shot unless it is done on a high quality race fuel. If I were you I would get a 5 wire lamba sensor and a wide band and tune to 11:2.1 and nothing more.

Just my take

i also vote for the O2 wire off of the ecu. i had the exact same results when i tapped into the o2 wire itself. it is insulated, and very hard to get a good connection....

louis

so this wire is the one going directly into the ECU itself? Black with a yellow stripe? There's 4 plugs total going into the ECU-which one?

WOW that is slow. I bet people honk.

black with yello stripe does nothing. :doh:

I think he meant 8 mpg.... not 8 mph

What do you mean that it doesn't read Rich, is it just that it never reads a 'true' rich no matter what the LED meter on the A/F gauge reads?

Can you use a WB-O2 with the A/F meter to get accurate readings for tuning?

I just wired a 12VDC relay into the power wire for the radio so I have a point to wire to the ignition switched 12vdc. Works nice, don't have to get into the dash (other than behind the radio), costs about $2.50 at radioshack


On another note, does it help at all to clean the tip of the O2 sensor? I figure it wouldn't unless the tip was gunked up, but I didn't know if anyone has any other experience....

That was funny as hell! :bigthumb:

Back to the topic, I've never liked autometer gauges but you need to find out what LED's are what ratio. And go ahead and replace the O2.

get on a wideband, that being said, the stock O2 sensor and a/f ratio gauge will only work (haha, i would not even consider this really working) at WOT.

good luck

This may be a dumb question, but can a multiwire wideband O2 sensor be made to work with the stock ECU, or even the PFC? I imagine you'd still need a controller for the wideband, but could you pick off a signal wire from the sensor or controller to keep the ECU happy?

Thanks,