Autometer A/F install problems - Honda Prelude Forum

j92s · 06-26-2002, 06:46 PM

I hooked it up and it acts like its on crack.

red wire to battery positive
black wire to ground

purple to white wire coming off o2 sensor

it just jumped back and forth between rich and lean.

Thanks for any help. I searched for the answer, but it was all 5g responses

aneurysm · 06-26-2002, 06:52 PM

it will do that for the most part. Honestly, its more for show than absolute accuracy. You know that you've hooked it up right when its goes to all RICH when you first start the motor, also when you hit the gas while driving- its will also go all the way lean when you are moving and let off the gas.

brad

j92s · 06-26-2002, 06:54 PM

so at idle, it bounces around, i mean, this thing looks like there is no rhyme or reason to its bouncing around. I'd say every second, it bounces to both extremeties twice. I believe what you're saying, i just want to be clear about what its doing. Thanks for the quick reply. Im sitting here hitting the refresh button even though its to dark to get back on it tonight

aneurysm · 06-26-2002, 07:14 PM

this is normal. The ECU adjusts the a/f radio to maximize efficiency and minimize emissions, so it continuously adjusts the ratio to do this.

j92s · 06-26-2002, 07:20 PM

sweet, thanks for the info, so when i drive, it will somewhat even out?

Machine Head · 06-26-2002, 07:34 PM

when your car is warmed up it should stay in the orange to green with some fluctation, and go red when your driving and let off the gas. The o2 is a OK hookup but it's easier if you just run it off of the ecu under the passenger foot rest

aneurysm · 06-26-2002, 07:34 PM

no, it will NOT even out....its will always be sweeping and adjusting unless the two things I mentioned are happening:

you let off the gas
you step on the gas

otherwise, the computer is continuously adjusting the ratio....that's just how it is.

brad

j92s · 06-26-2002, 07:38 PM

I think i'll see what happens when i hook it straight into the ECU. Does anyone know which pin off the top of their head? F22 motor...

j92s · 06-26-2002, 07:41 PM

I looked it up, looks like its D14. I think

hypo-si · 06-26-2002, 07:49 PM

Hay.. I got a Autometer Air/Fuel Gauge and mine acts the same, when starting the car it goes to rich, it then sits at rich if the engine is cold, when it warms up it bounces back and fourth..

when driving if you have your foot on the gas, not flooring it, it usually jumps between lean and stoich (usually hangs around stoich - normal cruising), when I floor it it will go across to rich (obviously) if i let off the LED's will go out, then go back and fourth between lean and stoich until I re-apply the gas...

aneurysm is right, I think it is more for looks then anything, but it looks cool

j92s · 06-26-2002, 07:51 PM

greeaat, i was under the impression that i could actually monitor something with this $60 piece of finely tuned equipment. Guess I'll have to settle for 'cool looking'

How did you hook yours up. Im gonna go the ECU route. Much cleaner install. I think its D14, i need to find the ECU section of my HEML manual...

hypo-si · 06-26-2002, 08:46 PM

My bro did it for me so excuse me if I sound like a dill! I aint no mechanic LOL!

as I know I hooked the power wire up to the Accessories wire running out of the ignition, hooked up the other wire to the oxygen sensor.

unsure if there was a ground wire, if there was well you know where to stick that

it seems to react okay.. I have a proper air/fuel gauge in the engine mounted to my FPR (fuel pressure regulator) I guess if you want accurate you get a mechanical gauge and mount that that shows the fuel PSI in analog

blkvteclude · 06-26-2002, 11:08 PM

yea it is not as accurate as you think but a friend of mine has a good one his doesnt jump around all the time and only comes on when the car is warm

Fast&furiuslude · 06-26-2002, 11:52 PM

mines all the way on rich,it sux

j92s · 06-27-2002, 09:59 AM

I found my HELM manual, but cant find a pin diagram for the ECU...Any ideas?

aneurysm · 06-27-2002, 08:55 PM

test for a white wire (I believe) at the ECU
the best way to find it is to test with a multimeter on all of the white wires you see (there's only about 3-4 of them total).

Using the multimeter (NOT A TEST LIGHT!) test the white wires. The o2 sensor wire will range from .025V and 1 volt. If you step on the gas it will go up, let off, it will go down.

brad