Slowpoint0

How do I install air/fuel gauge in my 86 trans am lg4,auto,carb
Iv read and been told to find ECM for purple wire connect off gauge.. Black ground "der" ground. And acc wire to radio remote wire?
Is this best way?

Tuned Performance

iTrader: (92)

it make no since to install a wb gauge onto you stock o2s if that is what you are doing. The o2s is in the drivers side exhaust manifold and it is purple. the acc power rob it off the fuse box you may have a open port. The radio remote turn on wire it to turn on a amp.

Slowpoint0

just want the gauge for tuning reasons, a $20 gauge vs a $100+ tuner or computer program

Tuned Performance

iTrader: (92)

a single wire gm o2 sensor has a narrow band if you are fluxuating much from stoichiometric you will be pegged rich or lean on your gauge.

http://www.autometer.com/tech_faq_an...x?sid=1&qid=48

Slowpoint0

so how do i set up air/fuel guage? iv seen them in completly stock lg4 and they seem to work fine?

Tuned Performance

iTrader: (92)

If you still using the stock one for the ccc, Just install a bung in the exhaust and make sure you don't have any leaks around the o2s. If your mounting down stream you will need a heated wb 02.

Slowpoint0

ok thanks

Tuned Performance

iTrader: (92)

what do the install instructions state for the $20 a/f gauge ?

Slowpoint0

it says connect the purple wire from the gauge to the o2 signal wire at the ecm piggy back it, ground just ground and find a remote wire for the acc wire from the gauge

Slowpoint0

i had one in my 98 dodge ram fuel injected but worked fine

ASE doc

The narrow band O2 only reads 14:1-15:1. This is all wrong for a performance application in the first place since you need to be down around 10:1 - 12:1 to make power. I don't see an air/fuel gauge even working with a narrow band O2 sensor. The gauges I've seen run on 1-5V and need to be connected via a controller that converts the wideband O2's varying current signal to the 1-5V signal for the gauge. If someone was running an air fuel gauge in a stock application, they would have to be running a wide band O2 in a seperate bung from the EFI system's narrow band O2 because the gauge won't even read the narrow band O2. Plus, the O2 circuit is such low voltage that tapping into it with a gauge would throw off the reading to the ECM and cause the car's ECM to have issues.

Edit: I suppose some aftermarket supplier may have come up with such a system that taps into the stock O2 sensor circuit. Would be surprised though if it doesn't affect normal system operation.

Slowpoint0

i get what your saying, its a sunpro gauge narrow band that just basic reads the current through the o2 sensor no new bung or sensor.

ASE doc

I believe you. I guess I've seen these on stock vehicles. Ive installed AF meters in performance vehicles either with carbs or tunable EFI. These were wideband meters that allowed us to monitor the full sweep of the air fuel ratio and is helpful in tuning fuel mixture.

Slowpoint0

my goal is to get this running on idle in the 14.7 range its all stock except cat back..

ASE doc

14.7 is stoichiometry. The engine management system should do that on its own. Of course, you'll be able to see this with the gauge.

Slowpoint0

my car is carb not fuel injected, it wasnt running when i got it, i know its rich you can smell it and it dumps fuel, i just want the extra help tuning it close enough is ok

ASE doc

Still, 86 computer command controlled. It uses the feedback carburetor with mixture control solenoid and O2 sensor. In closed loop, it should run stoich. Diagnosing and performing emmisions repairs on these cars, I find a scan tool more useful than anything else. Viewing MC solenoid frequency is how we know the system is working and that the solenoid stops and idle mixture screws are set correctly. The settings are made at idle and at 2,500 rpm in closed loop which means the engine has to be run at 2,500 rpm until closed loop is achieved. Then it will stay in closed loop for a bit until the O2 sensor cools down.

Slowpoint0

gotcha, ill look into getting scan tool also thanks for the help