Hi guys, about Air/fuel ratios

**yjustin** · 03-31-2006, 03:58 PM

hey guys

I was working on celica with 3sgte swapped engine.
I was installing gauges(boost, air/fuel, oil pressure)

I having problems with air/fuel ratio gauge
When I start the car, the LED lights move for second and goes off, which seems to be the signal voltage problem. I measured the voltage coming out from signal wire(from O2 sensor), it should be 0 ~ 1 volt, and it was showing -0.08, and yes, of course i connected + to signal wire and negative to negative, i also tested the voltage on my 94 celica GTS and I get positive voltage.

would this be O2 sensor problem ?

thanks guys

Justin

**Pineapple** · 03-31-2006, 04:48 PM

O2 sensor doesn't work untill they got heat up to a few hundred degree. Drive around till engine get off cold idle and see. If it take more than 5 min of driving to get it to work, get new sensor. Also if it work and stop working when you idle the car for a while, get new sensor again.
BTW do not use the gauge to tune the engine unless you have a wideband O2 sensor.

**yjustin** · 04-01-2006, 11:31 PM

thanks for the reply.

How can you tell if my o2 sensor is wide band ?
I just got boost gauge, air/fuel, and oil pressure gauges to install .
what do you mean do not use the gauge to tune the engine ?

thanks again~

**Pineapple** · 04-02-2006, 01:01 AM

If you did not buy a wide band, you don't have one.

Some people think they can use the Air/Fuel gauge to tune engine for best Air/Fuel ratio. Fact is, it doesn't give an accurate enough reading for tuning. Basically it just tell you if the O2 sensor is working or not.

**yjustin** · 04-05-2006, 12:14 AM

You know what the funny thing is ? The voltage reading has to be between 0-1 volt. and I get a reading of -0.7 which is funny, and yes i connected the voltemeter in right order.

One more questions is that the vacuum was increased after i installed the boost gauge. Goes down to 20 VAC, what would be the problem ? anybody ?

thanks guys

03-31-2006, 03:58 PM	#1 (permalink)
yjustin Posts: 25 Join Date: Oct 2005 Last On: 03-16-2007 09:52 PM	Hi guys, about Air/fuel ratios hey guys I was working on celica with 3sgte swapped engine. I was installing gauges(boost, air/fuel, oil pressure) I having problems with air/fuel ratio gauge When I start the car, the LED lights move for second and goes off, which seems to be the signal voltage problem. I measured the voltage coming out from signal wire(from O2 sensor), it should be 0 ~ 1 volt, and it was showing -0.08, and yes, of course i connected + to signal wire and negative to negative, i also tested the voltage on my 94 celica GTS and I get positive voltage. would this be O2 sensor problem ? thanks guys Justin

03-31-2006, 04:48 PM	#2 (permalink)
Pineapple Location: Toronto Posts: 4,248 Join Date: Jan 2004 Last On: Today 02:21 PM	O2 sensor doesn't work untill they got heat up to a few hundred degree. Drive around till engine get off cold idle and see. If it take more than 5 min of driving to get it to work, get new sensor. Also if it work and stop working when you idle the car for a while, get new sensor again. BTW do not use the gauge to tune the engine unless you have a wideband O2 sensor. __________________ http://photos.yahoo.com/fredericklaw http://members.rankmyride.com/pineapplelaw

04-02-2006, 01:01 AM	#4 (permalink)
Pineapple Location: Toronto Posts: 4,248 Join Date: Jan 2004 Last On: Today 02:21 PM	If you did not buy a wide band, you don't have one. Some people think they can use the Air/Fuel gauge to tune engine for best Air/Fuel ratio. Fact is, it doesn't give an accurate enough reading for tuning. Basically it just tell you if the O2 sensor is working or not. __________________ http://photos.yahoo.com/fredericklaw http://members.rankmyride.com/pineapplelaw

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04-01-2006, 11:31 PM	#3 (permalink)
yjustin Posts: 25 Join Date: Oct 2005 Last On: 03-16-2007 09:52 PM	thanks for the reply. How can you tell if my o2 sensor is wide band ? I just got boost gauge, air/fuel, and oil pressure gauges to install . what do you mean do not use the gauge to tune the engine ? thanks again~

04-05-2006, 12:14 AM	#5 (permalink)
yjustin Posts: 25 Join Date: Oct 2005 Last On: 03-16-2007 09:52 PM	You know what the funny thing is ? The voltage reading has to be between 0-1 volt. and I get a reading of -0.7 which is funny, and yes i connected the voltemeter in right order. One more questions is that the vacuum was increased after i installed the boost gauge. Goes down to 20 VAC, what would be the problem ? anybody ? thanks guys