Are Wide Band O2 Sensors Affected By 100LL

[airguy]

Originally Posted by lr172

Has this approach worked for you in extending the sensor life, compared to the numbers Ross is suggesting?

I can't speak to the extension of the sensor life because I've only been running it 122 hours with this set up since installation in March of this year - but I've had zero problems with the oxygen sensor setup for those 122 hours and 6 months so far.

Originally Posted by David Carter

Greg - Can you please post details on your delay timer circuit? I have a Ballenger AFR gauge with NTK wideband sensor in my plane, but it is wired to come on with the master. I'd like to change to your approach of delaying the sensor start.

Thanks!

Here is the device I purchased for this purpose - it weighs only a few grams, can be programmed literally hundreds of ways, and can handle the electrical load of the AFR sensor. I have mine drawing power off the same switch that energizes my SDS computer, and then it looks at the starter solenoid for voltage (from cranking the engine), then waits 30 seconds (you can set whatever delay you like) and then applies power to the AFR sensor. They have 5 amp and 10 amp versions to fit your needs.

https://www.amazon.com/Miniature-cyc...t-items&sr=1-1

[David Carter]

This article quotes Klaus Savier (Lightspeed founder), as saying:

"I thought about installing a lambda gauge in my airplane many years ago, but I was told they wouldn’t work with leaded avgas, so I didn’t question it, and I didn’t try. Finally, I decided to see for myself. I’ve been flying with lambda gauges in my two airplanes now for a combined 800 hours. I only had one probe go bad and that happened early, when there was a lot of rich operation."

The article goes on to say:

the lead fouling caused his first lambda probe to fail. But that problem hasn’t recurred, primarily because the information the gauge provides allows him to run his engine far leaner—and that keeps lead deposits from building up.

https://www.aopa.org/news-and-media/.../pe-lean-on-me

[1001001]

I edited my post above to reflect the fact that my understanding of the O2 sensor/engine startup sequence was originally incorrect. Hopefully that will prevent confusion in the future. Thanks for the correct info!

[David Carter]

This is from the manual for the Ballenger AFR gauge that I have in my plane. I'm using the NTK sensor. The manual is available here:https://www.bmotorsports.com/downloa...0v2_Manual.pdf

I've bolded some portions for emphasis.

The AFR500v2 is widely fuel compatible. Many are listed below:
Gasoline / Petrol (leaded or unleaded)
Alcohol (Methanol)
Ethanol
Compressed Natural Gas (CNG)
Liquefied Petroleum Gas (LPG)
Propane
Many other combustible fuels

Top causes for an error:
1. Bad Sensor due to rich misfiring or backfiring (tuning far too
rich and/or raw fuel hitting the sensor possibly leading to a
cracked ceramic or contaminated ceramic element).
2. Bad Sensor due to having the sensor in the exhaust stream
with no control and no heating which almost immediately foul
a sensor.
3. Bad Sensor due to bad manufacturing or damage in transit or
improper installation (sensor is at the bottom of the pipe, etc).
4. Bad Sensor due to mechanical damage (dropped or hit).
5. Sensor not reading within range due to being too hot or cold
(ie right next to the port or far down the exhaust stream).

How to maximize sensor life
1. Get a baseline tune before installing a sensor. You don’t need the sensor in most cases to get your baseline timing and fuel settings.
2. NEVER leave a sensor in an exhaust unheated (disconnected).
3. Don’t leave the sensor in continuously, only use for tuning and specific monitoring periods.
4. Limit your use of the sensor with leaded, race, or oil mixed fuels. NTK sensors are significantly more durable than Bosch sensors in such environments.
5. Limit time in water cooled exhausts and avoid this where possible.
6. Handle the sensor with extreme care. The sensing element is a delicate ceramic. Rough handling or drops may destroy the sensor.
7. Never exceed 1700F (930C) EGT at the sensor. In high EGT environments, extended bungs such as SNSR-01064/SNSR- 01054 or Heat Sink Bung Extenders such as SNSR-01065 are strongly recommended.

Sensor Installation
Oxygen sensors are sensitive to temperature, pressure and contaminants. A non-ideal sensor installation may dramatically reduce your sensor life.

Ensure that there are no leaks in the exhaust system as this will falsely indicate lean or high air fuel ratio values. The sensor should be installed upstream of any air-injection equipment.

The sensor should not be installed in a pressurized environment and therefore should be installed downstream of any turbochargers or similar systems causing exhaust pressure.

The sensor should be installed upstream of any emissions systems and catalytic converters.

Typically, the oxygen sensor should be installed 1ft to 4ft from the exhaust ports. A sensor that is too close will receive frequent thermal variations, leading to a reduced sensor life. A sensor that is too far away may run too cold and risk condensate leading to reduced sensor life.

The sensor should be installed at least 10˚ above horizontal to avoid condensation and water pooling in the sensing element. Ideally the sensor is installed off vertical between the 10 and 2 clock positions (see Fig 4).

[622BH]

NTK sensors are significantly more durable than Bosch sensors in such environments

Anyone know if the NTK and Bosch (PLX) sensors are directly interchangeable? My question focuses on the cable connector the PLX units have.

I'd hate to have to rewire my system to change over to the NTK...

[David Carter]

Originally Posted by 622BH

Anyone know if the NTK and Bosch (PLX) sensors are directly interchangeable? My question focuses on the cable connector the PLX units have.

From info in the Ballenger manual & on their website, it appears that the cable connector is likely the same, since they list on only one type of cable.

However, you should verify that the device that the sensor is connected to is compatible with both types of sensors. For the Ballenger gauge, there is a jumper setting to change sensors. The NTK & LSU 4.2 use the same setting, but the LSU 4.9 requires a different setting.

The first option is Bosch LSU 4.9 sensor capability. As shipped (unless otherwise specified), this is set for the Bosch LSU 4.2 & NTK Sensors. You must install a red jumper to enable LSU 4.9 ONLY mode.

[walkman]

Originally Posted by David Carter

Greg - Can you please post details on your delay timer circuit? I have a Ballenger AFR gauge with NTK wideband sensor in my plane, but it is wired to come on with the master. I'd like to change to your approach of delaying the sensor start.

Thanks!

Hey David

The way I have mine wired in the Porsche 930 you saw this weekend with the Microsquirt is to have the ECU fuel pump trigger provide ground for the coil of a relay, which powers on the wideband conroller.

I'd do the same thing in the airplane, I'll bet the SDS has exactly that circuit for its use in autos. If not, then I'd use a Hobbes switch to provide a ground for the relay when your oil pressure comes up.

[airguy]

Originally Posted by walkman

I'd do the same thing in the airplane, I'll bet the SDS has exactly that circuit for its use in autos. If not, then I'd use a Hobbes switch to provide a ground for the relay when your oil pressure comes up.

Either would work - I have mine looking for +12 volts on the starter solenoid to indicate cranking, then starting a timer for power.

[N49ex]

I got interested in A/F monitoring for my plane a while ago, and installed a system that has been working flawlessly for a couple hundred hours now. Wrote an extensive article for KitPlanes on it:

https://www.kitplanes.com/adding-dir...io-monitoring/

The key to making this work without the sensor failing prematurely is the right sensor. The one I found is made by NGK and is specifically rated to tolerate some lead. I used the Ballenger system, and modified the display to make it compatible with my panel space.

There are two things to say about this, IMO:
1) After all the back and forth about short sensor life, it CAN be made to work with the right sensor.
2) Having flown with A/F for some time now, let me tell you, it makes setting mixture SO much easier. None of the back and forth with finding the peak EGT, etc. Just remember your two chosen A/F numbers: One for rich of peak operation, one for lean of peak operation, and set your mixture to the number. Glance at your EGT and/or fuel flow to make sure something hasn't gone nuts, and you are all set. It's so nice, I'm reconciled to the possible cost of sensor replacement if and when, but so far still going strong.

Reinhard Metz
N49EX

[David Carter]

Your article inspired me to install the same setup in my plane, and I love it. Thanks also for answering my questions!