Thread: Fuel economy 3.9 with O2 sensors

Bummer.
Ah well, all good things come to those who wait.
AFAIK they shipped mine really quickly. Its by far the cheapest source. I do not know how they do it.
Regards Philip A

I agree Philip. Much cheaper than anywhere else.

According to the email from USPS they are still in Miami.

probably just adding clutter to the thread and has possibly been posted allready on the forum but this site's great

Rover 14CUX Hot Wire Mass Flow EFI: Service and Troubleshooting

I am having LPG fitted to my 94 Rangie in a month and the LPG system uses an o2 sensor to drive a stepper mottor on the vaporiser to gain economy, so the fellow is going to fit one as it doesn't have one.

Unfortunately the bloke is WRONG in his description of how the oxygen sensors work.
When I tried to helpfully tell him, he became very terse and baically told me I was wrong.

Zirconia Oxygen Sensors provide a fluctuating voltage output between 0.50V and 1.00V. Titania sensors don't create a voltage signal - instead they provide a resistance signal between about 20 kilohm (for a lean mixture) and about 1 kilohm (for a rich mixture). The Rover 14CUX ECU provides the sensors a low-current 5 volt supply and measures the resulting voltage drop across the sensors. So, if you measure DC voltage across the Oxygen Sensors while the vehicle is running (by connecting a voltmeter between terminal 4 and terminals 23 and 24 respectively) you should expect to see voltage readings that vary between 0.50V and 1.00V. Very interestingly, the voltage reading will look similar to what you'd see with zirconia Oxygen Sensors. There's a subtle difference, however. On a Rover 14CUX vehicle, a 0 volt reading means "lean" and a 1 volt reading means "rich", which is the reverse of what you'd expect on most other vehicles.

Both of these statements are wrong and could mislead anyone who is using the info to tune a car and fit sensors.
On a Range Rover the sensor voltage ( and heater) feed is 12v from the fuel pump relay.
AFAIK on all cars with Zirconia or Titania "narrow band" sensors "0" is lean and 1 volt is rich. Wide band sensors are the opposite. when I pointed this out he referred me to Wikipaedia!!!! LOL
Certainly it is true of all Bosch Zirconia sensors as I have read them with both a voltmeter and the Jaycar kit.

I sent him the factory wiring diagram, but no result I am afraid.

So I wonder about some of the other info, although most of it looks factual descriptions of components.
Regards Philip A

Originally Posted by PhilipA

AFAIK on all cars with Zirconia or Titania "narrow band" sensors "0" is lean and 1 volt is rich. Wide band sensors are the opposite. when I pointed this out he referred me to Wikipaedia!!!! LOL

Just go into Wikipaedia and change it anyone can do it easy as.

Then send him the link back saying that he is wrong

Matt.

Originally Posted by Utemad

Still waiting on the sensors....ordered on 11 April and just got confirmation that the package has been sent. Only took them 10 days to send it!
They were paid immediately (Buy it now) by credit card.

The sensors were just delivered to my door
11 business days.

Now to organise their fitting.

If you need any help just PM me.
Regards Philip A

Originally Posted by Utemad

The sensors were just delivered to my door
11 business days.

Now to organise their fitting.

Let us know if they help lower the fuel consumption?

The Australian 4WD Action magazine has a good article on improving 3.5/3.9 Rover V8 fuel consumption. All done by Bruce Davis in Sydney.
I noted he has a couple of recommendations on this site, already.

Cheers,
Ron