The V8 Owners Forum -

Hi,

I'm in the process of fitting a Hotwire injection system to my 3.5 Rover V8 engine and intend to fit 2 Lambda probes into my exhaust downpipes.
I know they need to be the 3 wire Titania type, but the cheapest I can find is £80 each.
Does anyone know of a cheaper alternative, or a totally different make of car that have them fitted that will work with the Hotwire system?

Any help would be great.
Thanks,
Dave

I wonder if the hotwire actually reacts to different signals from the two sensors - or just averages them? I suspect the latter.

If so, you could fit a single wideband set - which will be useful if you ever change to MegaSquirt etc - and use the narrowband output. It could also give you a readout of the actual AFR at the same time.

V8RoverDave wrote:Hi,

I'm in the process of fitting a Hotwire injection system to my 3.5 Rover V8 engine and intend to fit 2 Lambda probes into my exhaust downpipes.
I know they need to be the 3 wire Titania type, but the cheapest I can find is £80 each.
Does anyone know of a cheaper alternative, or a totally different make of car that have them fitted that will work with the Hotwire system?

Any help would be great.
Thanks,
Dave

Are you sure they are the expensive type ?

And Lambda sensors arent strictly speaking necessary

How old is your car - does it have or require CATs for the MOT?
If not why not change the tune resistor for a non-cat map and omit the lambdas completely.

Also I believe the hotwire lambdas are variable resistance not voltage -Therefore I'm not sure if you can use the narrowband emulation output on a wideband..

http://www.picoauto.com/applications/lambda-sensor.html

Thanks Chaps for your replies,

I hadn't thought about it averging the probe inputs, good point. But I'm not sure what you mean by wideband and narrowband?

I realise it could run without a probe but I thought the system would run better with the Lambda feedback.

The car doesn't have CATs, but again I was on the understanding that if it has a tune resistor then it will run a standard fuel map, which won't let the engine run as well and fuel consumption will be up. But again I'm not sure on this?

Thanks, Dave

V8RoverDave wrote:Thanks Chaps for your replies,

I hadn't thought about it averging the probe inputs, good point. But I'm not sure what you mean by wideband and narrowband?

I realise it could run without a probe but I thought the system would run better with the Lambda feedback.

The car doesn't have CATs, but again I was on the understanding that if it has a tune resistor then it will run a standard fuel map, which won't let the engine run as well and fuel consumption will be up. But again I'm not sure on this?

Thanks, Dave

Do you know what tune resistor (there's more than one) - a photo or measure it's resistance with a Digital meter

Hi Eliot, I wasn't looking to go down the tune resistor route, unless you think it won't make much difference to the running with one fitted.

Dave