Thread: Rovergauge tuning

I can't recall the colours, but you'll want to run the tune that is for O2 sensors but not cats.
The cat tune is richer to heat up the cats.

For the idle you need to set the air-flow via the base idle screw (with the stepper closed). If it's having running issues there then it's the mixture off. Mine was running far too rich and idle and kept getting swamped. Nothing on the MAF screw would make any difference. But leaning it out a point at idle (from memory I think was 10.5:1, now around 11.5:1) made it easier to start and rock solid. It hasn't stalled out since.

You can use rover gauge to wind the stepper in (or watch it wind itself closed when you apply some throttle) then simply unplug it. This is in the blocked position so you can then set idle at 800rpm on the rovergauge screen with the throttle set screw. From there the stepper looks after itself.
Remember to plug the stepper back in after.

Do you have a wind band O2 setup? I bought the innovate motorsports one and wired it in on a cigarette lighter plug with a temporary socket on the tail of the exhaust. It works well and the job would have been impossible without it.

Gidday Dougal,Thats the thing really,there is no tune resistor for an o2 sensors only vehicle,its cat or non cat,but subsequently have seen the tvr tune lads run this setup so will keep the white one in the car.
Yes,did the base idle a while back,but it's target of 700 rpm meant the base idle screw was way set too rich,and have found utilizing the o2 sensors and rovergauge i get a much cleaner idle,by fine tuning to center(best combustion ratio) the lambda readings via rovergauge with a warm engine.
I'll definitely look to get a co2 sniffer for sure.cheers Westy

Originally Posted by westy1

Gidday Dougal,Thats the thing really,there is no tune resistor for an o2 sensors only vehicle,its cat or non cat,but subsequently have seen the tvr tune lads run this setup so will keep the white one in the car.
Yes,did the base idle a while back,but it's target of 700 rpm meant the base idle screw was way set too rich,and have found utilizing the o2 sensors and rovergauge i get a much cleaner idle,by fine tuning to center(best combustion ratio) the lambda readings via rovergauge with a warm engine.
I'll definitely look to get a co2 sniffer for sure.cheers Westy

Isn't the green tune resistor for O2 sensors but no cats? There is a different tune resistor again (red) for no O2 sensors and no cats. which is completely open loop.

You're dead right that without remapping there is no way to get both the correct idle speed and the correct idle mix. You have to compromise one for the other.

I wish that was the case,unfortunately they're either one or the other,here's an excerpt from v8i tuning site.
"A Green tune resistor (green referring to the color of the wires) will always give a non-cat tune, and White is always a cat tune. By the way, the default (Limp Home) tune is a cat map, so this usually makes a non-cat car run very rich."

All the tvr guys run white,like mine with cats gone,lambda sensors still controlling idle and running input to the ecu for better economy.
So after a bit of research,will stick with this as the lambdas are doing their thing

Originally Posted by westy1

I wish that was the case,unfortunately they're either one or the other,here's an excerpt from v8i tuning site.
"A Green tune resistor (green referring to the color of the wires) will always give a non-cat tune, and White is always a cat tune. By the way, the default (Limp Home) tune is a cat map, so this usually makes a non-cat car run very rich."

All the tvr guys run white,like mine with cats gone,lambda sensors still controlling idle and running input to the ecu for better economy.
So after a bit of research,will stick with this as the lambdas are doing their thing

Remember the guys writing the cat/no-cat thing have likely never come across a 14CUX without O2 sensors.

These are the physical variations.

O2 sensors and Cats (various maps for various locations).
O2 sensors and no cats.
No O2 sensors and no cats. (Australian and Saudi)

These are the tune resistors:
White 3900 Ohms USA and European vehicles with catalytic converters
Green 470 Ohms UK and European vehicles without catalytic converters
Yellow 910 Ohms Saudi vehicles (without catalytic converters.)
Red 180 Ohms Australia and the rest of the world.

White is for O2 sensors and cats.
Green is for O2 sensors and no cats.
Yellow is no O2 sensors and no cats.
Red is for no O2 sensors and no cats.

You want a green. It is the only option that fits with running O2 sensors but not running cat converters.

The limp home map is editable with tunerpro just like all the others. Since I run open-loop I have edited my limp-mode map to be the same as my running map.
So I can limp home at normal speeds.

BTW the cats are passive and have no feedback to the ECU. So you can run a cat map and edit it to run the AF ratios you require and the ECU won't know the difference.
The only part the ECU actually cares about is the presence of O2 sensors. Because they give feedback.

As Dougal has suggested I am current placing o2 sensor into a 1991 classic with no cats and I have a Green tune resistor as part of the kit.

Very interesting reading your other observations Westy.

I'll be setting my MAF trim to approx 1.3V as a start point, but will take all your observations into consideration.

I have another issue that you and other may be able to assist me with. I will start a new thread for this so as not to hijack!


Cheers
Grimace

As far as I was aware anything with o2 sensors had to run a cat map,but have never heard of a model with solely with o2 sensors and no cats.i wonder which market they were sold in.
The vehicles ecu only recognises the 4 tune resistors to tell which fuel map to use.
If there are vehicles with solely o2 sensors it would have to run a cat map,ie yellow or white as the green uses maf voltage open loop,I've just been exchanging tune resistors to test this.

Originally Posted by westy1

As far as I was aware anything with o2 sensors had to run a cat map,but have never heard of a model with solely with o2 sensors and no cats.i wonder which market they were sold in.
The vehicles ecu only recognises the 4 tune resistors to tell which fuel map to use.
If there are vehicles with solely o2 sensors it would have to run a cat map,ie yellow or white as the green uses maf voltage open loop,I've just been exchanging tune resistors to test this.

So what does your soft-dash have? O2 sensors with no cats?

O2 sensors don't force you to run a cat at all. The only difference really is how rich or not the map is set and that can be changed.
But all versions will go open loop on full throttle and cold idle where they only use the MAF.

Once you remap it having a cat or not doesn't matter. It's only having O2 sensors or not.