Thread: Rovergauge tuning

Howdy grimace, good fun setting up the sensors.
I'm interested to hear how you go
On rovergauge with a green tune installed it blanks the lambda readings,which tells me it sends the signal for open loop to the ecu,ie maf voltage.I'll put up some snapshots to illustrate some time. I imagine you'll likely need a cat tune colour to get it reading the sensors.

Here's a comparison between how rovergauge sees the different tune resistors,tune 5 is white,tune 2 is green.

Now what is really strange is on my tune I do/did get the fuel trim displays, they are just locked at zero. Which you'd expect with no O2 sensors. Unfortunately rovergauge is on a laptop currently busy with other tasks but I'll check for screenshots later.

My saga started here: http://www.aulro.com/afvb/2037527-post44.html
Mine was originally on tune 2 (post 48 I write that it was showing fuel trims while on this map).
I swapped to tune 1 and it leaned out a little more.

Howdy,Just been reading a thread a couple of years back that discussed MAF servicibilty and how to tell if your's is good/bad .
Air Flow Meter Supplier
Cockie55 talks of how you need to look at the MAF airflow voltage to see if the ecu is getting valid info from our maf to enable it to set the right mixture for a good idle.
I have been running my 14cux 3.9 classic range rover with precat o2 sensors(cats removed) and have found the idle to be slightly lumpy,feels and sounds like its missing very slightly,no biggie,just enough to wonder why?

As a comparison,i changed to a green tune resistor, yesterday to compare, set the co-trim to 1.25 volts and the idle is much smoother,powers better off the line too.

My reason for this was to see if my maf is working right and may have been causing that miss idle,as the "airflow signal voltage" is lower than i gather it should be at 1.4 volts at idle,where it should be up near 1.7 for a 3.9 litre v8.
This is depicted on the maf reading from snapshots on rovergauge where
28% equals my 1.4 volts,where i gather it should be up at 1.7 (32%)

Any experiences here? Does this mean my maf is on the way out,or just wont translate the correct mixture mapping for the ecu by under reading the voltage?








As an aside .In the top picture, the idle bypass position is down at zero,the car starts cold up at about 23% but slowly drops away to 2-5% then if you adjust the base idle to give a good idle 650-700rpm,it is nearly closed,or showing close to zero on the scale.

The only way to get it back mid scale,ie: recommended range 30-40% at idle,is to wind the base idle closed to restrict the airflow meaning a too low idle of around 500..
This lends me to believe there is an air leak around the plenum area somewhere as the stepper motor must be closing right up to compensate for extraneous air from somewhere,,


Maddening!! as i've removed all hoses,checked them,none missing,none split,removed the plenum,hylomar sealed it back,the only thing i havent done is the throttle plate setting,but seems to seat close to closed or .05mm on release of the throttle springs,had a good look and cleaned it up while plenum was off.Not really sure where else to look,done all the checks for air leaking,carb cleaner etc,seems fine??

This also could have been a additional cause for the lumpy idle running the white resistor tune cat map,not such a problem with the green tune currently,maybe open loop is more forgiving,but it means the stepper motor doesnt have much leeway to adjust currently,,
Once again any thoughts appreciated,cheers westy

Have you checked how clean the MAF wire is? I didn't ever measure voltages before/after on my japanese cars, but they always ran better following a MAF clean.

Also keep in mind the "natural variability" of english electronics.

Have you seen any change in RoverGuage with the different MAF adjustments? I did my remap back in July when the air was cool. Now we're warmer I've had it stall out at idle a few times. So I may need to revisit that.

Regarding the stepper motor. Did you set the base idle to ~800rpm while warm idling with the stepper air supply blocked off?