Rover Gauge Advice

[Jammez]

Hi Folks

I'm not a TVR owner but this seems like the forum with the most experience of Rover Gauge so hopefully you can help1

I have a Range Rover classic with a newly rebuilt 3.9v8 which I'm now trying to get running properly.

I've got rovergauge set up and all working correctly but what I now need is some info on what expected readings ect I should be seeing on the software.

Is there any documentation available that gives an overview of expected readings for a 94 3.9?

Picture of shiny engine attached for no other reason than it looks shiny!

Cheers

James

[Harveybw]

Try the website below, I believe the chap who updates it is Blitzracing on here, and really knows his stuff. I hope he doesn't mind the direct link.

http://www.g33.co.uk/pages/technical_fuel_injectio...

I'd also have a look around the forum pages as there is a lot of what to expect from the software on here. I am guessing with yours, you would be after similar readings to a Chimaera 400, I don't know if other Chim variants change in terms of readings etc but I find my car mirrors that of a Range Rover running 14CUX so should be ok. Don't blame me if its wrong though!!!

[blitzracing]

I supply full manuals with the cable or is this a home made one?

Edited by blitzracing on Saturday 8th June 20:24

[Jammez]

Hi Mark

The cable is from yourself and I do have the doc you attached in your post. I should have been a little more specific with my original post, the fuel map table is the area I'm keen to understand more on what it means and what readings I should be seeing.

Sorry if it's a basic question but I'm more nuts & bolts with cars & using this kid of stuff is new to me so keen to learn!

Cheers

James

[blitzracing]

The map goes along RPM the top, and engine load vertically. The engine load is derived from the AFM reading, so under light load the active fuel load point will be near the top of the table and will drop vertically as the AFM output goes up. It stands to reason if the engine is drawing more air, then its likely that the RPM is going up as well as you open the throttle, so on the whole the load points will travel from top left to bottom right diagonally as the engine accelerates. Ideally a good map will reach the bottom right corner under full load and RPM. The values displayed in the load table are in hexadecimal by default- where FF equals the peak fuel per engine cycle, or this is 255 in decimal as you have 255 available steps in your fuel amount. This value relates to how long you have the injectors open.. If you prefer to work in decimal, just google hex to decimal converter.

You will reach other areas of the map on the over run, where the RPM is still high, but the throttle is shut, so the AFM output is low, so overrun is likely to be in the top two rows of the table. You may notice the fuel load value will be less than FF or 255 towards bottom right corner- ie at peak load and peak RPM. This would seem counter intuitive as you would think you need peak fuel, but what happens is the engines volumetic efficiency drops as the engine struggles to fill the cylinders at high piston velocities, so it only draws in what the valves and inlet tract allow. This means you have to reduce the fuel per engine cycle to keep the mixture correct. The engine will still produce peak power as you have more cycles per second as the rpm rises, even if each cycle has slightly less fuel.

hope this helps

[Jammez]

Thanks Mark, that’s really helpfully in understanding the table. At the moment the values at idle are jumping about which doesn’t seem right to me. I’ve been sorting out various issues to settle the idea down which I’ve done now but the fuel table seems erratic.

Any thoughts?

[blitzracing]

You wont find it rock solid at idle, it does jump a around a bit, especially if you have tuned the engine and the airflow through the AFM is more ragged.

[srdtvr]

Hi I've got a pre-serp Chimaera which is running rich which I know there could be many reasons why, I've plugged in my Rover Gauge and not really sure what I'm looking for but my battery went flat almost immediately.
The alternator is quite new and was putting out 12.3 v at idle is this a Rover Gauge issue or just a coincidence and I need a new battery?
With regard to the Rover Gauge read out, the only thing that looked wrong were the Lambda sensors the green indicator bar on screen just stayed in the middle with no movement - any help would be welcomed thanks
Steve

[blitzracing]

The probes need to be hot to work, this should take about 30 seconds after stating the engine if the probe heaters are working. Also try lifting the idle a bit, sometimes the stop moving if just left ticking over. You should get a fault code if the probes are faulty. What is the long term trim doing?

[Belle427]

srdtvr said:

Hi I've got a pre-serp Chimaera which is running rich which I know there could be many reasons why, I've plugged in my Rover Gauge and not really sure what I'm looking for but my battery went flat almost immediately.
The alternator is quite new and was putting out 12.3 v at idle is this a Rover Gauge issue or just a coincidence and I need a new battery?
With regard to the Rover Gauge read out, the only thing that looked wrong were the Lambda sensors the green indicator bar on screen just stayed in the middle with no movement - any help would be welcomed thanks
Steve

Not sure what tests you carried out but I'd expect to see closer to 14 volts at the battery.
If you still have the 100 amp fuse on the chassis underneath its worth checking it.

[Steve_D]

Your first job is to resolve your charging problem. As said you should be up around 14V whilst running.
Your low voltage could also be messing your engine running as many sensors and inputs to the ECU are dependant on known reference voltages.

Steve

[srdtvr]

Thanks Steve I'll do some checks
regards
Steve

[Steve_D]

With engine running test voltage at the battery. As said should be around 14V.
If not then try testing at the back of the alternator. If you don't have 14ish then the alternator is duff. If you do then you need to replace the 100amp fuse which lives under the offside engine mount. Don't just look at it you need to remove it. The normal failure mode is not the fuse blowing (which you would see) it is a fracture due to vibration.

Steve