XJ Mods VSB 14

[alexbrown64]

Well, its all systems go. Glen dropped the unit off this afternoon in his 351 XD Falcon. Nice car and nice bloke. We had a good chat about the unit and he run me through some demo's.

I used a 12v power supply in the house and fired her up. Went through a few screens and adjusted a few parameters like fuel tank size etc. The touch screen and menus work well.



The wires i will tap into are at the PCM under the bonnet. The white/orange for the vss, and the white/dark blue for number 1 injector driver.

There are about 5 display screens that you can use. Each one has different information and a slightly different look. Its very easy to scroll between screens.



Once up and running, you have to calibrate the speed in the calibration settings. Once calibrated, the econometer will be in sync with the Jeeps speed. The other calibration is microseconds of injector time open to deliver one litre of fuel. The econometer has a rough figure built into it for injector time. You have to fill your tank, then when you have driven a few hundred kilometers, you refill in the exact same way (and same fuel station/bowser) if possible. The calculation is (econometer reading / real world reading) x microsec/litre. This has to be inputted into the econometer. Once calibrated, the system is accurate within 1% per tank.



No matter how soft or hard you drive, the computer can calculate how many microseconds the injectors were open to burn a litre of fuel, and speed/distance. You then get all the data you need.

So, Tony, i should be able to see in real time what litres/100kms i am getting at any speed. I should easily be able to find the most economical speed to drive at, rpm range etc. Also, any mods i do will show up in the figures.

Not a bad bit of kit. I hope to get it up and running and calibrated within the next week.

Stay tuned for some real interesting info on live XJ fuel usage data.

Cheers,

[alexbrown64]

Spent the day playing with my new fuel economy gauge. I tapped into the VSS and #1 fuel injector wire. I spliced the new input wires in and soldered them. I also used liquid electrical tape to insulate them. I then ran all the wires inside conduit through the firewall to the new gauge.



The gauge was wired up for power by diverting some switched wires that power my stereo.

It took a bunch of time to figure out a non obtrusive mounting point. Made my own brackets and fitted it up where i could operate it, view it and not be obtrusive.



Once fired up, she really showed potential.
The rpm gauge worked spot on straight off the bat. I have to adjust hot idle litres per hour from 3 to 1.8 to get a ball park figure.
Lots of stuff whiring around and will take a while to figure it all out.
Only one area of concern is the built in speedo. I am getting a major bounce in speedo readings. I have talked to the developer and he wants to come down with an oscilloscope to check the input. Now that's customer service!!

Lets hope we can get the one last config problem sorted, and then move on to some real world XJ OBD1 live fuel economy data....

Cheers,

[LuluBelle]

all I can say is Wow Alex
_____ooooo
/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_)

[alexbrown64]

Thanks Mark. It is a nice bit of kit. I had a quick play this morning. I bypassed the speed wire from the ecu, and run a direct wire from the speed sensor at the transfer case. This effectively bypassed my yellow box, which is an electronic speedometer adjuster (you don't have to swap speedo gears).

This worked great, and i now have all functions working properly.

Now it just a case of tidying it all up and starting to set all the parameters so that my readings are accurate. In a few weeks i should be starting to get accurate live mpg figures while driving along.

Cheers,

[alexbrown64]

Trialing the new OBD1 fuel enconometer is going well.
I still need to do final calibrating, but have been driving around on a rough calibration until i do my first major refill. The Distance to Empty gauge works really well and is a good tool in seeing how much range i have left.

On another note, i was asked about the YellowBox speedo calibrators. These connect to your speed sensor and electronically alter the signal to the speedo and computer. Good bit of kit, as you dont need to change speedo gears, and if your having problems with an accurate speedo, this can be infinitely adjusted to give you a perfect readout. I have mine set up in the centre console and use the two buttons to set the speedo to exactly the same as my phones GPS app.



Their made in Australia and can be found here...https://www.yellr.com/

Now that i have my touch screen fuel economy gauge up and running, i can start to tweak different components to see how they effect instant economy. The gauge has an instant lt/100km readout and a kph read out. I can use the same flat stretch of road at 90 kph and watch the instant readout.

I had a list of different things i was going to try, but have discounted most of them after research. The car is tuned perfectly and i am running Ron 91 fuel. I was thinking of going to 95, but the cost far outweighs any benefit.

So i put an order together from RockAuto for a new standard Hayden clutch fan, PCV valve and fuel filter. I also ordered a K&N filter. There are reports on the K&N letting in dust, but if you keep them oiled and grease the edges, then it should be fine for testing.

I have the heavy duty clutch fan, and it is great at keeping the engine nice and cool, but is loud and has a lot of drag. So the experiment will be to run the car on the two separate fans on the same day, same speeds and same road and see if there is much of a difference in cooling and fuel economy. The same will be applied to the air filter. The PCV and fuel filter are just basic maintenance items.

I also have a new NTK O2 sensor i want to fit, but will run the same tests as above.

It will be interesting to see if there are any benefits with the changes. Will report back with findings.

Cheers,

[awg]

Originally Posted by alexbrown64

Trialing the new OBD1 fuel enconometer is going well.

It will be interesting to see if there are any benefits with the changes. Will report back with findings.

Cheers,

it will be interesting although I doubt anything but losing weight or profile will do any good, although I have seen surprising reports on the fans!

I dont know what others do, but I just fill up asap the light comes on and reset the odometer..I usually get 59-63L in, average ~60L per 360km

some points you have already alluded to would be "optimal cruising speed"

"litres per hour at idle with aircon on" ...I estimate this to be as high as 3L

and how far it says you will get on that last 1/4 tank...~70km is the max I have done

[alexbrown64]

The good thing about the new gauge Tony is that it has quite a lot of functions, and once calibrated, will be very accurate.
It actually has a litre per hour readout. So, instantly, i could turn the aircon on and off and see how much the reading goes up or down.
You can also set the fuel tank to any size you like. I have a 125 lt tank, so i have set it to that for my Distance to Empty. But you can give yourself a buffer of 5-10 litres or whatever you like.

You are correct in saying driving style and speed are the biggest factor. Using it yesterday, i could see that driving at 100kph was a lot worse on economy than even 90kph.
Also, accelerating from standing still and getting into a higher gear seems more economical than lugging the gears slowly.

The gauge isn't 100% calibrated yet, as that will be at the next tank refill, but i took some readings last night and today. Last night, after a drive and pulling back in the drive, i got a hot idle L/100 solid reading of 1.8 lt/100. Today, i jumped in the Jeep and did a cold start idle. Instant reading was up around 6 lt/100 then settled down after a few seconds to about 3.6 lt/100.

When i am fully calibrated, i will start writing down some numbers and looking at aircon load, time taken to go into open loop from cold start, lt/100 numbers etc.. as well as all the other data..

Cold idle......in open loop....



Hot idle.... in closed loop....



Cheers,