Hello all there. This is my first post in this forum.
I have a 1989 MB car, to which I installed a RD28 6 in line diesel, of 2.8 liters.
It is a naturally aspirated diesel.
I am developing a system for mesuring diesel fuel consumption. As my engine has fuel return flow I installed two fuel sensors.
The idea was to measure diesel consumption in three ways, and validate and calibrate them with each other:
1. Install a couple of fuel sensors on each fuel flow pipes, one on the fuel injector pump pipe and another in the return pipe. Then measure both signals, digitalize them and make the difference to account for the net flow.
2. Measure throttle position and rpm signals and make a model to estimate fuel consumption in relation to these two variables. The specs of the fuel pump are necessary for this method. I already developed the math model.
3. Measure fuel tank curve and the distance of a trip. One can do it always by refuel the tank full after each trip, you would say. No, no. What I am talking about is having a almost "real time" measure of tank. For that, I filled the fuel tank and recorded the digitalized signal of the fuel sender every time it changed. (It proved to change in jumps, approx. every 5 liters of fuel. This is necessary as the fuel tank isn?t linear in capacity).
At the same time, one need a digitalized signal of the distance. Dividing the distance by the liters every minute or so, you will have a measurement of "real time" consumption.
For the digital part of it I am using an Arduino board and a LCD screen.
Please see: http://www.flickr.com/photos/oldbeaver/4116160742/
and : http://www.flickr.com/photos/oldbeaver/4115242131
At present, I am in the phase of getting this to work.
The Arduino Board and the LCD screen are conversing ok.
I have 7 signals already wired to my system.
However, one of the fuel meters are broken, cause no signal is coming out from it.
The second problem I have is the impedance of the voltage dividers that must be used for each signal before entering to the Arduino board, as car signals are always close to 12 volts and Arduino maximum input is 5 volts.
So I am stopped at this point.
Need a lot of time to test suitable impedances for each signal, as I am not electronic (just a forester), cause they may be different. Besides, I need to replace the broken fuel meter.
What I want with this project is to provide a fuel meter system for old diesel engines like mine and many others.
Any ideas or any help?