Installing Mileage Calculating Computer

Okay, I am planning on designing a microcomputer for my alero with a LCD display to display fuel economy and stuff like that. I'm sure everyone has seen these before they are in Grand Prix's and yeah alot of higher end cars. And well I WANT ONE.

So what I was wondering if anyone could tell me a way I could read the fuel pump. Like how does it take the signal for how much fuel to send?

Is it an analog signal from the computer in the car or a digital frequency. Any help on this would be super.

Also how much fuel is pumped based on that signal.

Yeah this is my final project for my computer engineering technologist Diploma. Any help would be super. If I get this working I'd gladly show anyone else who wants one how to make it.

Thanx for any help in advance

It's an analog signal, but how they convert that to a digital reading and calculate that based on your average MPG and current speed, (something else you'll need to do) I don't know.

Might wanna ask a GM engineer big shooter, because I don't think thats something anybody is able or willing to do.

You need to calculated, pulse width at the injectors, you need to know pressure in the fuel rail. If you know those things and you know the flow of fuel through the injectors then you can calculate that.

That is a super high level veiw of how to do it.

So is there any set like formula or way to find that formula then based on that analog signal as to how many litres are pumped per second or such.


Because thats really all I need then to do the calculations. Cause after that I would just need wheel speed.


and how would I go about asking a "GM engineer big shooter" about this? is there an email at GM i could write to?

No, no there isnt.. sorry I was being sarcastic, because it's just not something you're going to be able to tie into your home-built carputer...

Home built computer? not really it's a 89C54 Microcontroller. and yes it is possible. lol

It can and will work I was just hoping someone here would have the answer to my question. ohwell Maybe I'll try the emailing GM and see what they can tell me

You're probably better of getting info from the source. I'll see what I can dig up.