mileage computer for a carbureted engine

[diesel_john]

dcb,
your fuel pressure is what 0.5 psi maybe, first i thought, graduated cylinder with a stop cock on the bottom. Then i thought an IV drip in the fuel line counted by an electric eye. and magnet on a spoke counted by a sensor.

we are going to need an electronics wiz to jump in here sooner or later and tell us how to divide one signal by another and display the result. that does not give us mpg but it would be a relative number. for comparing driving styles or whatever.

how about a solenoid style fuel pump, they pulse on and off
http://www.facet-purolator.com/solidstate.asp

[dcb]

I really like the drip idea 'cept I'd need like 15000 drips/hour on average.

I just realized, you have a positive displacement pump in your diesel. You can probably make a good guess at fuel consumption based on the throttle position and rpm alone, as long as you leave the smoke screw alone

[personx]

D_J
Where would I find an optical sensor for this kind of project? Is one used on a auto somewere or do you have something else in mind?

[diesel_john]

I just realized, you have a positive displacement pump in your diesel. You can probably make a good guess at fuel consumption based on the throttle position and rpm alone, as long as you leave the smoke screw alone [/QUOTE]

A couple years ago, on the diesel, i mounted a thottle positon sensor on injector pump linkage. so at a given conditions, i can read the resistance change and get a relative number to comparing mods. i test both directions on the same road at 55mph.

[diesel_john]

Originally Posted by dcb

I really like the drip idea 'cept I'd need like 15000 drips/hour on average.

for the bike a flow meter could be sized for the flow with smaller bead and track with closer tolerances.

or maybe a small solenoid pump and regulator to 0.5 psi

[diesel_john]

Originally Posted by personx

D_J
Where would I find an optical sensor for this kind of project? Is one used on a auto somewere or do you have something else in mind?

for sensing an object breaking a white light beam or infared, radio shack for example has several types of light sensing components and emitters.
this one was listed under compoents at the shack
http://www.radioshack.com/product/in...rt&tab=summary

it takes a small handful of these 1 dollar parts to do the whole project from two ac signals in to a voltage out we can read with a multimeter, or with more effort to its own display.

to get just fuel flow per unit time, it would take half the processing. in fact these displays on treadmills and bicycles would do that once we get the right shape signal to input to them. The flow meter is the show stopped IMHO.

i am not knowledgeable enough in electronic to know all the lastest short cuts, there is probably a chip that incorporates all these components in to one piece

[dcb]

There is a rather bulky shortcut to the electronics problem, but it turns it into a programming problem. If you can live with a laptop computer for a display then check out the diy mpg gauge (for fuel injected vehicles). It would be good for prototyping if nothing else and could theoretically be taught to read drips, marbles, throttle position, vehicle speed, whatever.

http://www.gassavers.org/showthread.php?t=4250

[dcb]

Or you could use a supermid ($170) and just figure out how to get the marble signal to look like injector pulses. The RPM displayed would be way off (and possibly the duty cycle), and it is only in metric units currently, but it would be a lot smaller than a laptop.

http://www.greenhybrid.com/discuss/f...-1-t-1-a-3015/

[dremd]

I THINK that there was/ is such a device available from JC Whitney. No Idea how/ if it works.
I'm guessing it is a vac gauge . . .. . .


Edit: Never mind it's just a Vac gauge with some #'s on it
http://www.jcwhitney.com/autoparts/P...002121/c-10101

[diesel_john]

i just found the patent on the flow sensor i had back in the 80's

http://www.freepatentsonline.com/451...o&stemming=off
it failed because the light burned out and the ball dissolved from the unleaded gas. in the drawing it appears more complex than what i remember.
first pic the ZEMCO computer(80's)
i also have the PDF file that i can e-mail.


for any non-ODB MFI, i have a KEL on my truck, from Poland, most $200 in it, just buying one. there is no credit link between here and Poland.
Second pic the KEL economy and trip computer. I have the manual in a word .doc.