Any ideas on how to accurately measure mpg’s on an older car with a carburetor?

[dcb]

Nice!

FYI, my saturn idles at about 0.3 gph. This looks to have a lower limit of about 0.5gph. Not a big deal if you hardly idle, but just fyi. It would be good to see how it tracks on a tank to tank basis.

[TheTestPilot]

the flowsensor has a 1.3mm orifice at the inlet to the paddle wheel ,even though it has a 5/16" hose fitting ,I am hoping adding more sensors will allow it to work with lower flow rates.

As for the speed sensor ,see attatched picture ,it uses the same hall effect sensor I have used to mod the flow sensor .
I have left it unpotted & exposed until I have tested it further.
So far the speed sensor works ok & it's simple (three electronic components & two magnets).

[TheTestPilot]

a better photo of the speed sensor

[gone-ot]

...hey, TestPilot, there's some info about the Flo-Scan™/Space-Kom meter is this earlier posting:

http://ecomodder.com/forum/showthrea...eup-18198.html

[TheTestPilot]

Thanks Old Tele Man
Yes I did see that post. My motivation for the flow sensor was to replace my old Zemco sensor ,that dies about 5 years ago. . I spent enormous amounts of time trying to stop it reading the vapour ,about 15 years ago,I gave up.
At The moment this sensor looks good as far as vapour goes ,it's summer here ,but low temps ,about 28 c ,so still testing.

[Superturnier]

I've had problems with the vapor too. I've tried many different things to prevent the Zemco counting the bubbles. Last summer I took the sensor off the car, as the hot weather + 2hr at highway resulted in a total vapour lock and the engine did not get any fuel.
Then I decided to get an electric fuel pump, Hoping it would solve vapour problems. Maybe I get it installed for next summer.

Are you using this new flow (and speed) sensor with MPGuino?
I would be interested, how have you connected the hall sensors to it?
I quess you need a few electrical components to adapt the signal for MPGino?
Any schematics?

[gone-ot]

...have you considered installing one of the 1970's MoPar "vapor-seporator" fuel filter cans just before the flow-meter unit?

...I'll try to find a picture (below), but it basically was a regular fuel-filter assembly with three pipes: an inlet on bottom and two outlets: one for FUEL to carburetor and one for returning VAPORS to gas tank.

...here's a picture of a HASTINGS GF84 replacement unit:

[Superturnier]

Originally Posted by Old Tele man

...have you considered installing one of the 1970's MoPar "vapor-seporator" fuel filter cans just before the flow-meter unit?

I quess you meant this question for me?

Well, the answer is no, since I never had seen or heard of this kind of separator before.
But I created a system of my own. Since the mechanical fuel pump attached to engine block gets hot, it will make the fuel boil. Especially when the flow is slow. (and I have tried insulating gaskets in between) And the bubbles will expand in both ways.
So I installed the flow sensor before the fuel pump and also put 1 meter of fuel hose and a big fuel filter in front of the sensor to catch the bubbles.
This setup helped to get more accurate readings, but there was also quite big delay in the readings.
But I hope that the electrical fuel pump will solve the vapour things, since it's not connected to the hot engine.

[oil pan 4]

Hows this one?
Kind of cheap with a high lower limit read out.

NavMan Fuel Gauge Model F2100

[TheTestPilot]

The Flow & speed sensor Photos I have posted ,are being used with the mpguino currently,my old zemco was retired when I bought the mpguino .
As for vapour separators ,I used one from a 70's 430 mercury wagon ,it worked ok but the zemco flow sensor could have been though out better ,the optical sensor is just too sensitive .
Later today ,I will post the circuit for the speed /flow sensor here.It's relatively simple so everyone should be able to coble one together.