Here is a low cost fuel flow meter from Tracy Crook that should work
with just about any engine using four electronic injectors.
With minor modifications it can be used with any number of injectors.
I redid (cosmetically) Tracy's original schematic somewhat.
With his permission I will post it on the ACRE NL web site.

Paul Lamar

Will this work with subtracting the fuel in the return line?

AI Nut

Yes it will as all it does is measure the fuel coming out of the
injectors. Many car computers use this info to calculate the instant
and average MPG and display it on the instrument panel. My 1992 Dodge
Caravan has such a display.

Paul Lamar

Paul,
What would be required to use this on a 20B??
Don

I suspect minor changes in some of the resistors. Perhaps a 50% decrease in the
value of R4. Perhaps Tracy knows exactly. The principle I think is it is only 
looking at one injector pulse and the circuit assumes there are four pulses.
Is this correct Tracy or is your computer computing the combined data
and putting out one pulse trains with period and width adjusted accordingly? 

Of course the max reading in a 3 1/2 digit 0.2 volt voltmeter would be 1999 
or 19.99 gallons per hour. Some other voltmeter module probably should be used 
because at full power full rich 20B will probably suck down more than 19.99 
gallons per hour. One could of course move the decimal point but the DC input
voltage to the voltmeter would be further down in the noise level at low
fuel flow rates. Long story and it would take several paragraphs to explain
this better. Better to change the voltmeter IMHO to something else like a
full four digits. I'll be interested in what Tracy has to say about this.

Paul Lamar
 
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