For over a year now I have been trying to find a design
for a, for lack of a better term, "FI on dwell time
indicator".

My Civic has 2 injectors, main and aux. So I decided
to use a WWII surplus dual meter that I have had "
forever". I used a 1N4004 and a 5K resistor to isolate
each meter from the ECM/FI. I add a capacitor to integrate
the pulse width and have a "simple" meter that shows me
how long each injector is open. In the 4 FI engines I
would just monitor oninjector because (I think) they
"should" all be pretty much the same.
I had to use a 5uF for the primary and a 20uF for aux.
This morning it was 46F when I left for work and for the
first ~2 minutes the aux was hihger then I had ever seen
it before. The aux is mainly used during acceleration and
starting. I initially used a laptop with a dataq data
logger, but soon found out you can't drive and read a
display!

These values can't be calculated, because it depends on the
meter sensitivity, internal resistance and needle ballistics.
And inches/mm of vacuum doesn't really correlate with injector
on time very much at all. At times you get the best, least,
injector on time with vacuum a lot lower then I would have
thought. I am debating trying to rig a voltage controlled
oscillator with the primary and try to learn to drive with
the lowest tone.

The 10K parallel resitance across the injector will draw a
miniscle additional current. 15V/10K=1.5mA. I used 15v
because it is the highest the eninge should ever see.

Given the constantly climbing cost of fuel, I am after any
sane way to reduce my costs.

Does anyone have a link to one of the hot rodders who might
have mapped out the temp/speed/RPM injector timming?

Terry