Ernest,

The results of your injector tests are really interesting.

Since 400 squirts of 5 ms gave 15 ml and 400 squirts of 20 ms (exactly 4 times as long) gave 60 ml (exactly 4 times as much), the missed flow due to turn on/ off time (m) is zero.  The turn on time and turn off time are both very unlikely to be zero so the implication is that they are equal.  This seems unusual to me as I have not seen this in any injectors I’ve tested.

Again, 400 squirts of 5 ms gave 15 ml but 1600 squirts (exactly 4 times as many) gave 48 and 49 ml (3.2 and 3.3 times as much) where one would have expected 60 ml (exactly 4 times as much).  This also seems unusual since changing the number of squirts should not change the injector characteristics.

Maybe the MS isn’t doing you have told it to do, or there is another parameter that is changing.  One possibility that comes to mind might be the fuel pressure not remaining constant during the test.  Constant fuel pressure might be something worth verifying since if it is not, the fuel pressure regulator, fuel filter, fuel pump, or other component of the fuel system may be at fault.

Steve Boese

RV6A 1986 13B NA RD1A EC2

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The next thing on the agenda was "characterizing" (my term) the injectors.  The Megasquirt has an injector test function.  You tell it how long to fire the injectors, and how many time.  Set it to fire ten times or so for a few milliseconds to verify clickety-click from the injectors, or set up a fixture to capture and measure the sprayed fuel, and you should be able to tell exactly how the injectors are behaving.  I'm not the type to pass up that sort of useless information.

s = milliseconds sprayed
f = nominal flow
m = missed flow due to turn-on/off time
c = cycles sprayed

c(sh-m) =  measured volume

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The raw numbers from the primary injectors  (only one test on the secondaries, and they looked the same).

400 5ms squirts gave 15ml.
400 20ms squirts gave 60ml.
1600 5ms squirts gave 48ml on one injector and 49ml on the other.