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On Mon, 6 Jul 2009 16:04:37 -0400
"Ed Anderson" <eanderson@carolina.rr.com> wrote:
<snip>
Any time the EC2 is not grounding its' side of the injector (causing it
to inject) there is 12+ Volts at the EC2 injector pin on the EC2 box -
Unless you have turned the disable switch for that pair of injectors
off (no voltage to injectors). Until the EC2 grounding pulse there is
no current flow and therefore no voltage drop across the injector. So
if there is 12+ volts on one side then there is 12+ volts on both sides
including at the EC2 injector pin. Once the ground pulse is sent then
the voltage is dropped across the injectors and there is indeed near
zero volts on the EC2 pin. So I would think it would be easy for the EC2 to sense whether there is
12 volts on that pin between injector pulses and if there is 12+ volts,
then the EC2 would know it is powered up.
Yes, that would work, so it's quite possible that the EC2 is keeping
track of which injectors have power. I take back the blanket statement
that it isn't happening. Sorry Steve.
<snip>
Ok, we are now below staging point cooking along on two primary injectors (I
know you disagree with this point, Bob, but bear with me) When you drop
below that staging point the EC2 automatically doubles the nominal pulse
duration because you have stopped using the 2 secondary injectors.
Normally you are using the two primary injectors below staging. So we still
have the same fuel flow below with 2 injectors that we had above staging
point with 4 injectors – so fuel flow both sides of the staging point is the
same (ideally). Engine runs fine.
Now, while below staging, you manually turn off the primary injectors by
turning off their disable switch. This removes power from the primary
injectors and grounds the cold start circuit. But - wait, I postulate that
below staging the cold start circuit is already in effect (doubling the
pulse duration). So there is no further doubling and the EC2 senses power
removed from the primary injectors, senses power is still there on the
secondary injectors and immediately starts firing the secondary injectors.
Engine Runs Fine.
NOW IF this theory is correct then turning on the cold start switch on the
PCM panel with only one pair of injectors operating below staging - should
do nothing regarding the pulse duration as its already double that that
nominally required for 4 injectors. Engine Runs Fine.
<snip>
OK, but Steve has already reported that if he turns on the cold start
switch while at idle, the engine will run rich and die. I'm pretty
sure I've done the same thing. If one set of injectors is turned
off, then the engine will run fine. I think the cold start doubling
and the staging pulse modification (halving on the way up and doubling
on the way down) are independent from each other. At least I think I
understand our differences and thats some progress. :) I've always
assumed that the cold start switch on the PCM would always double fuel
flow and setting cold start when disabling a bank of injectors would
always keep fuel flow the same (within limits).
Bob W.
--
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
3.8 Hours Total Time and holding
Cables for your rotary installation - http://roblinstores.com/
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