8-17-03
/ 8 hours / 1336 total
Started the engine with new injectors, and didn’t note
any improvement (grumble, grumble).
Here’s the troubleshooting sequence. All testing today was at low power of
3000 rpm and below, and the backup controller never made any
difference.
Original condition:
Normal – rough
(using primaries)
Primary sw off- smooth (using secondaries)
Secondary sw off- rough (using primaries)
Swapped Primary and Secondary wires in the engine
compartment:
Normal-
rough (using secondaries)
Primary sw off- rough (using primaries)
Secondary sw off- smooth (using secondaries)
The above test is of course a contradiction, but I tend
to believe the individual tests, not the one with both switches on.
Rusty, I don't necessarily see a contradiction in the above
condition. In both cases, when the primary injectors are switched OFF
(whether using the Primary Switch (Original Condition) or when using the
Secondary Switch (Swapped Condition)), the engine runs smoothly. I agree that
the second configuration in Normal mode (both switches on), you might expect
the secondaries to run smoothly acting as primaries (since they ran smoothly
as secondaries) - however, that would depend on their flow rate - if the
secondaries are higher flow rate (>460 cc/min), then it might cause the
mixture to be overly rich when acting as primary injectors at lower
rpms.
Replaced Primary injector connectors (pri and sec wires
still reversed):
Things do seem better, but it’s hard to believe,
especially since the original plugs looked so much better than the ones that I
have installed now. Still not
sure this made a difference. The
engine will now run reasonably well with either primary or secondary switch
off, but I noticed that the mixture is way different for each. Maybe this has been part of the
problem all along.
If the primary and secondary injectors are not the same flow rate
then you should expect the mixture condition will be considerably different
for the same mixture and programmed setting. The EC2 is sending the same
pulse width to both sets of injectors. Therefore, if one set has a
higher flow rate than the other, then the actual fuel injected will be higher
for the same pulse width signal.
Put the primary and secondary wiring back to normal,
but left the replacement primary plugs installed:
I
can still make either set of injectors run the engine alone, but turning on
the secondaries, when at 12” MAP makes the mixture go crazy, and I can’t seem
to find a mixture setting that is smooth. I can’t see why turning the secondary
injectors off and on makes any difference at this power setting, since they
aren’t supposed to be on anyway.
Tried manually setting mode 7 at 15” again, and nothing changed (as it
shouldn’t).
You
are right, turning on the secondaries shouldn't have any effect IF the system
has not staged. Unless:
1. There might be a wiring problem OR
2. Your manifold line to the EC2 is not carrying the
appropriate pressure signal. IF it were plugged, leaking or
not attached, then the EC2 could see near WOT pressure signal (29.92"HG) even
at idle rpm and the secondaries WOULD stage (regardless of rpm) and
provide too much fuel at lower rpm.
To
make matter even more confusing, at some point, I noticed that turning off and
on the secondaries at very low power stopped making a difference in the
mixture. This is how you would
expect it to work, but it sure isn’t how it was working a few minutes
earlier!!!
I share your frustration, Rusty. Some of my early injector
problems 'bout drove me crazy - maybe did. In any case, here is my take
on things.
1. First, make certain you know which injectors you have
(flow rate and impedance), otherwise your just guessing at what the problem
is.
.
2. Second, I am fairly certain that Tracy's default MAP is
set for the 460 cc/min stock Mazda Injectors. With these injectors the
idle/low rpm is on the milely rich side, the intermeditate about right, and
the high rpm perhaps a bit lean.
IF you use a 550 cc/m (or higher) in the
primaries then the idle will be considerably too rich, the
intermediate rpm a bit on the rich side and the high rpm probably
close to being on the money. Once the engine is at higher rpm >4500,
the engine will run farily smoothly with a considerable excess of
fuel that would cause rough running at lower rpms.
3. IF I did not know your background, I would
suspect that perhaps you could have a wiring problem in that the
primaries and "cold start" mode might be both on. That would cause way
too much fuel for low rpm, but might run (rough) at high rpm. That might
explain why it would run on secondaries smoothly but not on primaries.
Also, IF the "cold start" mode was on then you would have to turn down the
mixture (Waaayyy down) and program it leaner to get it to run on the
primaries. Turning off the primaries might also turn off the cold start
mode (if in the unlikely case it was miswired). Probably not the case, but might want to check
for certain.
4. Have you put a manifold gauge on the vaccum lines
running from your manifold to your EC2 and confirmed you are getting the
appropriate pressure?
Hope some of this may help
Best Regards
Ed Anderson