Hi David, Yes, if you have fiddled with the MAP table for some time
and still are unable to get a smooth idle, the injector driver change is worth
trying. The large turbo injectors (550 cc) are more sensitive to this
problem so while there is no guarantee that there are no other problems,
there is a higher likelyhood that this could be the answer.
Builders using using the EM2 should send it in as well because the fuel
flow will read too high after the EC2 change if the EM2 is not also
updated.
----- Original Message -----
Sent: Saturday, April 07, 2007 9:08
PM
Subject: [FlyRotary] Re: Renesis full
power fuel burn / EC2 injector driver change
Tracy,
Cool, this is the first I have heard of the injector drive update and I
am hopeful that it might be the key to my idle problems. I have done a
lot of fiddling and still cant beat it. I am particularly interested to
hear what kind of idle issues it fixes, to see if it sounds like mine.
My problem consists of constantly wandering mixture need... (the O2 bar
is constantly wandering full scale without change in throttle, load, or
mixture setting). I have frequent misses, and I have to run my
fuel pressure as low as my regulator can be set (about 32 psi at idle) or
the problem gets worse.
The weirdest thing occurs at shutdown. I shutdown by turning off
the fuel pump. When I do that, the engine runs silky-smoothly for a
second or two before stopping.
That made me concerned there might be some sort of electrical
interference between the fuel pump and the EC2 since they were on the same
buss. I moved the pump to a separate buss, tried a different pump, tried
another buss, and installed a capacitor but none of that seemed to have any
effect.
Do you think it would be worth sending my EC2 in for the new
upgrade?
On 4/6/07, Tracy
Crook <lors01@msn.com> wrote:
EC2 injector drive snubber update.
On the subject of the injector driver snubber change, I had hoped
to make it an easy to do in the field thing but it did not turn out that
way. The physical change is fairly simple (adds a single part to the
board) but the change in injector drive pulse width requirement was so
radical that it is beyond the current range of the injector flow rate
adjustment (Mode 3). This requires an update to the EC2 software
so it has to be done here : (
The same thing applies to the EM2 since it determines the fuel flow by
looking at the injector pulse on time. It could not be
recalibrated to compensate for the change so it's software had to be updated
as well.
OTOH, if you are currently flying the EC2 and/or EM2 and you are happy
with the way it is running, there is no pressing need to change
anything. This is not a safety of flight issue.
This change is only necessary if you are finding it impossible to
get the engine to run smoothly at idle. Note that this is not the only
thing that can cause rough idle so only do this as a last resort to fix idle
problems.
Since I only today got the EM2 software changes installed, I still do
not know if there is any fuel burn improvements as a result of the snubber
change. All EC2s shipped since March 20 have this change incorporated.
Tracy