Sounds like a possible wiring cross up
John. YES, the ground wires going to the injectors from the EC-2 do control
the on/off of the injectors. The injectors has 12 Volts applied to one of its
two pins, the other pin runs to a injector grounding pin on the EC2 (don’t
have my diagram right handy). When the EC2 is not running but there is power
to the injectors there will be 12 volts on both sides of the injector. This is
because in order for the EC2 to open the injectors it has to complete the circuit
to ground. When the EC2 does ground its end of the injectors lead, then
current flows through the injector, yanking it open and fuel flows. So if
there is for some reason power to the injectors and for ANY reason one of the
injector wires is unintentionally grounded that injector will lock full open
and if pumps are running will quickly flood your engine. The EC2 does not have
to be running for this to happen if your wiring has a short to ground on one
(or more) of the wires running from the injectors to the EC2.
So check it out. It sounds like when you
put the fuse in then you are providing the power to the injectors which appear
to have their EC2 side continuously grounded (at least one of them). The EC2
when operating will periodically ground the injectors to open them – but,
will not ground them when turned off (or rather SHOULD NOT). So check with a
volt ohm meter between each of your injector leads going to the EC2 (I presume
there are 4). Put one lead of the ohm meter on each of the injectors wires
going to the EC2 and the other lead to a known electrical ground with the ohm
meter scale (if its not automatic) set say on 100 Ohms or thereabouts. , I am
not certain what the ohm reading should be – but it should not be very
low. if its reading less than 50 ohms there is probably something shorted, if
the reading is near 1 ohm then its almost certain you have a short to ground..
In other words if you have anything indicating that an injector lead to the
EC2 is grounded then that is the problem.
Ed
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of John
Sent: Wednesday, May 19, 2010 9:59
PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] fuel
injection
Ed, I ran the engine again after supper tonight until it was
warmed up, with the normal procedures, shut it down and let it sit for 15
minutes with master off. Turned on the fuel pump, removed the fuse going
to the primary and secondary switches and left the switches in the off position
and started the engine, which started immediately. If I put the fuse in
for the fuel injection, the wire that Bob White said was the fuel injection,
the engine loads up with fuel. I'll do some checking tomorrow. Does
the ground wires going to the injectors from the EC-2 control the
injectors. JohnD