I'm
in a bit of a dilemma and thought I would put this out here for the group to
ponder.
First, this is a p-ported 3-rotor, running RWS EC-2 and psru. I'm
running 460cc Mazda primary injectors and 60lb Deka IV secondary
injectors. Primary injectors share a common fuel rail and are positioned
close to the engine, between throttle plate and rotor face. Secondary
injectors are located ahead of the throttle plates. As this is a p-port
engine, it has three 1-bbl TB's, located very close to the engine. Engine
will idle down to 800 - 900 rpm, but I normally idle it around 1500 - 1600
rpm.
The problem is this, the #1 rotor cuts out at low to mid-range RPM,
evidenced by obvious reduced power, very low EGT's on rotor #1, change in
exhaust tone, a dark residue in the #1 exhaust port and dark spark plugs on
#1. Just today I was able to get it to run normally with balanced EGT's by
adjusting Mode 4, but I had to go full CCW with the program knob to
achieve this. (Mode 4 & 5 adjust similar to Mode 1) Now it runs
well mid-range and the dropped #1 rotor is happily firing away. I still
have some tuning to do, but after adjusting Mode 4, I can now move forward with
that.
To date I have tried the following:
1. Performed a compression check - OK
2. Swapped primary injector with #3 - no change
3. Swapped coils with #3 - no change
4. Replaced spark plugs - no change, except initially it ran
better until the plug fouled
5. Checked plug wires with ohm meter - checked good
6. Sent EC-2 to Tracy for latest s/w and checkout - no
abnormalities found, latest s/w installed
7. Checked secondary injectors for leakage - none seen
Can anyone suggest a reason why the #1 primary injector runs extremely rich
when set to the factory default setting? Is this something to be concerned
with?
Thanks,
Mark