Steve
I would limit running the engine to a minimum at or above the problem rpm point. I don't think it's good for the gearbox and may create torque reversals.
The CAS voltage clamp is installed outside the EC2. Tracy may have added the final 1K fix internal at some point during upgrades. It's an easy test if the CAS wiring has slack and in accessible location. Cut the 2 wires for the CAS and twist in a 1K per Tracy or test the zener circuit. If it corrects the problem clean up the wiring. My circuit was installed about 8" from the EC2 connector. Mark Steitle adapted a renesis CAS to his 20B and experienced the same symptoms that started in the low 5k rpm range. During testing we spliced in a long section of CAS wire through a breakout block. The breakout block allowed us to monitor peak to peak voltage that increases with rpm and easily jumper in and test higher resistor values. The long wire allowed us to run the engine outside the hanger and not disturb the test bench setup and o-scope. As we increased the resister value it would push the problem area to a higher rpm point. Please note that this was done before Tracy identified and recommend the 1k fix.
Does the rpm display problem and engine stumble happen at or near the same rpm point? I'm not sure how the injector signal would look when fully saturated. Temporally crank up the fuel pressure and see if the problem point moves to a higher rpm. Temporally lower the staging point. Use mixture knob to control with no tuning changes.
Are the injector and coil trigger wires ran separately from their power sources?
Back to the coffee pot. Bobby
Hi Dennis
Yes the EC2 is programmed for chev dwell.
I thought the mod to the EC2 was just that, perhaps Tracy might remember from the photo.
If Tracy cant remember I’ll have to trip the heat think off which I’d prefer not to do.
It would be easy on the bench but harder in the aeroplane to put a cro on the CAS inputs.
Thanks Dennis
Steve
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Steve
Your problems sound similar to what I experienced when I first started my 4 port Renesis about 8 years ago - I was the first person to use the Renesis ignition coils with the EC-2. Tracy modified my EC-2 to work with the Renesis coils. I see you have the D585's. Did you have Tracy specifically build your EC-2 up to work with these coils?
Also - the crank angle sensor on the Renesis required a Zenor diode and resistor in the circuit to clamp the output to the EC-2 to around 5 volts. Do you have this modification between the CAS and the EC-2?
Dennis H.
----- Original Message -----
Sent: Friday, August 05, 2016 6:31 PM
Subject: [FlyRotary] Finding the gremlin
Hi Guys
We got some further fault finding done today towards isolating the cause of the massive missing problem with our Renesis 4 port.
The troubling symptom / major problem is as we approach 23-24” MAP at various prop pitch and rpm’s (both A and B computers),
with very little warning begins to miss and then pretty much go immediately into massive missing and popping in the exhaust.
Just before the bad stuff begins the EGT’s read 1540 and 1440.
I have only done mode #3 programming and adjust the mixture with the manual mixture control while watching the narrowband. The mixture tables were reset.
It stages at 19”Hg as per Tracy’s recommendation for Red and Blue Injectors.
Also the Skyview and EM3 stops displaying RPM at around 6000 rpm. The EM3 reads NOP instead.
So order of events today:
I wondered previously what the seals where like so having received a new $22 pressure transducer I took out trailing plugs and
grabbed some pressure data while cranking.
See plots in WORD file attached - (File to big, I’ll have to reduce before posting)
All faces around 80psi when cold. Rotor #2 has one pulse down by max of 6 psi compared to the highest pulse. Does this mean that side seal is leaking?
We then went after 3 key possible problems:
1st being Engine monitors holding Injector #1 open so:-
A. Disconnected Dynon engine monitor to isolate it as a cause of disturbing Injector #1. No change.
B. Disconnected EM3 to isolate the same as above. No Change.
2nd being Pulses in the intake manifold messing with EC2 fueling.
We inserted a 0.6mm restriction in MAP sense line. (This line then ’t’s’ of too A and B Computer MAP’s. No Change.
3rd Renesis CAS generating higher input voltage. Tracy recommends 1K across CAS’s.
I think this mod may have been done. See photo of EC2 PCB below pin 4 & 23 both tied back to pin 22 via something inside the heat shrink.
Note to Tracy. - Did you incorporate in your code any way of knowing if the EC2 entered a watchdog routine?
So I’m stumped for the moment.
At least we know more of what the problem isn’t, Which is helpful.
Appreciated any input.
Cheers
Steve Izett
<EC2PCB.jpg>
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