gaui supplied cdi unit

[thebirdman]

Anyone having issues with this Unit?
Have been fighting a stalling problem since break-in, kept thinking it was a fuel issue.
Happens 2 - 2 1/2 minutes running high rpm, will sit and idle now all day long.
Maddened last week-end, 2 minutes in engine started sputtering and quit, I know I need to practice my auto's, but on my terms please lol

Will not restart, wait 10 minutes and it will light right up.
engine temp when it quits is 120-130 Celsius.

Have tried separate battery packs today, no change..
Another issue I'm seeing is it will not always initialize correctly, get servo flutter...that is why the separate pack trial...
Using a Silverline and VBC

Any thoughts?
tyia
thebirdman

[kane601]

My CDI did the same thing. It would idle great but once I got to half throttle it would shut off. I moved the sats and the problem was still there. I ended up replacing it with the evolution CDI. That problem was gone until that CDI failed, I replaced it and is was working good the last time I fired it up. I'm sure it's good still I just switched to the os 55.


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[thebirdman]

Hi all, well several months have passed, thought I'd finally found the issue last time as the rpm sensor failed, replaced yesterday and again today 2 minutes in poof goes the T10, instant shut down? If I had no patience I'd put the nitro in it lol...
3 different cdi units.. stock rci unit, os unit, chi unit...
Have isolated the fuel system to running just off the header tank
Have ran separate batt packs for Ignition and FBL
Have replaced throttle servo
Have bypassed optikill switch
2 different rpm sensors
2 different bec's
several different plugs
????????????????
@ a loss? This thing will idle for 4+ hours and no hiccup's?
There is no rpm change before it happens...like a lean condition
Still have full throttle control when it dies, FBL unit still functioning, RPM still there on the vcontrol.
It's like the pissed off heli god just turned of the key )
I've tried looking for spark at the plug before and after and too hard to detect, the plug is so small, almost impossible to see ...
Have started it "so know spark is there" removed plug and spun over...you just cant see it?
Installed plug and it will start right up...
What's driving me nutz is if you let it sit for 5-10 minutes, it will fire right back up....
I don't think I did anything to piss off the heli-god's? but who knows?

I'm going to pull the engine back out....has to be a problem with it some where? although it sound's like an electrical issue, I've covered all area's several times?

Have 3 options left,
-Did receive my rotorstar motor that I was going to use as the ginnie pig for the evolution rod upgrade, no rod has not arrived yet?, that means another long breakin for the engine.
-Loose the vbar FBL unit and replace with another FBL unit?
-Bench mount the motor with manual throttle control, ignition, and a nice big prop lol

And why did I go gas??? thought 30 minute flight times would be cheap and cool.... so far getting 2 minutes lol

Oh and a forth option...package up and send down to gas powered thought's in the fall and give them the winter to work it out

[HelisRock]

Sorry to hear you're pulling your hair out. I had problems with excessive emissions that took numerous tries to get rid of, so I feel your pain.

Could be fuel, air or spark.

You had a problem with the rpm sensor? I assume that's for the gov? Try the minimum - RX, throttle servo, CDI. No FBL, No Gov, No nothing. Run it up without blades.

You might get the RCEXL test equipment to check everything out. Hall sensor test kit, ignition box test, mini tach.

If you pull the spark plug, you should be able to hear the spark, but the plug needs to be grounded to the engine. Try it at night, both in and out of the engine. With the plug in, you might see sparks if the plug cap/boot isn't seated well or is compromised.

I'm running one Life batt that powers RX, Servos, CDI, everything. No problem.

Running for 2 minutes suggests it could be excessive heat or vibration. Where and how is the CDI mounted? Use one of your spares, don't mount it on the heli, sit it on foam next to the heli and run it up without blades. Also could suggest fuel, maybe the vent? You tried running just off the header tank, was it vented properly? Grab a tank/plumbing you trust, sit it next to the heli and run it up without blades.

Since it's been up and running, you're sure it's not needles/tuning, so no need to look there?

No end to things to try!

[thebirdman]

Hi helisrock,
auto tech for 30 years the cdi unit's are self contained, ground is ran back through the outer sleeve. If it didn't you would have efi interference everywhere, specially with carbon frames.
Using vcontrol so bank 1 is set too linear control for startup, no gov
Running up for a couple sec's no blades, you'd get away with, 2300 rpm 2 minutes=new engine
I'm really pointing this to an issue with an air leak probably at the carb gasket and temp, although I don't see/hear any change in rpm or smoke....but if a vacuum leak forms and engine is deprived of fuel, the issue could happen that quick?
I've covered the electrical in every direction, have to start looking at simple things lol