Engine problems

[docron.ski]

I purchased my CC last March while it was being repaired and anualled at CubCrafters. I hired a ferry pilot to bring it back to OH and on the way, she had partial power loss and and had to stop for repairs. The ignition coils and plugs were replaced and she completed the trip uneventfully. I noticed that on rare occasions, the engine seemed to loose power for about a second, just enough to get your attention, then perform normally for the rest of the flight. Nothing was found on this years annual 5 flight hrs ago. Yesterday, I lost partial power that continued for the 15 minutes that it took to get back to my field. Cylinder head temps on #3,#4 and EGT on #3#4 went high and I had to reduce throttle to about 1700 rpm to keep cylinder head temps below 400F. I suspect ignition problems again. I downloaded trouble shooting guides from CubCrafters and Light Speed and will begin to investigate tomorrow. I suspect that the ignition coils are not the primary problem and that something is causing the coils to fail. Has anyone had problems with the electronic ignition? Any ideas?

[Pete D]

Has there been any metal in the oil?

I have seen one engine built several years ago that had a couple of cam followers that were not hardened right. (FAA-PMA'd parts) They gradually wore the cam lobes down until occasionally you would get short periods of odd running, usually on climb out. I think the valves were floating or something. Never really saw a large amount of metal in the oil but it consistently had a small amount.

How old is your CC?

[docron.ski]

Has there been any metal in the oil?

I have seen one engine built several years ago that had a couple of cam followers that were not hardened right. (FAA-PMA'd parts) They gradually wore the cam lobes down until occasionally you would get short periods of odd running, usually on climb out. I think the valves were floating or something. Never really saw a large amount of metal in the oil but it consistently had a small amount.

How old is your CC?

Cub is 2011, Serial # C11-00170. It was annualled at CubCrafters in Aprilaa 2013 as part of the pre buy inspection and May 2014 at Execytive Air in Musgegon,MI. No mention of metal in the screen. I just had a filter installed this last annual.
Would a cam problem cause the cylinder head/EGT temps to go high? I just pulled the plugs and they are quite sooty in cylinders 3/4, less so in 1/2.

[turbopilot]

Since you're looking at EGT and CHT information you may have the Dynon Executive panel. If so, you should download your engine data during the loss of power event and post it here. Would be easier to help diagnose the problem with a full data set of engine parameters.

[Dan L]

I noticed that on rare occasions, the engine seemed to loose power for about a second, just enough to get your attention, then perform normally for the rest of the flight. Nothing was found on this years annual 5 flight hrs. Any ideas?

This describes a problem I had a couple of months ago almost exactly as I experienced it. I had just installed the new intake sump kit and flew it for a few trouble-free hours. But then I had these short power losses, dropping a few hundred rpm's for a second or two and then normal performance. Of course I figured it had something to do with the kit. I decided to take a look and see if there was anything obvious before removing the kit. There was something obvious. A frayed end on the scat. I replaced it and no more trouble.

[docron.ski]

Since you're looking at EGT and CHT information you may have the Dynon Executive panel. If so, you should download your engine data during the loss of power event and post it here. Would be easier to help diagnose the problem with a full data set of engine parameters.

Good idea, I'll try to down load the data tomorrow. This is not the first time the engine had this problem. At Tach 172.5, on the ferry flight from Yakima to OH, the ferry pilot had the identical problem.

"Thanks for the thoughts on the engine problem, I can see that you've been dwelling on the problem also. We also thought of the intake leak which was the first thing we checked, but all checked out OK. With the electronic ignition, the "mag" check has no drop,it only checks that each ignition is working. With 459W, at cruise, over Iowa, the engine would run rough for a moment, then fine, then rough again, like at night when you imagine things but aren't sure. Leaning, enriching, or carb heat had no affect. The roughness increased in frequency and lasted longer until it mostly ran rough and RPM dropped 200-300. Both the #3 and #4 CHT went to about 450. I decreased power(RPM) and it would run fine under 2000RPM and landed.

The "experts" were a bit baffled by the high temp in 2 cylinders instead of just one. This seemed to rule out fuel contamination, single ignition failure, spark plugs, vacuum or anything that affects one cylinder or all cylinders. They did a good job of finding out what the back 2 cylinders have in common. They share a cam lobe but compression was good and the valves were operating normal, thank god ($$$). The other thing they share is an ignition coil. The roughness happened 2 times, the first time it cleared up. Both were after the engine had been running for at least an hour so heat could affect the coil causing the high CHT. I'm not sure how that part works but that's why we have the experts. So, all are confident that the new coil will correct the problem. Stan Franz, CubCrafters, is sending coils, plugs and carburetor overnight. The unneeded parts will be returned.
This is kind of the long version of the 459W story, but things here in Iowa are pretty slow so I have time to write. Weather is good, autopilot works well, plane flys well and starts right up. It's a joy to fly.
Keep those ideas coming. We'll get the problem solved."

I think it is the coil again at tach 2005.5 The question is why? There must be a primary problem that is causing the coil to fail.
Anyone else have problems with the electronic ignition?

[Thomas]

Dan,
I had a similar experience a few years ago in a Pazmany PL2, took off and then couldnt pull more than 1800 rpm.
Slowly made it back to the airfield and found the scat tube had collapsed and was blocking the intake. I changed it to SCEET
tube which is stronger (two ply's) perhaps we should look at this as the length of the intake SCAT is about 10" long and must be continually flexing.
Bruce

[glickle]

One other thought. Since its a 2011 model it may or may not (check with CC) have the rerouted electronic ignition/ wires. If not I had intermittent problems that sound somewhat similar in that the engine would run seriously rough and lack of power but I could still fly and usually returned to the airport to find on start up again it ran fine. Totally baffling and also on ocassion due to the weak starter/battery conbo the engine would backfire on start up. These two issues were resolved when Randy suggested taking a look at how close any of the Lightspeed ignition wires were to any plug wire as the charge could cause an early firing on the ignition. I zip tied away a few that were definaltey closer than 1 inch to each other and problem went away. So Might want to take a look and if so thats an easy fix. This routing I notice has been changed on the newer models and my new plane 2013 does not have any of these issues. best Gary

[docron.ski]

Here is the data from the Dynon 180 FlightDeck showing the last take off from a neighboring field. I have not been able to figure out anything that would help explain the cylinder head temp going high and power loss.

[DRL]

Here is the data from the Dynon 180 FlightDeck showing the last take off from a neighboring field. I have not been able to figure out anything that would help explain the cylinder head temp going high and power loss.

Just an idea, but it would be worthwhile to check or change the RG400 wire to the ignition coil connectors. These are flag terminals that require a unique crimp die to make a good connection, they are not designed for RG400. If they become intermittently loose, it will damage the coil. Another thing to check is that the spark plugs are firmly connected to their leads. They can look ok, but not be firmly attached. Separating the various ignition related wires is important, but with that much time on the airplane it doesn’t seem that would be the problem.

Your engine data looks similar to ours. We use Savvy’s website to get a graphical look, which helps to quickly compare how RPM and Fuel Flow relates to the EGT, CHT. In our case, during the break-in, we had a few misses at high power until we started leaning early and aggressively.

Fuel and Ignition are the usual culprits, not likely a cam or stuck valve, but those are possibilities. Let us know how this turns out.

Dave