Electroair failure on runup

RVDan · #1 08-05-2018, 07:05 PM

Just wondering if anyone has experienced the problem that I did today. I was at an airport preparing to return home, and on the runup had a failure of the Electroair system. When selecting the mag off at 1800 RPM, the engine shut off. The EI wasn?t running. I shut down, cycled power and attempted another runup with the same results. I played around a bit and found that I could start the engine on the EI but it would shut down around 300 RPM. It did kick back once and didn?t start on first compression but would start, so there was some level of operation of the system. At any operating RPM running with the mag on, if I shut off the mag the engine stopped

During the prior flight yesterday, everything was normal, 10- 20 RPM drop on the EI and 125-150 RPM on the MAG. No abnormalities were noted during the 40 minute flight.

I tried to do a little troubleshooting without tools and when checking the connector to the EI controller found the controller hot to the touch. Not warm, but hot to the point that holding it was uncomfortable.

I will be talking to EI tomorrow. Anyone have any insights? It is going to be a pain traveling back and forth with tools and parts to troublehoot and get the bird home.

Bill.Peyton · #2 08-05-2018, 07:17 PM

I too have the electro air system. I have 200 hours or so on it at this point. I would be interested to hear what the final analysis shows. Are you using the mag hole pickup or the flywheel timing sensor. It sure sounds like loss of the timing signal.

Where is the computer mounted?

RVDan · #3 08-05-2018, 07:36 PM

Quote:

Originally Posted by Bill.Peyton

I too have the electro air system. I have 200 hours or so on it at this point. I would be interested to hear what the final analysis shows. Are you using the mag hole pickup or the flywheel timing sensor. It sure sounds like loss of the timing signal.

Where is the computer mounted?

MTH that mounts in the mag hole. I was thinking that if it was a loss of timing reference, then the engine would not have started. It is interesting that 300 or so RPM is the transition from the retarded start timing to the run timing. I would think it would need to be a total loss of signal to have the engine simply shut down though.
The controller is mounted in the cockpit on the sub-panel.

BTW I have about 300 hrs on the system. No other problems to date.

Bill.Peyton · #4 08-05-2018, 07:57 PM

I also have the MTH. I assume you have tried reseating the connectors. Also. I recall there is a mod to the mth to modify the washer that holds down The rotating gear assembly. You might look up the SB and check your serial number of the mth to see if it included.

RVDan · #5 08-05-2018, 08:07 PM

Quote:

Originally Posted by Bill.Peyton

I also have the MTH. I assume you have tried reseating the connectors. Also. I recall there is a mod to the mth to modify the washer that holds down The rotating gear assembly. You might look up the SB and check your serial number of the mth to see if it included.

The only SB that I see applies only to the 6 cylinder MTH. Am
I missing something?

Bill.Peyton · #6 08-05-2018, 08:36 PM

Sorry, I have the 6 cylinder version....

RVDan · #7 09-05-2018, 06:55 PM

I thought that I would post and update on the problem and the solution. The airplane was grounded about 150NM from home. I was a in a bit of a hurry to resolve this and retrieve the aircraft as I was headed away for a several weeks on business and didn?t want the airplane sitting on the ramp running up parking fees that long. I retrieved my wiring diagrams, and prepared to go retrieve the aircraft. One trip, bring the airplane home.

In the ancient past, I worked as a mechanic, and the task retrieving helicopters from some remote location tended to be sent my way. Travel out get dropped where the helicopter was and stay until you got it fixed. So, I knew that I needed some spare parts to have on hand. I contact Electroair, and they quickly pulled together some loaners and got them to me before the weekend. Recovery on. Their main pointer was to look at the mag pickup (RPM sensor)

So here is what I found. The main connector is an Ampseal connector. When I removed it from the controller, the wedgelock was unlocked. I examined the connector and found what could have been sockets pushed back. I worked with the connector, plugged it in and the system worked normally. I flew the airplane home and on arrival did a runup and all was good.

I didn?t like the connector condition. On speaking with Tyco, the manufacturer of the connector, the tech support engineer indicated that even though though they say the connector sockets can be removed and reinserted, he didn?t recommend it. The socket retention works great initially, but when removing the sockets it can damage the socket retention fingers. So, I replaced the connector housing, and inspected each pin connection, finding nothing wrong. I carefully assembled the connector, ensuring all sockets were fully engaged.

Plugged in to my original controller and everything ran fine. I had one suspicion and that had to do with the fact that the day I had the problem was very hot and sunny. The airplane sat in the sun with a canopy cover all day. Needless to say the cockpit was hot when I jumped in to go. So the possibility of a heat induced problem existed. I decided to do a heat stress test. I then instrumented the controller with thermocouples and heated with a hair dryer at 125 deg F for 30 minutes. Did a runup and the controller was failed. After cooling down, it then operated again. Just to be sure I changed the mag pickup but that made no difference. So, the problem was a heat induced failure of the controller. I replaced the controller and now up and flying.

Now here is the interesting part. The controller has an LED recessed and not obvious. My controller was behind the instrument and I couldn?t see this LED without a mirror. This status light can tell you good info. On power up, the LED flashes RED briefly then turns green. When you crank the engine it flashes red/green at each ignition cycle. When the engine is running it is green again.

Obviously, the green light lets you know the unit is powered. If you get the red/green flashing during cranking, the RPM sensor (mag pickup) is working. Really helps with the troubleshooting for this kind of problem and it isn?t in the manual.

Electroair indicated that this type of a failure was not typical. It definitely sounds like the mag pickups are the most vulnerable part of the system.

The support from Electroair was great, and there was no charge for the loaners, and they got me a replacement unit quickly.

Bill.Peyton · #8 09-06-2018, 06:09 PM

Dan,
Thanks for posting the feedback.
Bill

FasGlas · #9 09-07-2018, 08:36 AM

ElectroAir has exceptional customer service and very reliable ignitions. I've run ElectroAir going on 20 years, first a single ignition then dual ignition. Not one failure. Mike is always there for questions, ideas and great service. I've installed, tried and dealt with the others.... Not so good.

RVDan · #10 09-06-2019, 03:59 PM

Another update:
During the first hot days in May of 2019, I experienced a repeat failure with identical symptoms as the previous year. I rigged a mirror so that I could see the green led and confirmed the controller shutdown. Ok, now I?m just finding it hard to believe that 2 controllers experienced the same failure, when no one else is reporting this. So I started back to troubleshooting basics, rang out the wiring with pin to pin continuity checks, checked for shorted conductors, all connector pins checked, no problem found. Using a hair dryer, I can duplicate the heat soak failure when installed in the airplane, but not on the bench. I then disconnected all inputs/ outputs in the airplane and couldn?t get the controller to shutdown. Plugged in first the coils, still good, then the RPM sensor, still good, then the MAP sensor, and bingo fails. I decided that the most logical thing that could take down the controller was the 5V excitation somehow getting shorted down. checked the 5V with the sensor unplugged, measured 5 V. plugged the sensor in and it dropped to 3.4V. I checked the MAP sensor on the bench and found it was drawing nearly 60 ma, more than what I would expect. Electroair didn?t know what the MAP sensor power requirement should be, so I returned it and it failed their bench calibration check. A new sensor was sent. New sensor power was measured on the bench at 4.5ma, more like what one would expect. I had concerns that the excessive current being drawn by the failed sensor had damaged the controller?s 5V power supply and was right. When installing the new sensor the 5V sagged well out of tolerance. Exchanged the controller and now everything running fine. Electroair didn?t think it was possible for the MAP sensor to cause the controller to fail, but I proved that wrong. Apparently the 5V supply in the controller is used for other internal voltages, and when it fails, it takes down the controller.

I had to buy the MAP sensor, and the controller was warranty since, It was only 9 months old.

All is good now. Incidentally, I flew without the MAP sensor for about 10 hrs. The low MAP operations were notably better with the MAP advance.