I am getting a higher frequency of the hiccups.  Some are pretty violent.  My wife says she can feel the side of the fuselage against her leg when it happens.  I have not had a passenger yet that did not ask “What was that!?”

 

Bill B

 

 

Bill,

 

Last month I flew two three hour flights on back to back days. For the first time I experienced a few hiccup events. I would estimate 3-4 on each day. On the first day my passenger didn’t notice anything but on the return flight he said “what was that!” That event was a little stronger than the others. I considered switching controllers but decided the events were too infrequent for testing. The engine was operating in a colder condition than normal. OAT at altitude was between 17 and 32F. At times the oil and water were in the low 130’s. Need a smaller exit with cowl flaps.

 

 

Bobby

 

 

I went thru and cleaned up all my grounds and it seems to have fixed everything with the exception of the hiccup. 

 

Tracy, have you finished the bench testing on the EC-2 upgrade yet?  I would really like to try and see if that will fix this problem.  My wife really doesn’t like that hiccup!

 

Bill B

 

 

I currently have a separate ground from each of the batteries to a Nuckolls “forest of tabs” ground point.  Everything inside the cockpit grounds here.  Also the fuel pumps and injectors ground here.  The coils ground on the center iron.  There are separate grounds from each battery to the PSRU plate on each side of the starter.  I have considered bringing two separate grounds from the center iron to the batteries just in case there is resistance getting from the center iron to the PSRU plate.

I am also taking all my grounds apart to check for corrosion or anything that seems that it might not be properly bonded.

 

I am doing this for two reasons.  One, I am still getting that occasional “hiccup” that is violent enough to shake the plane when it happens.  It is bad enough that I am concerned that it might be bad for the pin in the PSRU.  I am also wondering if it could be the PSRU that has sheared the pin and is slipping?  Someone on here had that happen and I would really appreciate a description of what that sounded and felt like and also how I could make certain that is not the problem.  No, I don’t want to dismantle the PSRU to check it unless that seems to be the only way to check it.

 

Also, Tracy, how are you progressing on getting the upgrade for the EC-2 that might fix this hiccup if that is what it is?  I think you had it done for the EC-3 and were working on the EC-2 implementation??

 

The second reason for going thru the grounds is that I am having an intermittent problem with my GTX327 transponder, MFD150 moving map, and TruTrak autopilot shutting down.  This seems to happen more often when I key the mike on my GNS430W radio, but keying the mike is not required.  It sometimes happens just out of the blue.  Also most of the time, only the transponder shuts off.  Only sometimes does the moving map and autopilot join in the fun.

 

Everybody tells me that it sounds like a ground issue, hence I am going thru the ground system.

 

I welcome all opinions and input!

 

Bill B

 

 

Tying the engine parts together should not be necessary but you still need a separate ground from battery to airframe ground (if metal) and your avionics ground point.   Also separate feeds from +12 battery to starter/alternator and avionics.  You can Use the starter/alternator feed for coils, injectors & fuel pumps to keep noise down on the avionics bus.

Tracy