flyrotary@lancaironline.net Mailing List Archive

I am currently at a loss as to what a “VR sensor” would be??

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Ernest Christley
Sent: Wednesday, January 09, 2013 9:38 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Aeroquip hose changed to hiccup

A problem that mimics a poorly wired VR sensor, but

-only happens occasionally,

-with various levels of "response"

-and is getting worse.

Bill, if you haven't done so already, I would suggest changing the wiring to the VR sensor completely. It sounds to me like a textbook example of the worst sort of electronic malfunction you can have…an intermittent open. You'll never find it under normal test conditions, and it will manifest at the most inopportune times. The only way to completely rule it out as a failure scenario is to completely replace the circuit path.

On Jan 8, 2013, at 11:42 PM, Bill Bradburry wrote:

No, I have the 2.85 gearbox. I have the MT electric prop, so I fly WOT and use the prop to govern the engine speed.

I have changed the plugs with no effect. The mixture is fine when this is happening. Fuel pressure also. I had an incident once on take off like you describe where the plane was backfiring like crazy just after I lifted off. I had the mixture too rich. I dialed it back and everything smoothed out. This is different. It doesn’t really backfire. It is a thump and it jerks the engine and plane. You can hear and feel it. It seems to be a single thump and it has varying degrees of violence. Some are just a little miss and some are so bad it shakes everything. These are less frequent, but they are bad enough that I don’t think they are good for the PSRU, prop, or engine mount.

That is why I have been bugging Tracy about the change for the EC-2. I have my fingers crossed that this will fix it. :>)

Bill B