M20J Rough Engine at Cruise and Engine Failure

[demmert]

This past Sunday I had a short flight planned in my M20J.  My run-up was normal with all gauges indicating normal and no sign of engine roughness.  I took off and climbed to 3500 MSL and leveled off.  During the climb everything indicated normally with no sign of engine roughness and all gauges were within normal tolerances.  When I leveled off at 3500 MSL I pulled the power back to 23" with no sign of roughness.  As soon as I began to pull the prop back the engine got very rough.  I immediately went full forward with the prop and the roughness went away.  I informed the tower I needed to turn back to the airport due to engine roughness.  During the few minutes I had returning to the airport I left the power and prop full forward due to the roughness that occurred.  I came in high incase of an engine failure due to the roughness we encountered.  On short final, I began to pull the power back and lost the engine completely.  I immediately went full forward with the power and the engine started after a few seconds.  I landed and taxied off the runway where I stopped and tried to determine what the problem was.  Once again, I did an extensive run-up and the plane had no indications of roughness and all gauges indicated normally just moments after the engine quit on final.  Two weeks prior to this incedent, I had the plane at the avionics shop getting a new Garmin GTN 650 installed.  During that time I received a S/B from AVStar that the fuel servo that had been rebuilt at the last annual needed to be sent in due to numerous planes with the same servo losing complete power during flight.  The servo was rebuilt and reinstalled before I picked up the plane.  I flew the plane back at 8000 MSL from the avionics shop with no issues.  My mechanic is stumped and has spoke with AVStar and they tell him that if a servo is going to fail it will be a complete failure with no possibility of working after the failure.  Does anyone have any suggestions on where we should start looking for the problem?

[Skywarrior]

Odds are the Fuel Servo is involved in some way. Or maybe fuel pump?

Chuck M.

[LT4BIRD]

Did you use the boost pump on final? If so its most likley not the Engine driven fuel pump.

 I have seen the engine driven pump fail. Check the drain tube on the pump for fuel drainage. If the diaphragm is torn it will pee.

 Most likely not your servo. Check for a stamped "G" on the housing for an AD compliance .

 

The Gaskolator will suck air or get stopped up with contaminates. A bad seal at the fuel strainer will allow air to be sucked in and hence fuel starvation. It also could be clogged. There is an alignment pin on the bowl check the pin.  

Is there any water in the fuel? 

The IO-360 is pretty simple hope and I hope to give you some ideas to look.

[Cruiser]

Glad you and the plane made it safely back on the ground. It sure sounds like a fuel distribution problem and you had work done on the servo. I would be sending it back to AVStar for another look.

How did you manage to land at full power? I would be interested in hearing those details.

[demmert]

Yes, I used the boost pump on final. We will look at everything you have suggested.  Thanks for the thoughts..... 

[danb35]

What did your engine monitor show while the engine was running rough?

[triple8s]

I am by NO means an aircraft expert, however I have been told this from day one as my primary instructor is an IA. " The most dangerous time to fly an aircraft is the first flight after a maintenance activity."

[Piloto]

EMERGENCY AIRWORTHINESS DIRECTIVE

Aircraft Certification Service

Washington, DC

U.S. Department

of Transportation

Federal Aviation

Administration

We post Emergency ADs on the internet at www.faa.gov/aircraft/safety/alerts.

DATE: March 12, 2008

AD #: 2008-06-51

This emergency airworthiness directive (AD) 2008-06-51 is sent to all owners and operators

of Lycoming Engines IO, (L)IO, TIO, (L)TIO, AEIO, AIO, IGO, IVO, and HIO series reciprocating

engines, Teledyne Continental Motors (TCM) TSIO-360-RB reciprocating engines, and Superior Air

Parts, Inc. IO-360 series reciprocating engines with certain Precision Airmotive LLC RSA-5 and

RSA-10 series fuel injection servos.

Background

This emergency AD results from eighteen reports of fuel injection servo plugs, part number

(P/N) 383493, that had loosened or completely backed out of the threaded plug hole on the regulator

cover of the fuel injection servo. These servo plugs were installed with servo plug gasket, P/N

365533, under the plug hex-head. Precision Airmotive LLC investigated and determined that servo

plug gasket, P/N 365533, can shrink from engine heat, causing the plug to lose torque against the

servo regulator cover, allowing the plug to vibrate out. The threads on the plugs were also found

damaged. Servo plug gaskets, P/N 365533, installed on RSA-5 and RSA-10 series fuel injection

servos since August 22, 2006, are made of a different material than the previous gasket part number

used. This condition, if not corrected, could result in a substantial loss of engine power and

subsequent loss of control of the airplane.

[jetdriven]

I would send the fuel servo in.  Also, check the magneto, especially the cam breaker screw and impulse coupler.   This can kill you.   http://mechanicsupport.blogspot.com/2008/08/bendix-d3000-magneto-redundancy.html

[LT4BIRD]

Quote: Piloto

 

EMERGENCY AIRWORTHINESS DIRECTIVE

Aircraft Certification Service

Washington, DC

U.S. Department

of Transportation

Federal Aviation

Administration

We post Emergency ADs on the internet at www.faa.gov/aircraft/safety/alerts.

DATE: March 12, 2008

AD #: 2008-06-51

This emergency airworthiness directive (AD) 2008-06-51 is sent to all owners and operators

of Lycoming Engines IO, (L)IO, TIO, (L)TIO, AEIO, AIO, IGO, IVO, and HIO series reciprocating

engines, Teledyne Continental Motors (TCM) TSIO-360-RB reciprocating engines, and Superior Air

Parts, Inc. IO-360 series reciprocating engines with certain Precision Airmotive LLC RSA-5 and

RSA-10 series fuel injection servos.

Background

This emergency AD results from eighteen reports of fuel injection servo plugs, part number

(P/N) 383493, that had loosened or completely backed out of the threaded plug hole on the regulator

cover of the fuel injection servo. These servo plugs were installed with servo plug gasket, P/N

365533, under the plug hex-head. Precision Airmotive LLC investigated and determined that servo

plug gasket, P/N 365533, can shrink from engine heat, causing the plug to lose torque against the

servo regulator cover, allowing the plug to vibrate out. The threads on the plugs were also found

damaged. Servo plug gaskets, P/N 365533, installed on RSA-5 and RSA-10 series fuel injection

servos since August 22, 2006, are made of a different material than the previous gasket part number

used. This condition, if not corrected, could result in a substantial loss of engine power and

subsequent loss of control of the airplane.