Cut out at idle

[Brian Stuart]

I have a 2005 Ovation GX2 with 900 hours.  I have had trouble with the engine shutting down after landing after a 1 hour flight or longer.  Just quits and has done it during the landing roll and whilst taxiing. It only happens when the engine is fully hot and never when cold when it idles perfectly. It can be restarted with a hot start procedure but am worried that it may shut down at low power settings on final and then having a glider to get me over the fence. I believe that there is a very sensitive idle fuel pressure adjustment??  Unfortunately my G1000 is 1st generation and does not allow data logging.  It would be so much easier if it did. Can anyone help or has encountered this problem?

Any help would be greatly appreciated.

Brian Stuart (Australia)

 

 

[Guest]

2 hours ago, Brian Stuart said:

I have a 2005 Ovation GX2 with 900 hours.  I have had trouble with the engine shutting down after landing after a 1 hour flight or longer.  Just quits and has done it during the landing roll and whilst taxiing. It only happens when the engine is fully hot and never when cold when it idles perfectly. It can be restarted with a hot start procedure but am worried that it may shut down at low power settings on final and then having a glider to get me over the fence. I believe that there is a very sensitive idle fuel pressure adjustment??  Unfortunately my G1000 is 1st generation and does not allow data logging.  It would be so much easier if it did. Can anyone help or has encountered this problem?

Any help would be greatly appreciated.

Brian Stuart (Australia)

 

 

I would have the engine fuel system checked and adjusted per Continental SID97-3G.

Clarence

[carusoam]

Adding to the experience collection...

I had the engine die while taxiing after landing. About last June, in NJ...

Found it odd, but restart was immediate.  I was uncomfortably in the middle of an active taxi-way...

Taxied and parked in the wrong place with a full shut-down... restarted again (with advice from Brian / @orionflt from KUKT, again no problem...)

Taxied and parked on the grass at a NJMP fly.... 

All that detail, just to say... It is comforting to fly with other MSers around....

 

electronic ignition is going to be soooo cool when it is more developed...

Hope that single point of experience is helpful...

Throttle full out, mixture and prop full in.... weather was warm...

Best regards,

-a-

[gsxrpilot]

My 252 suffers from this malady as well. I've been told it's common to my TSIO360. I've never had it quit in the air, but it often quits while slowing on the runway or on the taxiway. A quick shot of prime or throttle will usually keep it running. I wonder if the windmilling prop is what keeps it from happening in the air?

[kortopates]

1 hour ago, gsxrpilot said:

My 252 suffers from this malady as well. I've been told it's common to my TSIO360. I've never had it quit in the air, but it often quits while slowing on the runway or on the taxiway. A quick shot of prime or throttle will usually keep it running. I wonder if the windmilling prop is what keeps it from happening in the air?

As @Clarence said above for the OP,  this is a clear sign that the idle adjustments are off - but once anything is changed you have to go through both idle and max power according to TCM specs now published in M-0. But one or a combination of the 3 idle settings are off: idle mixture, idle rpm or unmetered fuel pressure. Idle mixture is very common and one you can check on your own. After running full rich at 1000 rpm bring it back to min idle rpm around 700, then slowly lean mixture till it dies. You should see a RPM rise of 20-50 rpm before it does - any more its overly rich, any less its overly lean.

[ArtVandelay]

The last thing I do during runup is to pull throttle to idle...if you do this does it cut out, or is it only after flight.

 

[gsxrpilot]

50 minutes ago, teejayevans said:

The last thing I do during runup is to pull throttle to idle...if you do this does it cut out, or is it only after flight.

 

Only after flying. It never cuts out pulling the throttle all the way back after the runup.

[Guest]

Hot after a run up is different than hot after flight.  Something in the fuel system is calling for attention.

Clarence

[orionflt]

hey Brian,

I want to pay for me to come to Australia I would be happy to take a look at it  .

But seriously as doc said get your fuel system checked out, continental fuel systems have a bunch of moving parts and they all have to be adjusted just right or you will have issues. couple things to note is your FF/fuel pressure during takeoff and whether your on the rich or lean side when you shut down (assuming you can keep the engine running with the throttle pulled all the way back). also check what RPM the engine is idling at and what the fuel pressure is when the throttle is pulled all the way back.

note your FF/pressure on both the initial takeoff and subsequent takeoffs to see if it changes, and the low RPM and rich/lean check should be done after the flight. 

Brian

[DonMuncy]

3 hours ago, gsxrpilot said:

My 252 suffers from this malady as well. I've been told it's common to my TSIO360. I've never had it quit in the air, but it often quits while slowing on the runway or on the taxiway. A quick shot of prime or throttle will usually keep it running. I wonder if the windmilling prop is what keeps it from happening in the air?

On the Continental engine, this is the typical problem when the idle mixture is too lean. Check and see how much of a rise in RPM you have at idle cut-off. If it doesn't rise 50 to 100 RPM before shutting down, it is too lean. Have your A&P or hangar elf adjust the idle mixture until the correct rise occurs. 

[cbarry]

This issue makes me wonder if there’s  a lag in the altitude compensating fuel pump’s metering process when returning to lower altitudes while at lower power settings resulting in too lean of mixture?

[Robert C.]

Hi Brian,

i went through the same problem with my 2006 O3. My engine regularly quit on the runway or right after turning off. Generally in the summer but not exclusively. A big tip-off to my A&P was that I couldn’t get my engine (when hot) to idle below 920 rpm.

Clarence - M20Doc - is (as usual) correct. Get the fuel flow at idle adjusted and you should be good. 

Robert

[jlunseth]

23 hours ago, DonMuncy said:

On the Continental engine, this is the typical problem when the idle mixture is too lean. Check and see how much of a rise in RPM you have at idle cut-off. If it doesn't rise 50 to 100 RPM before shutting down, it is too lean. Have your A&P or hangar elf adjust the idle mixture until the correct rise occurs. 

Or too rich. That can happen also.

This happens, or almost happens, in my aircraft because I typically land with the mixture very lean.  If I do not do that the engine burbles during final because it is running too rich.  The engine runs fine very lean in the air, but on landing and rollout the engine is no longer getting help from the prop.  I always push the mixture in once I have touched down, except when I forget, and when on those very rare occasions I forget, the cure is to push the mixture in quickly and touch the famous top corner of the high boost with the switch cover in place. That gives the engine an immediate fuel boost and so long as the prop is turning the engine will keep going.  You may need to hold the button down until the mechanical pump is pushing fuel again.

I think there are two reasons for this.  One is that there are two mixture settings, the full power and cruise setting, and an idle setting.  When the full power mixture gets moved up, the idle mixture needs to be checked again.  I always have to get on virtually any mechanic to get sufficient fuel flow for full power ops, invariably they set it a little low.  And when I do readjust the full power flow, invariably the idle mixture is off again.  They always need to check the idle mixture.

My engine does not like to idle at 900 anyway.  Among other things, the alternator output drops too low and the "Low Voltage" alerts all start flashing.  I normally keep it above at least 1000 rpms.

Our OP is an Ovation driver it looks like, so these comments are not directly applicable, but I will bet that is what is happening.  The idle mixture setting is either too rich or too lean, either one will kill the engine.  

Edited August 22, 2018 by jlunseth

[StevenL757]

22 hours ago, kortopates said:

As @Clarence said above for the OP,  this is a clear sign that the idle adjustments are off - but once anything is changed you have to go through both idle and max power according to TCM specs now published in M-0. But one or a combination of the 3 idle settings are off: idle mixture, idle rpm or unmetered fuel pressure. Idle mixture is very common and one you can check on your own. After running full rich at 1000 rpm bring it back to min idle rpm around 700, then slowly lean mixture till it dies. You should see a RPM rise of 20-50 rpm before it does - any more its overly rich, any less its overly lean.

Agree with both.

This is something we check every annual and adjust as needed.  To the OP - add this to your mechanic's annual "to-do" list if not already.  Personally, my IA and I go fly before we dive into anything else related to the annual, and we check it before takeoff and again after landing to identify any anomaly.

Steve

[kortopates]

21 hours ago, cbarry said:

This issue makes me wonder if there’s  a lag in the altitude compensating fuel pump’s metering process when returning to lower altitudes while at lower power settings resulting in too lean of mixture?

None of the factory Mooney's have a altitude compensating fuel pump. Even though many of the  IO-550 variants do have this feature, such the later Bonanza A36, the -G model used by Mooney does not. Its too bad because its a nice feature to have since it simplifies mixture management once set due to altitude changes like descents. So because the Mooney lacks it, we do need to enrich on descents from the increase in MAP or pulling MAP back. (Turbo fuel pumps use the same baro chamber but its referenced to upper deck pressure and not ambient pressure).

Edited August 22, 2018 by kortopates

[Brian Stuart]

Many thanks to all for your replies.  It appears that the problem lies in the 3 idle adjustments.  I have had the fuel system reset to TCM 97-3G and it was no better.  At idle it stalled immediately upon leaning which to me showed it as too lean at idle.  My LAME (AP?) then richened up the idle to show a 50 RPM rise on idle leaning.  I then flew for 1.5 hours and upon landing the engine failed to response to small power increases.  I kept introducing power until FF and then it lagged for 1-2 seconds before responding.  I then returned home and landed and it did the same thing.  No response to small (vernier) power increases and only responding to FF which resulted in 2 landings in 1.  This has rendered the aircraft unserviceable and I am getting frustrated.  My AP is not keen on doing anything outside 97-3G but I still have the same problem so there has to be some contributing factor/s.  I will take your replies back to my AP and see how he responds to the above information.  Any help is greatly appreciated.

Thanks Brian.  

[Guest]

3 hours ago, Brian Stuart said:

Many thanks to all for your replies.  It appears that the problem lies in the 3 idle adjustments.  I have had the fuel system reset to TCM 97-3G and it was no better.  At idle it stalled immediately upon leaning which to me showed it as too lean at idle.  My LAME (AP?) then richened up the idle to show a 50 RPM rise on idle leaning.  I then flew for 1.5 hours and upon landing the engine failed to response to small power increases.  I kept introducing power until FF and then it lagged for 1-2 seconds before responding.  I then returned home and landed and it did the same thing.  No response to small (vernier) power increases and only responding to FF which resulted in 2 landings in 1.  This has rendered the aircraft unserviceable and I am getting frustrated.  My AP is not keen on doing anything outside 97-3G but I still have the same problem so there has to be some contributing factor/s.  I will take your replies back to my AP and see how he responds to the above information.  Any help is greatly appreciated.

Thanks Brian.  

More info from the M20R manual and S/I M20-107 

https://cdn2.hubspot.net/hubfs/4147179/technical_documents/service_instructions/sim20-107.pdf?t=1535754703082

[N231BN]

If increasing the idle mixture didn't help then the unmetered pressure is too low. They either didn't set it correctly or their gauge isn't accurate. They need to get the engine good and hot for setting this. Running your boost pump on low during landing roll out will help.

 

 

[SantosDumont]

On 8/21/2018 at 11:44 AM, gsxrpilot said:

My 252 suffers from this malady as well. I've been told it's common to my TSIO360. I've never had it quit in the air, but it often quits while slowing on the runway or on the taxiway. A quick shot of prime or throttle will usually keep it running. I wonder if the windmilling prop is what keeps it from happening in the air?

I’ve been having the same issue with the non-turbo IO-360-ES.  Setting it just above idoe or throwing on the boost pump resolves the issue. 

[Brian Stuart]

Thanks for all your replies.  We have done some test flying (after doing 97-3G) and found that the engine wanted to quit again at the end of the landing roll once hot. The RPM dropped to 300 before applying the low boost pump.  The engine immediately returned to the correct idle speed and ran with the pump running, albeit a little bit lumpy.  We did some more circuits and turned the low boost pump on during short final and all went well with the engine not wanting to quit.  I wonder why this engine in a Mooney does not require any fuel pumps on during takeoff and landing but the same engine in a Cirrus or Bonanza does require you to use fuel pump.  Some of the replies earlier in this thread mention that they use the low boost pump during landing.  I would appreciate any comments to the above issues.  At this stage I will use low boost pump on final through to end of taxi.  Can anyone see anything wrong with this procedure given that it is outside the Mooney POH?

Brian

 

[carusoam]

Brian,

1) update your avatar with what plane you are talking about... some people can’t remember all the details after a while.

2) Some planes have automated fuel pump systems... that come on at full throttle....  check your POH details for this...

3) Some electric fuel pumps have a fuel pump controller. That wears out over time.... burns out?

4) Sounds like you may be experiencing a fuel pump issue...

5) the controller part, may be for the Lo setting only...

6) I am probably adding details that are not related to your plane or problem, from fuzzy old memory.

7) Either way... the O has a fuel pump that comes on at FT during T/O.... not sure what turns it off

8) there is no fuel pump on for the landing/go around phase.... because of the automation...

9) nice details, @M20Doc !!!

PP thoughts and fuzzy memories... not a mechanic...

 

Best regards,

-a-

[N231BN]

Many thanks to all for your replies.  It appears that the problem lies in the 3 idle adjustments.  I have had the fuel system reset to TCM 97-3G and it was no better.  At idle it stalled immediately upon leaning which to me showed it as too lean at idle.  My LAME (AP?) then richened up the idle to show a 50 RPM rise on idle leaning.  I then flew for 1.5 hours and upon landing the engine failed to response to small power increases.  I kept introducing power until FF and then it lagged for 1-2 seconds before responding.  I then returned home and landed and it did the same thing.  No response to small (vernier) power increases and only responding to FF which resulted in 2 landings in 1.  This has rendered the aircraft unserviceable and I am getting frustrated.  My AP is not keen on doing anything outside 97-3G but I still have the same problem so there has to be some contributing factor/s.  I will take your replies back to my AP and see how he responds to the above information.  Any help is greatly appreciated.
Thanks Brian.  

When you say "FF" what are you referring to? Firewall forward?

[carusoam]

FF... fuel flow....

-a-

[Brian Stuart]

Thanks N231BN for your thoughtful reply.  The plane is a 2005 Ovation GX2.  It has done 950 hours and lives at Caboolture, Queensland, Australia.  I will update my avatar.

Cheers,

Brian

[N231BN]

FF... fuel flow....
-a-

That's the obvious answer but it doesn't make sense in this context. "I kept increasing throttle until FF..." Just trying to understand.