Engine Idle Issue

[Johnvmorgan2001]

My Mooney 252 (TSIO 360MB) has a strange idle issue. When I land after a flight, the engine quits just before I turn off the runway. If I keep the idle at 1000 RPM or above it doesn't quit. Additionally, when I turn left or right the engine wants to quit too. So the side force of turning left or right or stopping seem to make the engine quit! What could this be?  Anyone with similar experience? My guess is it's either the fuel pump, fuel servo, or the spider. 

[bonal]

Welcome John M, if you install a more accurate fuel gauge it will fix the problem. See other thread and obviously just kidding. Informed answers soon to follow. As always to the new guy pictures please.

[Pictreed]

That's not right bonal. Lol

My E almost dies to so I have to lean it back a bit and give it a bit of throttle.  

[Marauder]

1 hour ago, bonal said:

Welcome John M, if you install a more accurate fuel gauge it will fix the problem. See other thread and obviously just kidding. Informed answers soon to follow. As always to the new guy pictures please.

Now that is some funny stuff!

Regards,

Bad "ju ju" Marauder

John -- How much fuel is in the tank? I know there was some un-porting issues with some models of Mooneys (it might be the Rocket/Missiles). The fuel system should be pressurized at all times, do you see any pressure drops when this happens? If so, it could be a problem with the engine driven fuel pump. Does it do it with the boost pump on?

[carusoam]

What rpm reading do you have with the throttle pulled all the way out?

sometimes this setting gets reset at annual.  Weather and temperatures might be different.

Typically, the idle rpm is set as low as possible to minimize float during the landing phase.  Unfortunately the rpm may not be enough to continue to turn the engine after landing.

PP ideas only, I am not a mechanic.

Welcome aboard,

-a-

[Jeff H.]

I have a Rocket, not a 252, so your mileage may vary as the kids say  . . . 

Check your climb temperatures - if a little high the issue may be require the fuel injection system to be re-balanced.  Too lean at max throttle and too rich at low throttle.  Check for any engine service bulletins related to the fuel injection system as a guide for your AP to diagnose the issue.

And the above may not apply - just threads to pull to find a resolution.  For me, I have to lean about a fingers width in the pattern to avoid stumbling and engine quitting on roll out.  Still working on the FI issues . . . Sigh.

Jeff

[Johnvmorgan2001]

Thanks all.

Even when it is leaned out during/after landing, when I turn left or right, it wants to quit.  Even when it's leaned out and at 900 rpm or more.

It's strange and results in long landings/rollouts if I keep 1000 rpm on touchdown.

Some other data: When I first bought the plane (about 12 months ago) it had this problem and the pretty knowledgeable Mooney mechanic spent a lot of time adjusting the hi and low idle fuel pressure. But he didn't really fix the issue.

Also, the engine runs a bit rich at full power (28.5 gph or so vs book at 24.5 gph) but it seems like many Mooney M20k/TSIO 360MBs have this same issue. I just lean it out a tad on TO. 

The idle is set high now at 900 rpm (vs 700, which I think is standard) so it doesn't stall out...even though it still when I turn unless I pop up the throttle to 1000.

The engine temp on climb out and cruise are just fine...not too hot or cold.

[PMcClure]

I was having the same issue on my IO 550. I flew it to TCM in Fairhope and had them adjust the fuel system pressures. Problem solved. Prior to that I had several mechanics monkey around with the fuel systems. Evidently they didn't do it right. 

[carusoam]

John, 

When you get a chance...  Update your data in your avatar.  This will help readers match your data with your plane/engine type.

there is a document that defines FF at max power... The TDC(?) you may want to compare what you are seeing to what it is supposed to be.  Leaning for T/O is not usually in the procedures.  When it is done it is usually done with respect to an EGT. So leaning a 'tad' is indicating something amiss...?

700rpm is typical for Mooneys.  900rpm would keep them floating for a long time...

As PMc has pointed out...  Work with your mechanic to find out what these settings are supposed to be and then get them adjusted properly.

Stuff they didn't tell you about in the usual flying lessons...  

Trying to be helpful.

Best regards,

-a-

[Johnvmorgan2001]

2 hours ago, PMcClure said:

I was having the same issue on my IO 550. I flew it to TCM in Fairhope and had them adjust the fuel system pressures. Problem solved. Prior to that I had several mechanics monkey around with the fuel systems. Evidently they didn't do it right. 

Would your plane quit when you were turning on the ground?  I don't understand why the side-load created when turning would cause the engine to want to quit.

[Jim F]

Hi John,

this sounds like your fuel injection is not set correctly. SID97-3C should be followed. 

A would have the fuel injection nozzles cleaned and pressured check the intake system to look for air leaks before the fuel system is adjusted. The TCM fuel system is very simple and proper adjustment is critical. I have set a lot of TCM fuel systems and on TSIO-360s after setting the unmetered fuel pressure I set takeoff power to the Max fuel on the SID. Your engine is 23.0GPH. You also need to know if your tach is correct because RPM is important. This allows for a little extra cooling on hot days. Carusoam is correct the idel speed needs to be at the minimum so you don't float.  I set my idel mixture to 30RPM rich of peak at 700RPM.  The side load thing doesn't sound right.  After you do the above find a wide taxiway and taxi full right turn to full left turn and see what happens.

When it's set right everything works well  

jim

[Johnvmorgan2001]

Thanks Jim.  Does the spider, servo or fuel pump have anything in it that would mechanically be influenced with some side load pressure?  My spider, servo and pump are rather old.

[Guest]

24 minutes ago, Johnvmorgan2001 said:

Thanks Jim.  Does the spider, servo or fuel pump have anything in it that would mechanically be influenced with some side load pressure?  My spider, servo and pump are rather old.

The current version of the TCM SID 97-3 is now G.  If you maintainer does not have accurate gauges and a good understanding of the set up procedures take it and him to someone who does.  The TCM factory would be good if you're close to them.  TCM used to publish a bunch of books which explained turbo charging and fuel injection, search their web site and you may find them.

Clarence

[Jim F]

Thanks Clearance. 

John, I have seen many engines not run well or die on roll out and proper setting of fuel flows fixed the problem. Find a shop that does fuel flows routinely and has the equipment. If the fuel flows don't fix the problem then you can look further. 

Jim

[Johnvmorgan2001]

Thanks guys. I really appreciate it.

I will find a mechanic who can do that SID 97 correctly and I will be optimistic that it will solve my problem.

[PMcClure]

17 hours ago, Johnvmorgan2001 said:

Would your plane quit when you were turning on the ground?  I don't understand why the side-load created when turning would cause the engine to want to quit.

Only on roll out, and about at the turn off. Never noticed it in taxi. 

[Pepperjet]

Some interesting answers above.  However, the gyroscopic effect dragging down the prop while turning off the runway, having mixture too lean, at less than 700 rpm may certainly stall the motor.  Especially if the turn is abrupt and at greater than 45 degrees.  Best practice is to not lean the motor until off the runway and keep rpm no lower than 700 to 800 during turn.

[Pepperjet]

On 1/27/2022 at 3:34 PM, carusoam said:

I think the discussion is in regards to leaning on the ground after start-up…  prior to departure…

 

Usual discussion applies…. Touch nothing until off the runway…. 
 

Some people like to raise flaps, at the risk of using the wrong lever….

When forgetting to push the mixture all the way in…. You first get a hint the engine isn’t running as you slow down on the runway…

Then again…   Holy Ghost of a thread dig up!

Great experience shared!

-a-

 

Perhaps a closer look at what Johnvmorgan2001 said to start this post may be in order.  First post, second sentence, "When I land after a flight, the engine quits just before I turn off the runway."  Appears the discussion has little to do with "leaning on the ground after start-up... prior to departure..."  Agreed, some good responses indeed.

[carusoam]

On 2/23/2022 at 1:00 AM, Pepperjet said:

Perhaps a closer look at what Johnvmorgan2001 said to start this post may be in order.  First post, second sentence, "When I land after a flight, the engine quits just before I turn off the runway."  Appears the discussion has little to do with "leaning on the ground after start-up... prior to departure..."  Agreed, some good responses indeed.

Thanks PepperJ!

I’m not sure my response was to this thread…. 
 

It just showed up here…

I appreciate the kind response…

..and I gave the thread a complete and thorough reading this time…  

Thanks and best regards,

-a-

[Guest]

On 1/26/2022 at 10:44 PM, Pepperjet said:

Some interesting answers above.  However, the gyroscopic effect dragging down the prop while turning off the runway, having mixture too lean, at less than 700 rpm may certainly stall the motor.  Especially if the turn is abrupt and at greater than 45 degrees.  Best practice is to not lean the motor until off the runway and keep rpm no lower than 700 to 800 during turn.

Never heard of gyroscopic effect causing an engine to quit at idle, can you explain?  Improper fuel system set causes engines to idle poorly and quit on roll out, and overheat in climb.

Clarence

[Hank]

On 1/26/2022 at 9:44 PM, Pepperjet said:

Some interesting answers above.  However, the gyroscopic effect dragging down the prop while turning off the runway, having mixture too lean, at less than 700 rpm may certainly stall the motor.  Especially if the turn is abrupt and at greater than 45 degrees.  Best practice is to not lean the motor until off the runway and keep rpm no lower than 700 to 800 during turn.

Never heard this before.

All of my training (PPL and Instrument) plus 7-1/2 years of Mooney ownership were at a 3000' field with no taxiway, forcing a 180° turn for each takeoff and each landing, every time with the throttle all the way out and rudder pedal to the floor. That's how I know that my plane turns tighter to the right than to the left, even with a touch of throttle mid-turn to keep the plane moving (not to keep the prop turning).

Do I need to rush out and buy a lottery ticket? Strange how none of the ones I've already bought have won anything . . .

I did learn, after several years' flying my Mooney, to not pull a Cessna throttle to idle on roll out, those things quit! My little Lycoming purrs along at idle from short final until I leave the runway, and flaps comfortably raise while holding the throttle out on roll out, often before I slow to my 50 mph braking speed.

[A64Pilot]

1 hour ago, M20Doc said:

Never heard of gyroscopic effect causing an engine to quit at idle, can you explain?  Improper fuel system set causes engines to idle poorly and quit on roll out, and overheat in climb.

Clarence

I doubt the gyro effect too, I used to spin tail wheels around quickly, much quicker than possible for a nose dragger and it didn’t decay idle RPM.

It was pointed out to me that doing so might be bad for the engine bearings so I don’t anymore.

Point of the quick spin was to turn the aircraft 180 without prop blasting the hangar.

[Ryan Carvajal]

Hello Guys. Did you ever fixed this Idle Issue. It happing to me M20K 252. And we already check the fuel pressure in high and low 

[Z W]

Many of us have had similar issues.

First, I'd check your air intake plenum boot (the one that goes from your lower cowl to your air filter housing).  Make sure it's properly installed, not torn or ripped, and not choking off your engine's air intake.  You can verify by removing the access panel to it on the copilot side of the lower cowl.  I've had it installed wrong and repaired wrong by shops.  A clue will be your alternate air light coming on at high power.  And the engine will not run right without proper air flow.

If you're getting good air intake, the problem is usually related to the fuel system setup.  You need a good mechanic with proper gauges to perform the whole setup as set out in SID97-3G, which is now actually a part of Continental's M0 maintenance manual but the steps remain the same.  I've attached a copy.

They can't just "check the fuel pressure in high and low".  It has to be set up in a certain order and tested with the cowl on which is a little tedious.  You need accurate fuel flow and RPM gauges.  In my experience many mechanics do not have the tools or the knowledge to do this.  The 252 engine is particularly finicky and hard to get right, but runs great when set up properly.

Don Maxwell fixed mine the last time someone else messed it up.  I'd recommend taking the plane there or to someone who has set up the TSIO-360-MB engine before.

SID97-3G - Continuous Flow Fuel Injection Systems Adjustment Specs and Instructions.pdf