Need help diagnosing a starting problem

[Matt Ward]

Hey guys,

I need some help diagnosing a starting problem in my 1966 M20E (IO-360-A1A).  Key components are:

-newly overhauled Interav alternator (5 hours of use)

-Concorde RG-35AXC (less than 100 hours, 4 months)

-X Drive LH Solenoid starter (300 hours, 8 years)

-starter contractor (500 hours, 10 years)

-original shower of sparks system

My problems are recently worse, seeming to coincide with a new alternator after an in-flight alternator failure, and happen with hot, warm, and cold starts.  While I am sure my technique is not perfect, my goal with this post is to identify potential hardware issues.  Since the new alternator, the JPI is reporting voltage of 13.8 to 14.1 consistently.

The starting problem from today went like this, and it's pretty typical:

-cold start didn't catch after 2 times

-go to flooded start, engine floods, try flooded start procedure several times

-may or may not get a cough, may or may not get an attempt at running, never get enough of an attempt for me to take my hand off the key and start doing the air/mixture dance

-after trying variants of that flooded procedure 6 to 7 times, with 1 minute or so in between attempts, prop seems to start turning a  little slower, coughing becomes less frequent

-lineman today brought over his truck, hooked up to my battery, boosted it for about 10 minutes.  

-left his truck hooked up to my battery while I attempted to crank with the flooded procedure, fired almost instantly

So this is what I'm left wondering:

-after replacing the alternator, has it been unable to re-charge the "cranking amps" side of the battery, even after 2.5 hours of flying?  Is my problem that I need to recharge my battery?

-is it possible I destroyed my battery this fast due to a dying alternator?

-the starter does turn the prop but I'm suspect of it (for no rational reason other than its age) - is there any way to tell for sure my starter isn't the problem?

-the shower of sparks does buzz and my A&P thinks it's ok but I'm keep hearing about Mooney drivers going to the Slick starting system.  Does that sound like it would be appropriate for this situation?

Thanks for any insight you guys can provide, this is driving my crazy!  I want to get to a point where I never have to worry about getting it started hot, warm, or cold.

 

[carusoam]

1) Battery capacity check will solve the problem of not knowing what has happened in the last four months/100 hours...new Concorde’s are less likely to be a problem...

2) Struggling that much, not getting it started... then have it start when the truck is attached to it...
 

3) what technique are you using to prime the engine the first time?

4) from pump on to starter on... how much time did you wait for fuel to evaporate?

5) How ancient is the SOS box?  Have you researched the details about how to know when it needs an OH?

6) Do you need an excuse reason to get an electronic mag? 

7) If you have a proper technique... what’s left? Everything ignition related...mags, wire, plugs...

8) If you are not sure of the proper technique... rent a CFI...

9) If the starter works... the relay is Adequate... How old is the starter’s relay (solenoid, contactor, and contractor in Siri speak)

10) What spark plugs do you have? How old are they? If Champion have you measured their resistance?

11) Charging the Concorde with the right battery charger will pretty much take the charging system out of the suspect mix...

12) What is draining the battery between flights? How many weeks between flights?

13) how many blades go by during each start attempt?

14) how many go by on a successful start attempt? Two, four?

15) what is the X-drive referred to above?

16) Looks like the only unknown not covered is the SOS health... and tuning the technique...

17) SOS audible buzz means it is at least half working... it doesn’t mean much more...

18) There is an SOS manual around here somewhere...

PP thoughts only, not a mechanic...

Best regards,

-a-

[Matt Ward]

Thanks for the questions, I'll try to address what I can.  And I will run a battery capacity check, really surprised if that's the problem.

3) what technique are you using to prime the engine the first time?
Following the standard Mooney procedure outlined here http://www.mooneypilots.com/mapalog/HOT STARTS.htm

4) from pump on to starter on... how much time did you wait for fuel to evaporate?
On cold start, I typically run the pump 4-5 seconds, enough time to see the fuel pressure gauge move to the middle of the green.  Then pump off and try to crank within 3-5 seconds, I'd guess.

5) How ancient is the SOS box?  Have you researched the details about how to know when it needs an OH?
As far as I know, it's from 1966.  I've found the one Don Maxwell article on the subject but haven't done the procedure yet. https://www.donmaxwell.com/shower-of-sparks 

6) Do you need an excuse reason to get an electronic mag?
No!  I just had both mags go through their 500.

9) If the starter works... the relay is Adequate... How old is the starter’s relay (solenoid, contactor, and contractor in Siri speak)
I included the dates/age I have above.  My question is more basic in that is a starter really that binary: works or doesn't work?  Mine does turn the prop, is that good enough?

10) What spark plugs do you have? How old are they? If Champion have you measured their resistance?
They were just checked in annual and determined to be good, but I don't have more info than that.  No engine data from the JPI leads me to believe I have a spark plug problem.

12) What is draining the battery between flights? How many weeks between flights?
I can't imagine anything is draining the battery.  When I turn on the master with the engine off, the JPI reports > 12v after sitting for a few days.  I fly the plane a lot - 100 hours since April.  The plane flies at least once a week, probably an average of 2.

13) how many blades go by during each start attempt?
When it starts, it usually starts pretty quickly - I'd guess 15 or fewer.  When it doesn't start, I probably am guilty of holding on the starter too long sometimes, maybe 40.

14) how many go by on a successful start attempt? Two, four?
I don't see that few, but maybe a great start is 10 or so.

15) what is the X-drive referred to above?
It's the starter, referenced here: https://www.aircraftspruce.com/catalog/eppages/kellyxDrive.php  There was a part number change from SRZ-9022 to MZ-622.

16) Looks like the only unknown not covered is the SOS health... and tuning the technique...
I agree.  If the capacity checks out fine it's may be one of those items, maybe both!  I had my A&P look at the SOS and he remarked it was fine but I'm not honestly not sure exactly what he did.

17) SOS audible buzz means it is at least half working... it doesn’t mean much more...
I can confirm there is a buzz.  If I felt like going to the Slickstart would solve my problem, I'd do that immediately.

18) There is an SOS manual around here somewhere...
I think I've seen it, too, but the Maxwell article above may be more helpful for me.

[M20F]

None of what you are describing sounds like a starter issue.  The starter spins the prop around.   If it is doing that at the same speed as previously then it isn’t the starter. 
 

Sounds like either a spark or a fuel issue.  

[neilpilot]

5 minutes ago, Matt Ward said:

Post title should have said “starting” instead of “starter”

Go ahead and make that change 

[jaylw314]

You left out the ignition side of the equation.  Mags, harness, spark plugs?

A battery capacity test makes sense, but I suspect it's not the problem if you're seeing 14.0V on the bus voltage in flight.  The battery should be getting fully charged at that voltage.

Having a booster hooked up while successfully starting doesn't prove you have a bad battery.  It may simply be that a booster power supply adds additional cranking amps and spins the starter faster than would be expected.  If you have a weakness in the ignition system, that faster starter RPM (that you would never get even with a good battery) would simply make up for it.

[Matt Ward]

47 minutes ago, jaylw314 said:

You left out the ignition side of the equation.  Mags, harness, spark plugs?

A battery capacity test makes sense, but I suspect it's not the problem if you're seeing 14.0V on the bus voltage in flight.  The battery should be getting fully charged at that voltage.

Having a booster hooked up while successfully starting doesn't prove you have a bad battery.  It may simply be that a booster power supply adds additional cranking amps and spins the starter faster than would be expected.  If you have a weakness in the ignition system, that faster starter RPM (that you would never get even with a good battery) would simply make up for it.

I took the battery out of the plane and am charging it overnight on my charger just to be sure.  It's pretty new so I'll be surprised.

Each of the mags just went through a 500 hour inspection.  The plugs were checked at the annual (June) but I'm not sure of gaps.  When we pulled them they all looked good, at least in terms of oil/burn, for what that's worth.  I'm unaware of the age of the mag harness and can't find it in the logbooks anywhere.

Nothing in my Savvy data screams mag problem either, but maybe I’m not looking in the right places. 

[Matt Ward]

3 hours ago, carusoam said:

There is an SOS manual around here somewhere...

I think it’s here: https://www.csobeech.com/files/TCMIgnitionVibratorManual.pdf 

[Mooneymite]

19 minutes ago, Matt Ward said:

I think it’s here: https://www.csobeech.com/files/TCMIgnitionVibratorManual.pdf 

Try:  https://www.donmaxwell.com/shower-of-sparks

[carusoam]

Anything written by...

• David McGee
• DMax

Is going to be solid Mooney advice...
 

Expect a good start to happen in two to four blades...

10 blades going by is a typical... not getting the mixture right...as the fuel gets thrown out the exhaust valve... the mixture is changing... When the mixture is right it fires off...

If not enough prime is used... or not enough time to evaporate... lots of blades are going to go by... and the intake is dry of fuel and getting dryer...
 

When the plane is new to you... it is normal to experiment with the number of seconds to use with the prime step...

For my plane... it takes a second or two to have fuel reach the FF sensor...

My engine is also sensitive to where the throttle is, and of course the mixture knob position...

Doing it the same way every time is a good way to approach the challenge...

If your procedure says push the throttle all the way in first... Do it! or the fuel will not flow the same way....

Often, we are so afraid of over priming... we under prime and get disappointed when nothing happens...

 

If 10blades have gone by... the prime is probably gone too... if you are lucky enough to get a start... that’s because the engine is delivering enough fuel to start...
 

If you are counting forty blades going by... you are heating the starter...  read up on proper cooling off periods for your starter...

Step wise approach...

Start with four seconds of fuel, wait ten seconds for the fuel to evaporate... hit the starter... four blades go by... 

Add a couple of seconds more, wait ten seconds for the fuel to evaporate... hit the starter... four blades go by...

If everything is working... it will start and you will get a feeling for where to begin the next time...

four seconds, six seconds, eight seconds...

Once flooded, pull the mixture back...

When doing the flooded start, does it get any better...? Or is it really lucky to get started this way as well?

 

Signs the left mag (the one we start with) isn’t working properly... let off the key while the blades are going by... does the engine suddenly start or fire off a cylinder or two?

The R mag suddenly comes on line when we let off the key...

The Lmag has the second set of points set at TDC... if this set of points isn’t working... the start is not going to happen...

 

1) Check the behavior of the Lmag’s starting points... the ones timed for TDC...

2) Check the SOS’s output as per DMax...

3) Check the spark plugs for type... written in your logs... are they Champion?

4) If Champion, measure their resistance... There is a spec for this... when they don’t meet spec... it is really easy to measure....

5) Starting is such a dynamic situation, very much unrelated to ordinary engine running....

6) To see mag health... post the JPI graphs, get a good look at the run-up, do an inflight mag test... see what falls out...

7) Reviewing the starter vibrator docs above... there are a few parts in the box that can be sensitive to heat and vibration over the decades... it is quite possible the spark is not as strong as it wants to be...

8) If the flooded start always works...  that’s a sign the regular start isn’t getting enough fuel...

9) If the flooded start doesn’t work any better... probably a sign the ignition system needs some help...

10) mags just got OH’d... good.

11) go through the efforts required to define everything as an individual is working properly...

12) Week sparks are selling many electronic mags lately, just for the starting procedure...

 

PP thoughts for discussion purposes only, not mechanical solutions...

Best regards,

-a-

[Ragsf15e]

If it’s cold and you have to use other than normal start procedures (ie flooding it) more than occasionally, something is definitely wrong with the engine or your procedure.  If the engine is turning over more than just barely, it’s not the likely the battery.  We all want the starter to turn so fast that we can taxi behind it, but it should start with a more normal rpm.

 I know you said you just had everything checked/annual, but pulling a couple plugs on the left mag and checking them is easy and probably informative.  Are there deposits or fouling?  Other places to check are Left mag timing, wiring, and sos.

Finally, if you prime it and it doesn’t start, there’s a reasonable chance you didn’t add enough fuel, so nothing wrong with priming again and attempting same start.  You can always flood it, but that should be a last resort.
 

 

[M20F]

18 hours ago, Matt Ward said:

Each of the mags just went through a 500 hour inspection.  The plugs were checked at the annual (June) but I'm not sure of gaps. 

When troubleshooting a problem I like to first start and check all the cheapest and easiest things.  When that fails I think to myself the airplane should operate the same today as it did yesterday +/- anything different.  
 
Thus if you have checked simple things my thoughts would be an issue with the plugs from the annual (they were touched thus now different, do not assume they got touched correctly).  Then next would be timing and mags, they got overhauled and reinstalled so again they are different. 
 
It certainly could be something random but my experience over the years with overhauled or fixed things is people make mistakes (even Don Maxwell).  So check the things that got touched recently and go cheapest to most expensive. 

[Yetti]

A1A start

Cold.

1. Throttle 1" open. mixture closed.

2 Pump on

3 Open mixture full

4. count to 6 a bit longer if plane has been sitting or cold.

5. Close mixture.

Pump off

Crank.

Feed mixture slowly when pops. I don't even go to full rich.  Just 1/3 open

Set RPM to 1100 - 1200

Hot start

Shut down with mixture at 1100rpm

Don't touch anything.

Just crank.

Feed mixture when pops.

 

Flooded.

How do you know it is flooded.  When it pops and you feed mixture and it dies.

Throttle full open.

Crank.

Be ready to do two handed dance when pops.  pull throttle back and feed mixture.

 

[N231BN]

It sure sounds like you have a SOS issue, either in the box itself, the wiring, or the retard points. Both mags are grounded while starting so RPM should make no difference and if you had plug or harness issues they would show up on a mag check or in flight.

 

It is possible that the increased voltage by being jump-started helped your weak SOS system.

 

[M20F]

https://www.donmaxwell.com/shower-of-sparks

[carusoam]

Two + votes for the DMax paper for the SOS...(above, Gus and Mike)

1/2 of a vote for where Matt Found the article for himself... 

Best regards,

-a-

[carusoam]

Let’s say the SOS proves to be weak and needs replacement...

What would be the best next step...

Forward thinking only, not hiding an agenda or anything...

PP thoughts only, not a mechanic...

Best regards,

-a-

[Yetti]

13 hours ago, N231BN said:

It sure sounds like you have a SOS issue, either in the box itself, the wiring, or the retard points. Both mags are grounded while starting so RPM should make no difference and if you had plug or harness issues they would show up on a mag check or in flight.

 

It is possible that the increased voltage by being jump-started helped your weak SOS system.

 

The ignition key is pushed inward to activate the starter. At the same time, the ignition switch internally grounds the right magneto so it will not operate.

[Mooneymite]

15 minutes ago, carusoam said:

Let’s say the SOS proves to be weak and needs replacement...

What would be the best next step...

-a-

SOS is really a simple box.  If it's buzzing, but not sparking, try replacing the capacitor and the points.  When I did mine years ago, Aviall had the parts...cheap.

[N231BN]

The ignition key is pushed inward to activate the starter. At the same time, the ignition switch internally grounds the right magneto so it will not operate.

With a shower of sparks system both P-leads are grounded in the "start" position.

[Matt Ward]

1 hour ago, carusoam said:

Let’s say the SOS proves to be weak and needs replacement...

What would be the best next step...

Forward thinking only, not hiding an agenda or anything...

PP thoughts only, not a mechanic...

Best regards,

-a-

So @Vance Harral was gracious enough to go flying with me tonight to try to diagnose this.  My goal was to eliminate 1) starter issues, 2) SOS issues, and/or 3) pilot issues.  The starter is turning reasonably fast and we eliminated that.  My technique was reasonable although Vance did dial me in.  My next step is to try to diagnose the SOS issue as we both think that could be the issue.  The Maxwell article describes a relatively straightforward way to observe the spark.  If the spark does indeed appear weak, I'll be facing 1) overhaul the SOS, or 2) install the Slickstart.

[Yetti]

56 minutes ago, N231BN said:

1 hour ago, Yetti said:

The ignition key is pushed inward to activate the starter. At the same time, the ignition switch internally grounds the right magneto so it will not operate.

With a shower of sparks system both P-leads are grounded in the "start" position.

I cut and paste from the Maxwell article.  Should have put quotes around it.

[Ragsf15e]

18 minutes ago, Matt Ward said:

So @Vance Harral was gracious enough to go flying with me tonight to try to diagnose this.  My goal was to eliminate 1) starter issues, 2) SOS issues, and/or 3) pilot issues.  The starter is turning reasonably fast and we eliminated that.  My technique was reasonable although Vance did dial me in.  My next step is to try to diagnose the SOS issue as we both think that could be the issue.  The Maxwell article describes a relatively straightforward way to observe the spark.  If the spark does indeed appear weak, I'll be facing 1) overhaul the SOS, or 2) install the Slickstart.

IF it does end up being the SOS, it may not cost much.  If it starts to add up though, a Surefly mag is an option as you no longer need the sos.  You can keep your newly oh spare mag on the shelf or sell it.

[N231BN]

I cut and paste from the Maxwell article.  Should have put quotes around it.

That's okay, he goes on to say: "The ignition switch also selects the “retard points” and disables the normal points in the left magneto."

​The simple version is both P-leads are grounded and the buzz box sends a voltage pulse to the retard points.

[carusoam]

23 minutes ago, Matt Ward said:

So @Vance Harral was gracious enough to go flying with me tonight to try to diagnose this.  My goal was to eliminate 1) starter issues, 2) SOS issues, and/or 3) pilot issues.  The starter is turning reasonably fast and we eliminated that.  My technique was reasonable although Vance did dial me in.  My next step is to try to diagnose the SOS issue as we both think that could be the issue.  The Maxwell article describes a relatively straightforward way to observe the spark.  If the spark does indeed appear weak, I'll be facing 1) overhaul the SOS, or 2) install the Slickstart.

 

Way to go Vance!

 

Stand up MSer of the day!

 

Go MS!

Best regards,

-a-