Strange starter issue and other first time owner issues

[druidjaidan]

After much delay my partner and I finally closed on N9391M last week.  We picker her up from Placerville and flew her back to her knew home at KPAE.  As seems to be par for the course, despite a thorough pre buy at LASAR the return trip resulted in a laundry list of squawks =(, mostly lesser used avionics and features that we will work on soon.  But also some that we may have to deal with very soon.  Both the landing light and the nav lights popped the breaker/switch on the return flight.  It was weird because the nav lights would stay on for 5-30min and the landing light on for maybe 5 minutes.  Didn't seem like they were shorting since that would go quick.  Trying to save a buck so any ideas for diagnosing it before we pay a shop to diagnose it would be appreciated.

One of the things that's been nagging at me though is the start process.  No matter the process we did it seemed like the engine would not catch until the moment we released the starter.  The starter turns the prop strongly and we hear buzzing from the vibrator when we push the starter in.  Is there anything we should try, or chock it up to fuel injected planes are weird.  Both my partner and I have flown extensively in fuel injected planes, and have never seen anything like that.

[75_M20F]

My 75 M20F became almost impossible to start a while back. You would have to try 4 or 5 times to start it and sometimes it would kick back too.The shop first tried sending the fuel servo out for overhaul, that did not fix the issue in my case. Turned out to be an issue with the Mags. Had the Mags and wires replaced and it fixed the issue.

[druidjaidan]

I'm personally kinda leaning toward the shower of sparks system.  I read this after I posted and it describes exactly what we were seeing.  Guess we'll get it into the shop to get it fixed.

http://www.donmaxwell.com/publications/MAPA_TEXT/Shower%20of%20Sparks/Shower%20of%20Sparks.htm

[N7186V]

Same thing was happening when I bought my '75F.  In my case, the previous owner had some mods done and the wiring diagrams weren't followed properly.  I wish I could tell you exactly what it was that was wrong, but a lot of wiring was removed and rerouted.

[N601RX]

The light issues are most likely weak circuit breakers, loose screw on the breaker or corrosion between the buss bar and circuit breaker. 

Starting issue could be either shower of sparks or mag. 

[jamesm]

As  N601X stated I can attested to switch/circuit breaker being bad.  a few annual back I was doing op's check on the lights  on a '67C.  so I would reach in through pilot's window to turn on nav lights on and the nav lights came on.  Later during  the annual my IA climbed up on the wing and turned on  the nav light  as he getting out of airplane the switch/circuit breaker tripped. The mechanical spring in the switch/circuit breaker had started to fail. If you have the original switch/circuit breakers, You  may consider replacing all switch/circuit breakers.  Because  if you try to replace one or two the original switch/circuit breakers it will cost you considerably  more , If I recall correctly it was some where around $130 for one replacement  for  the original  switch/circuit breakers ( about 2 to 3 years ago)  . You can probably replace all the original switch/circuit breakers equivalent switch/circuit breaker about ~$32 to ~$47. Not to mention  there is a buss bar the that ties all the switch/circuit breakers together for the power side of the breaker and it won't line up mounting holes in the instrument panel. It is all or nothing kind of deal  you will have to match what circuit breaker  have you have installed or replace all the circuit breakers.  if you have buss bar part installed. If  your wiring is the original it is not too uncommon for the wiring  terminations  tend to fatigue over time and need  to be re-crimped. Many years ago , I had the  "Cigar lighter/ Ignition" circuit breaker  go intermittent  on me it was bugger to find since often times cigar lighter connection was intermittent at times. 

http://www.aircraftspruce.com/catalog/elpages/pbcircuitbrkr2.php 

For the starting problem(s)....

Just curios what kind of starter do you have ?

Possible mag timing to engine (though LASAR probably would have found it)

This may not apply to your  model Mooney  someone on this site posted Don Maxwell's  technique for a M20J model. something to consider if you have fuel injection.

https://www.youtube.com/watch?v=jbRYqS-fRo0

 

 Hope this helps,

James '67C

 

[kortopates]

I'm personally kinda leaning toward the shower of sparks system.  I read this after I posted and it describes exactly what we were seeing.  Guess we'll get it into the shop to get it fixed.

http://www.donmaxwell.com/publications/MAPA_TEXT/Shower%20of%20Sparks/Shower%20of%20Sparks.htm

I am sure your starting issue is exactly your SOS system since it starts only when it goes out of start mode into both mode - and pretty typical.

I wouldn't fret over the pre-buy not finding these things since there is no such thing as a thorough pre-buy - that would be called an Annual and even then it's not likely to find the lights issue since it didn't pop right away. However you'd think your test flight would have revealed the starting issue and even the light issue - I know it's frustrating but these won't slow you down much in the grand scheme of things.

Welcome to airplane ownership! Overall you should find it very fulfilling.

Sent from my iPhone using Tapatalk

[Yetti]

So C mooney?   For starter.  Mags or switch.   or mag wiring.   The left mag gets retarded via the second wire and the right gets grounded.  When were the mags last rebuilt?   If it was a while ago they can be timed right and the air gap still be off due to wear.  If they are over / near 500 hours get them rebuilt.

 

Are you running the landing light while in Cruise?  If so go LED about they same price as a switch.

[carusoam]

65 C experience...

1) weak shocks for the panel cause the panel to droop and hit the CBs switches.

2) old CBs do wear over time.  The landing light goes first.

3) the reason it costs less to swap out all the CBs at one time...   They are attached to one bus bar.  Taking out one CB requires disconnecting a bunch of them to remove the buss bar to reach the one offender.

best regards,

-a-

[druidjaidan]

We had a shop take a look at the starting issues.  They are thinking the starter vibrator is the issue and are prepping to send it out for overhaul.  Which all sounds fine to me.  However I got to take a look at the logs closer last night and I noticed that the previous owner had replaced it July 2014!  The mechanic also pulled the spark plugs, all fine waire champions all with excessively high resistance (20k ohm range).  He's recommending replacing them.

Trying to determine the best course of action.  It seems like replacing the plugs no matter what is the right call.  But should we do that before we send the vibrator in for overhaul or might that be the entire issue?  Could the high resistance spark plugs be causing the vibrator issue, and/or have damaged the vibrator?

[Mooneymite]

How many hours on the fine wire Champions?  Those are pricey plugs!!!!  I hope you got a lot of use out of them.

The starting vibrator is a pretty simple device.  As long as it's vibrating, there are probably only two things to be replaced:  the capacitor and the points.  Both easily bought and installed.  Somewhere in my files, I have the part numbers and source.

[druidjaidan]

18 hours ago, Mooneymite said:

How many hours on the fine wire Champions?  Those are pricey plugs!!!!  I hope you got a lot of use out of them.

The starting vibrator is a pretty simple device.  As long as it's vibrating, there are probably only two things to be replaced:  the capacitor and the points.  Both easily bought and installed.  Somewhere in my files, I have the part numbers and source.

We personally got very little use out of them .  There are no notes in the logs regarding the replacement of the spark plugs, so I assume they were original with the engine when it was last overhauled (~380 hours).  That said they are part of the "bad batch" of Champion plugs known for failing resistors.  My partner went out and tested them, some were as high as 80kohm.  We're planning to just replace them with Tempest massives and if we see fouling issues we'll upgrade to fine wires on the bottom.

If I had realized just how simple the vibrator was I would have just tested it out myself before sending out to be tested/overhauled if necessary.  It's just an LC circuit.

[Mooneymite]

10 minutes ago, druidjaidan said:

If I had realized just how simple the vibrator was I would have just tested it out myself before sending out to be tested/overhauled if necessary.  It's just an LC circuit.

When my shower of sparks went on the fritz I replaced the points which had been burned due to the bad capacitor, but someone told me, I could have just cleaned them up with an old fashioned automotive point file and probably done as well.  Might have been worth a try, but the new ones weren't very expensive.

[N601RX]

Replacing the parts in the Shower of sparks is no guarantee it will work.  The dwell has to be adjusted while connected to the mag.  You need an amp meter, adjustable spark gap and sos overhaul manual.  In addition to setting the gap you have to bend the arm the correct amount to get the coil current to an acceptable range.  I know from experience that after replacing the points and setting the gap that it will buzz normally but will not fire a plug.  After setting the dwell by bending the arm it came alive.  You can find the manual that describes the procedure on the CSOB site.

[N201MKTurbo]

I had that starting issue once and the lead to the retard breaker was shorted to the mag case inside the mag.

You can check this without taking off the mag. Remove the point cover and look to see if the retard breaker wire was laying against the side of the case, if it is it can wear the insulation off the wire and eventually short out. I fixed it by putting some small spiral wrap on the wire. A lot cheaper then a mag or sos overhaul.

[SpamPilot]

When I got my M20F, I also had starting problems.  I thought I would just have to learn to live with it, but on a trip to San Antonio the Mooney experts at Southwest Texas Aviation set me straight.  One mag needed to be both rebuilt and retimed, and the battery needed replacing.  Then my starting procedure needed finessing.  Now I can start the airplane reliably.

First, I almost never prime, but I do note the fuel line pressure, since it may still be high from the last time the engine was run.  Cold, and with no fuel pressure in the line, I leave the electric fuel pump off and set the mixture control to a midpoint roughly corresponding to the "leaned in cruise" point.  This means that as the mechanical fuel pump pressurizes the lines, the effective mixture during crank will start lean and slowly cross through the flammability limits range for gasoline.  (previously I had been starting full rich, which often would flood the engine)  Then I crank with patience.  At summer temperatures, she will usually fire up within five or six blades, but cooler temps can take a dozen blades.  Remember that two blades (one revolution) is the minimum for the first cylinder to take a gulp of fuel and air, which may not be an ignitable mixture, and compress it for ignition, and five blades is the minimum for all four cylinders to get their first shot at firing.  I keep cranking until the engine is confidently running on its own; this usually doesn't take long, it's just that if I release the key and the engine quits, the fuel in the (now pressurized) lines runs into the cylinders and she's flooded.  If the temps are dipping into the 30's, I'll use a richer mixture setting since the effective mixture will be leaner due to lack of vaporization.  If the temps are near freezing or below, I know I should be preheating the engine, but if that's not possible, then I'll prime by putting the mixture into fuel cutoff, turning on the fuel pump just long enough to pressurize the lines, then setting the mixture rich of "leaned in cruise" (remember to turn the pump off since the injectors are always pumping fuel when the electric fuel pump is on, even if the engine isn't running).  This dumps a charge of fuel into the intake.  I wait five seconds for vaporization, then crank as I usually do, with the electric fuel pump off.

If the engine is warm, the fuel lines will still be pressurized from the last time running.  Again I don't use the electric pump, but now I have the problem that as soon as I crack the mixture open, a bunch of fuel is going to get dumped into the engine.  This was my error when starting warm.  What I've found is that when warm (meaning the engine has been run within the past few hours), it will fire after a few blades with the mixture in idle cut-off, presumably due to residual fuel and a tiny amount of leakage from the injectors.  As soon as it starts firing, I move the mixture to the leaned-in-cruise point (but not full rich) and continue cranking with patience until I'm confident the engine can stay running on its own.

Others have developed their own starting procedures, with results promising two-blade starts at 20F every time.  I tried several recommended procedures that didn't work as reliably for me as the above, which I think says more about the variability of engine installations than the validity of the recommendations.  I have a Sky-Tec starter and a Power Flow exhaust, if that makes a difference.  So you should read those as well and experiment, just remember YMMV.

[Yetti]

Transition instructor fail proof starting method.

1. Throttle open an inch

2. Elec fuel pump on

3. Open mixture full

4. Count to 6 seconds

5. Close mixture

6. Fuel pump off

7 Crank engine.before you loose your prime.

Be ready on mixture

When starts pull back throttle to 1100

 

Hot start.

1. 1100 rpm for shut down

2. Don't touch anything

3. Crank engine

4. Be ready on mixture

Should start with about 5 blades.

 

What I learned.  How do you know when flooded?

When it fires and you advance mixture and it dies.   It is flooded.

Full throttle open.  No mixture

Crank

When catches. Not so fast with the mixture and pull the throttle back.

I tried what worked in the C172 and just ended up with fuel all over the ground.

 

[DrBill]

I had same issue after an annual.. Mechanic left the starting mag points TOO CLOSE. We (he and I) reset the points and timing and problem went away.

Bill

 

Edited January 25, 2016 by DrBill

[druidjaidan]

So I can give an update on what was up.  When we dug closer into the logs we found out the vibrator had been recently replaced (<1yr ago).  So we were shocked it would fail again.  The mechanic pulled it anyway, and lo and behold it was FULL of water.  Electronics + water = bad.  So how did this get missed in the prebuy?  Well the plane has spent most of it's life, including the past few years, in a hangar.  In that time the windshield seal had failed in one spot.  That spot was right above the point that the vibrator is mounted.  When it went for inspection with LASAR the vibrator worked fine so Paul didn't note it.  However, right after the inspection the broker picked up the plane and it sat on a ramp (uncovered...), for a month while the broker dealt with title issues.  About 6 days before we closed a major storm came through and thoroughly drenched the plane and destroyed the vibrator.  

We inspected the plane and found no other signs of water except draining straight into the vibrator.  So we overhauled the vibrator, replaced the plugs, and resealed the windshield.

It's unfortunate because it took up most of our after purchase reserve we had set aside for any initial squawks.  I would have liked to have had a few other less critical, but kinda annoying squawks taken care of that we are now going to wait on a few months.  The custom annunciator light panel doesn't dim at night, the 430 doesn't autodim for some reason, the landing light and nav light breaker/switches are worn out, the heater can't be fully turned off, and gear horn doesn't come on until idle, and the stall horn doesn't come on in flight.  It's quite a list =)

Edited January 25, 2016 by druidjaidan

[Guest]

Hard to call it airworthy.  Smoke in the cabin and you can't turn off the heater, gear horn not working and stall warning not working.

Clarence

[Yetti]

Heater is probably a lube/ cable adjustment. Front right firewall is where the slide valve is located.