Matronics Email Lists Forum Index Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
 
 Get Email Distribution Too!Get Email Distribution Too!    FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Starter problem analysis

 
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> AeroElectric-List
View previous topic :: View next topic  
Author Message
jm(at)10squaredcorp.com
Guest





PostPosted: Sat Mar 11, 2006 2:38 pm    Post subject: Starter problem analysis Reply with quote

I am trying to troubleshoot a problem with the starter on my Stinson.
The problem seems to occur only when the engine is hot. When the
engine is cold the engine turns over fine. When hot, the starter acts
like it's trying to turn and after multiple attempts it will finally
start turning over. I've read that this is a low voltage condition
and I've taken some voltage readings with the engine cold:

Prior to charging battery: 12.38 VDC at the terminals
After charging battery: 12.87 VDC at the terminals
Battery voltage at terminals while cranking: 10.4 VDC
Voltage across starter while cranking: 9.8 VDC
Voltage across master and starter solenoid while cranking: < 1 VDC

The ground connection consists of a cable from the battery to the
engine mount and from another engine mount point to the engine via a
ground strap.

I plan to take a meter and test leads with me to get some readings the
next time the problem arises, but do these readings indicate a
problem with the starter or battery?

I hope this is the right forum for this question, if not please
forgive the intrusion.

Thanks,

Jim


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
skywagon



Joined: 11 Feb 2006
Posts: 184

PostPosted: Sat Mar 11, 2006 3:36 pm    Post subject: Starter problem analysis Reply with quote

Jim,
I would suspicious that there is something worn, wrong with the
armature and or its bearings. Maybe, some part of windings are loose
and expand with heat such that it physically contacts the surrounding
structures. Could be just worn bearings that combined with run-out
allows the armature to partially jam when hot, but, just clears when
cold.
David
---


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
View user's profile Send private message
wschertz(at)ispwest.com
Guest





PostPosted: Sun Mar 12, 2006 6:21 am    Post subject: Starter problem analysis Reply with quote

Something else to check -- When the engine is hot, is it harder to turn over
by hand at the prop? The reason I ask is that a local builder had this
behavior, and it turned out that there was an internal engine problem that
made the engine bind when hot. Just something to check.
Bill Schertz
KIS Cruiser # 4045
---


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
brian



Joined: 02 Jan 2006
Posts: 643
Location: Sacramento, California, USA

PostPosted: Sun Mar 12, 2006 9:05 am    Post subject: Starter problem analysis Reply with quote

William wrote:
Quote:


Something else to check -- When the engine is hot, is it harder to turn over
by hand at the prop? The reason I ask is that a local builder had this
behavior, and it turned out that there was an internal engine problem that
made the engine bind when hot. Just something to check.

That is actually fairly normal. The cylinder walls cool and contract
more rapidly than do the pistons. This reduces clearances and increases
friction. It is worst about 10 minutes after shutdown or just about how
long it takes to put fuel in the airplane at the self-serve pumps.

Regardless, the starter should be able to rotate the engine at full
speed even with this additional load, especially given the voltage
numbers you are seeing. Your battery voltage is not sagging considerably
under this load nor do your voltage drops appear unreasonable between
battery and starter.

What you did not mention is the voltage drop on the ground side of
things. Place your voltmeter's positive lead on the starter case and
negative on the negative pole of the battery and crank. You may be
surprised at how much ground resistance you have. Check and fix that
first before getting a new starter.

OTOH, if you do all of this and find minimal losses, you are probably
going to have to face the need for a new or rebuilt starter.

--
Brian Lloyd 361 Catterline Way
brian-yak at lloyd dot com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)

I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

_________________
Brian Lloyd
brian-yak at lloyd dot com
+1.916.367.2131 (voice) +1.270.912.0788 (fax)

I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery
Back to top
View user's profile Send private message AIM Address
jm(at)10squaredcorp.com
Guest





PostPosted: Sun Mar 12, 2006 1:40 pm    Post subject: Starter problem analysis Reply with quote

Today I took it out for a trip around the pattern and checked it hot.
The battery voltage across the terminals while cranking was now
9.4-9.8 VDC versus about 1 VDC yesterday cold. I can turn the prop by
hand, so I don't think heat related binding of the engine is at
fault. I recharged the battery to provide the same starting point as
yesterday and checked the cranking voltage again and it's still below
10 VDC. I can measure 1 ohm resistance in the ground between the neg.
battery terminal and the engine ground strap. Starter casing was 130F
after shutdown.

Thanks for the input so far. I've been scratching my head trying to
think of a heat-related cause and trying to apply a systematic
approach to troubleshooting this problem so the correct part can be
replaced.

Jim

On Sunday 12 March 2006 17:03, Brian Lloyd wrote:
Quote:

<brian-yak(at)lloyd.com>

William wrote:
>
> <wschertz(at)ispwest.com>
>
> Something else to check -- When the engine is hot, is it harder
> to turn over by hand at the prop? The reason I ask is that a
> local builder had this behavior, and it turned out that there was
> an internal engine problem that made the engine bind when hot.
> Just something to check.

That is actually fairly normal. The cylinder walls cool and
contract more rapidly than do the pistons. This reduces clearances
and increases friction. It is worst about 10 minutes after shutdown
or just about how long it takes to put fuel in the airplane at the
self-serve pumps.

Regardless, the starter should be able to rotate the engine at full
speed even with this additional load, especially given the voltage
numbers you are seeing. Your battery voltage is not sagging
considerably under this load nor do your voltage drops appear
unreasonable between battery and starter.

What you did not mention is the voltage drop on the ground side of
things. Place your voltmeter's positive lead on the starter case
and negative on the negative pole of the battery and crank. You may
be surprised at how much ground resistance you have. Check and fix
that first before getting a new starter.

OTOH, if you do all of this and find minimal losses, you are
probably going to have to face the need for a new or rebuilt
starter.


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
Terry Watson



Joined: 09 Jan 2006
Posts: 290
Location: Seattle, WA USA

PostPosted: Sun Mar 12, 2006 2:13 pm    Post subject: Starter problem analysis Reply with quote

Yesterday the guys on Car Talk, a National Public Radio program about cars,
discussed a similar problem with an aging Volvo, if I remember correctly.
The car would start fine cold but would hardly turn over hot. The verdict
was that the starter was wearing out and its resistance increased as it got
hotter. They said he could put ice on the starter to cool it off, or get a
new starter.

All for what it's worth, of course.

Terry

--


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
View user's profile Send private message Send e-mail
Bob McC



Joined: 09 Jan 2006
Posts: 258
Location: Toronto, ON

PostPosted: Sun Mar 12, 2006 2:52 pm    Post subject: Starter problem analysis Reply with quote

Jim;

The resistance from the battery terminal to the engine ground strap doesn't
tell a lot. What would help, is to measure the voltage drop between the
battery negative post and the casing of the starter itself while cranking.
(not the crankcase or ground strap, but the starter casing) All your
measurements so far sound fine but I haven't seen you measure the ground
path voltage drop yet, which the measurement described above will give you.
This shouldn't be heat related but you never know how expansion of something
may be affecting the tightness of something in the loop. The other telling
number is the voltage between the positive battery post and the main
terminal at the starter while cranking. (again not the cable or lug
connected to the starter but the starter post itself.) These two readings
may give a clue where to look for a fix. The other thing missing from your
readings to date are all the same readings cold. You can then compare hot
and cold readings and see if any one changes dramatically. You might be on
to something however if I interpret correctly what you say below, that where
you previously had < 1 Volt drop you now have ~9.5. This would indicate a
bad connection somewhere between the two points where that voltage was
measured. By the way your measurement points at the battery should be
specifically the post, not the lug or cable connected to it, in case that
connection is part of the problem.

Bob McC
---


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

_________________
Bob McC
Falco #908
(just starting)
Back to top
View user's profile Send private message Send e-mail
brian



Joined: 02 Jan 2006
Posts: 643
Location: Sacramento, California, USA

PostPosted: Sun Mar 12, 2006 3:22 pm    Post subject: Starter problem analysis Reply with quote

Jim Michael wrote:

Quote:
fault. I recharged the battery to provide the same starting point as
yesterday and checked the cranking voltage again and it's still below
10 VDC.

That is not bad. 10V is fine for a cranking load. It doesn't sound like
your battery is bad at all. Is this 10V at the starter or at the battery?

Quote:
I can measure 1 ohm resistance in the ground between the neg.
battery terminal and the engine ground strap. Starter casing was 130F
after shutdown.

You probably do not have a meter that will measure the ground
resistance. A one ohm resistance in the ground would show up as
virtually no voltage at the starter. It wouldn't even try to crank. In
fact, almost nothing would work right with 1 ohm of resistance between
the engine case and negative terminal of the battery.

The only way you are going to be able to measure the ground resistance
is to measure the voltage drop and know the current or use something
like Bob's micro-ohmmeter attachment to your DVM.

Quote:
Thanks for the input so far. I've been scratching my head trying to
think of a heat-related cause and trying to apply a systematic
approach to troubleshooting this problem so the correct part can be
replaced.

I had the same problem in my Comanche not too long ago. It was the
battery. OTOH your battery seems not to have excessive voltage sag under
cranking load.

So please go back and measure your ground loss and/or verify voltage at
the starter (starter solenoid terminal to starter case). If you have 9V
there when the engine is cranking and the starter can barely turn over
the engine, either the engine is so bound up as to be impossible to turn
or your starter is bad.

--
Brian Lloyd 361 Catterline Way
brian-yak at lloyd dot com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)

I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

_________________
Brian Lloyd
brian-yak at lloyd dot com
+1.916.367.2131 (voice) +1.270.912.0788 (fax)

I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery
Back to top
View user's profile Send private message AIM Address
jm(at)10squaredcorp.com
Guest





PostPosted: Sun Mar 12, 2006 3:33 pm    Post subject: Starter problem analysis Reply with quote

Typo on the battery voltage: 9.4-9.8 hot and 10.4 cold at the
terminals during cranking. I'll get those other voltage measurements
next time I'm at the airport. Thanks again for the suggestions.

Jim

On Sunday 12 March 2006 22:49, Bob McCallum wrote:
[quote]
<robert.mccallum2(at)sympatico.ca>

Jim;

The resistance from the battery terminal to the engine ground strap
doesn't tell a lot. What would help, is to measure the voltage drop
between the battery negative post and the casing of the starter
itself while cranking. (not the crankcase or ground strap, but the
starter casing) All your measurements so far sound fine but I
haven't seen you measure the ground path voltage drop yet, which
the measurement described above will give you. This shouldn't be
heat related but you never know how expansion of something may be
affecting the tightness of something in the loop. The other telling
number is the voltage between the positive battery post and the
main terminal at the starter while cranking. (again not the cable
or lug connected to the starter but the starter post itself.) These
two readings may give a clue where to look for a fix. The other
thing missing from your readings to date are all the same readings
cold. You can then compare hot and cold readings and see if any one
changes dramatically. You might be on to something however if I
interpret correctly what you say below, that where you previously
had < 1 Volt drop you now have ~9.5. This would indicate a bad
connection somewhere between the two points where that voltage was
measured. By the way your measurement points at the battery should
be specifically the post, not the lug or cable connected to it, in
case that connection is part of the problem.

Bob McC
---


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
jm(at)10squaredcorp.com
Guest





PostPosted: Sun Mar 12, 2006 4:55 pm    Post subject: Starter problem analysis Reply with quote

On Sunday 12 March 2006 23:19, Brian Lloyd wrote:

Quote:
That is not bad. 10V is fine for a cranking load. It doesn't sound
like your battery is bad at all. Is this 10V at the starter or at
the battery?

I was gettting 10.4 at the battery and 9.8 at the starter cold. I got
9.8 at the battery hot.

Quote:
I had the same problem in my Comanche not too long ago. It was the
battery. OTOH your battery seems not to have excessive voltage sag
under cranking load.

So please go back and measure your ground loss and/or verify
voltage at the starter (starter solenoid terminal to starter case).
If you have 9V there when the engine is cranking and the starter
can barely turn over the engine, either the engine is so bound up
as to be impossible to turn or your starter is bad.

The fact that it was cranking cold seemed to rule out the bad ground,
but I'll take a look at that before having the starter replaced.

Jim


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
Display posts from previous:   
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> AeroElectric-List All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group