Engine starts when cold, won't crank when warm

[mr.green]

Haven’t posted in a while, but I have one that has me stumped, and could use some advice..
My engine starts when cold. When the engine is warm and I turn the engine off and then try to restart it, it acts like the battery is nearly dead. I’ve had the batteries checked at two locations and both say the batteries are good. Once the engine is completely cold, the coach starts just fine.
I recently had both the alternator and starter replaced thinking they were part of the problem (they need replacing anyway) but that did not solve the problem.
After stopping with the engine not running I get a 12 volt reading from the battery, and while the engine is running I get a14.5 reading at the battery, so it appears that the batteries are charging while the engine is running
Coach runs fine until I stop, then it barely cranks over, until it is cold again several hours later.
thanking everyone in advance for your thoughts.

David Gardner
1976 Birchaven (455 motor)
Oxnard Ca

 

[wayne rogewski]

Does engaging the boost switch do anything or make any difference with the hard crank condition?

Possibly a bad cable or ground. Sounds like everything else was replaced already.
--
77 Royale, Rear Dry Bath. 403, 3.55 Final Drive, Lenzi goodies, Patterson carb and dizzy.
Mid Michigan

 

[Jim Hupy]

Simple answer, battery cables and grounds. Feel the cables with your bare
hands. Any hot ones, investigate further.
Jim Hupy
Salem, Or
78 GMC ROYALE 403

> Does engaging the boost switch do anything or make any difference with the
> hard crank condition?
>
> Possibly a bad cable or ground. Sounds like everything else was replaced
> already.
> --
> 77 Royale, Rear Dry Bath. 403, 3.55 Final Drive, Lenzi goodies, Patterson
> carb and dizzy.
> Mid Michigan
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[scott nutter1]

I had the same problem.
I put on a new starter, and increased the gauge of wire to the starter. Both negative and positive.
That cured the problem. It seems to be a fairly common problem.
Scott
--
Scott Nutter
1978 455 Royale Center Kitchen, Quad bags.
Houston, Texas

 

[a.]

> Haven't posted in a while, but I have one that has me stumped, and could use some advice..
> My engine starts when cold. When the engine is warm and I turn the engine off and then try to restart it, it acts like the battery is nearly
> dead. I've had the batteries checked at two locations and both say the batteries are good. Once the engine is completely cold, the coach starts
> just fine.
> I recently had both the alternator and starter replaced thinking they were part of the problem (they need replacing anyway) but that did not solve
> the problem.
> After stopping with the engine not running I get a 12 volt reading from the battery, and while the engine is running I get a14.5 reading at the
> battery, so it appears that the batteries are charging while the engine is running
> Coach runs fine until I stop, then it barely cranks over, until it is cold again several hours later.
> thanking everyone in advance for your thoughts.
>
> David Gardner
> 1976 Birchaven (455 motor)
> Oxnard Ca
http://www.gmcmhphotos.com/photos/gmc-cranking-improve-for-free/p34367-hot-start-problem-2c-battery-2f-starter.html
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"Highest price does not guarantee highest quality."

 

[bdub1]

Ya might try retarding the timing just a bit.

> Haven’t posted in a while, but I have one that has me stumped, and could
> use some advice..
> My engine starts when cold. When the engine is warm and I turn the engine
> off and then try to restart it, it acts like the battery is nearly dead.
> I’ve had the batteries checked at two locations and both say the batteries
> are good. Once the engine is completely cold, the coach starts just fine.
> I recently had both the alternator and starter replaced thinking they were
> part of the problem (they need replacing anyway) but that did not solve the
> problem.
> After stopping with the engine not running I get a 12 volt reading from
> the battery, and while the engine is running I get a14.5 reading at the
> battery, so it appears that the batteries are charging while the engine is
> running
> Coach runs fine until I stop, then it barely cranks over, until it is cold
> again several hours later.
> thanking everyone in advance for your thoughts.
>

 

[bdub1]

Before ya turn the distributor, make sure that the mechanical advance
flyweights aren't frozen in the extended position.

> Ya might try retarding the timing just a bit.
>

>
>> Haven’t posted in a while, but I have one that has me stumped, and could
>> use some advice..
>> My engine starts when cold. When the engine is warm and I turn the
>> engine off and then try to restart it, it acts like the battery is nearly
>> dead. I’ve had the batteries checked at two locations and both say the
>> batteries are good. Once the engine is completely cold, the coach starts
>> just fine.
>>
>

 

[rod utterback]

Replace the battery. Your measurements tells it all. A good battery should read about 13.2 volts. The fact that you read 12 after the engine is shut off is key. The 14.5 volts while engine is running indicates the charging system is fine. Poor cables or bad connections may be an issue as a warm start may over heat battery connections. Then consider the ignition timing. If it is advanced (correctly or incorrectly set) a warm engine may actually be harder to start than when cold. My experience says replace the battery. Question: will it start in boost position? If so then you must have a bad battery or possibly an undersized one or bad cable/connection somewhere.

Good luck

Rod cruzin in South Cali

From: Billy Massey

 

[Matt Colie]

I will start by saying that this is exactly the symptoms my coach had before I discovered that the started was toast about 10K miles back. (He got it
down, cracked the back plate off and said,"Oh God - That's not fixing here!")

Now -
While we are at it, a good battery at rest should read 12.6 with some load. Maybe 12.7 with zero load. If you don't see that, first go to a car
parts store and check your meter on a new battery on the shelf. Then, get an new battery. but the hot/cold is so reminiscent of my starter failure,
that I think that you should look there when you don't find some other answer. A starter is the only heavy spare part I carry. There is a reason.

A 10MT starter is so robust that it was used from 1956 to the late 90s. The problem is that it is Too Robust. It will keep trying when it should
have quit and gone home long before. Then the is the problem that the 10MT for the TH425 went out of production 38 years ago. You can get a rebuilt,
but don't expect it to be in anybody X-stock list. If you haven't looked into your starter recently, think about it. Changing brushes is cheap and
easy.

Matt

--
Matt & Mary Colie - Members GMCMI, GMCGL, GMCES
'73 Glacier 23 - Still Loving OE Rear Drum Brake with Applied Control Arms
Now with both true Keyless and remote entry
SE Michigan - Twixt A2 and Detroit

 

[kab7]

Any suggestions on a good rebuild kit (or what should be in such a kit)?
Seems like cheap insurance and lighter/cheaper than carrying around a whole spare starter.
Might not always be able to fix it, but a rebuild kit could keep you from being stranded
(or you could just do a pre-emptive rebuild with it).

thanks,
Karen
1975 26'

> A 10MT starter is so robust that it was used from 1956 to the late 90s. The problem is that it is Too Robust. It will keep trying when it should
> have quit and gone home long before. Then the is the problem that the 10MT for the TH425 went out of production 38 years ago. You can get a
> rebuilt, but don't expect it to be in anybody X-stock list. If you haven't looked into your starter recently, think about it. Changing brushes is
> cheap and easy.

 

[Jim Hupy]

Most of the starter failures can be traced to the solenoid contactor disc.
It no longer is solid copper, but a cheap substitute that has a thin copper
foil like coating that will not handle the amperage loads of the starter.
It arcs off a bit of the foil coating with each use. It is staked on to the
solenoid plunger and is difficult to remove and reverse like the solid disc
can. So, definitely, the solenoid should be included in your spare parts.
Thrust washers, and brushes, as well as the bushing in the nose casting.
Jim Hupy
Salem, Or
78 GMC ROYALE 403

> Any suggestions on a good rebuild kit (or what should be in such a kit)?
> Seems like cheap insurance and lighter/cheaper than carrying around a
> whole spare starter.
> Might not always be able to fix it, but a rebuild kit could keep you from
> being stranded
> (or you could just do a pre-emptive rebuild with it).
>
> thanks,
> Karen
> 1975 26'
>
>

> > A 10MT starter is so robust that it was used from 1956 to the late 90s.
> The problem is that it is Too Robust. It will keep trying when it should
> > have quit and gone home long before. Then the is the problem that the
> 10MT for the TH425 went out of production 38 years ago. You can get a
> > rebuilt, but don't expect it to be in anybody X-stock list. If you
> haven't looked into your starter recently, think about it. Changing
> brushes is
> > cheap and easy.
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[Ken H.]

When we removed Lou Boone's transmission two weeks ago for Manny to rebuild
it here, we broke the starter. Cracked the bakelite housing which supports
the primary 12VDC connection. Rather than fool with tearing down one of
the old starters laying around here for a replacement housing, we took it
to the local Carb/Ignition shop. Charlie Smith, the owner, is about 65.
He started work at 17 for one of my grandfather's best friends. He now
owns the shop, piled high with old carbs, starters, generators and
alternators. He won't touch a fuel injected car, 'tho' he does do diesel
mechanical fuel injection.

We took Lou's starter to him on Thursday afternoon: "Charlie, is there any
way you can possibly get this fixed by quitting time tomorrow so we can
install it over the weekend?" "Aw man, I'm so busy, NO WAY! ... OK, have
my wife check it in and I'll see what I can do -- but don't count on it."

On the way home from lunch, we stopped at Charlie's to pick up the starter,
fixed or not. What we found was a shiny new-looking one. "It was in
pretty good shape, brushes looked real good. But one armature bushing was
worn so I replaced it. Found a near-new switch housing on an old starter.
It should work OK now..." Total bill? $22.00. Good Ol' Charlie!

Ken H.

> > A 10MT starter is so robust that it was used from 1956 to the late 90s.
> The problem is that it is Too Robust. It will keep trying when it should
> > have quit and gone home long before. Then the is the problem that the
> 10MT for the TH425 went out of production 38 years ago. You can get a
> > rebuilt, but don't expect it to be in anybody X-stock list. If you
> haven't looked into your starter recently, think about it. Changing
> brushes is
> > cheap and easy.
>

 

[Matt Colie]

> Any suggestions on a good rebuild kit (or what should be in such a kit)?
> Seems like cheap insurance and lighter/cheaper than carrying around a whole spare starter.
> Might not always be able to fix it, but a rebuild kit could keep you from being stranded (or you could just do a pre-emptive rebuild with it).
>
> thanks,
> Karen
> 1975 26'

Karen,

The pre-emptive rebuild is really the good idea.
If you had a set of brushes and screws for same, you could probably bring a dead starter back to life.
But,
Of the two that I have seen that failed in service, they really needed the commutator trued (takes a lathe) and the front bushing changed out.
(One of those was mine and it was Sunday afternoon in BF Egypt.)

If you were wondering, the life seems to be about that of a 455 *1.25. So the simple answer would be, if you have the engine out, rebuild the starter
while all you have to do is pick it off the floor. If you are doing anything that requires getting the starter down, three little fasteners and the
back plate gets open. Look inside and see how much brush is left. If the brush arm is within 1/16 of the commutator, think about getting that taken
care of before it goes back in.

My starter that I have is fresh. I carry the known good used starter just in case some friend needs it.

Matt
--
Matt & Mary Colie - Members GMCMI, GMCGL, GMCES
'73 Glacier 23 - Still Loving OE Rear Drum Brake with Applied Control Arms
Now with both true Keyless and remote entry
SE Michigan - Twixt A2 and Detroit

 

[Matt Colie]

> When we removed Lou Boone's transmission two weeks ago for Manny to rebuild
> it here, we broke the starter. Cracked the bakelite housing which supports the primary 12VDC connection. Rather than fool with tearing down one
> of
> the old starters laying around here for a replacement housing, we took it to the local Carb/Ignition shop. Charlie Smith, the owner, is about
> 65.
> He started work at 17 for one of my grandfather's best friends.
>
> On the way home from lunch, we stopped at Charlie's to pick up the starter, fixed or not. What we found was a shiny new-looking one. "It was in
> pretty good shape, brushes looked real good. But one armature bushing was worn so I replaced it. Found a near-new switch housing on an old
> starter.
> It should work OK now..." Total bill? $22.00. Good Ol' Charlie!
>
> Ken H.

Ken,

I think you know how lucky you are to have Charlie around.
I just lost my best local shop to a strip mall and the second choice shop is getting kind of shabby looking and he can't even keep a kid to do the
grunt work. I give him one - maybe two years more.

Matt
--
Matt & Mary Colie - Members GMCMI, GMCGL, GMCES
'73 Glacier 23 - Still Loving OE Rear Drum Brake with Applied Control Arms
Now with both true Keyless and remote entry
SE Michigan - Twixt A2 and Detroit

 

[johnny]

Dollar Carburetor and Electric in Gainesville, GA. "Here's the brush kit and nose bushing, I'll have the module after 7 tomorrow morning. 19 bux for
the parts. Works like a new one.

--johnny
--
'76 23' transmode Norris upfit, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.

"Sometimes I wonder what tomorrow's gonna bring when I think about my dirty life and times" --Warren Zevon

 

[Gene Fisher]

Read here
http://www.gmcmhphotos.com/photos/g5493-gmc-cranking-improve-for-free.html

> Haven’t posted in a while, but I have one that has me stumped, and could
> use some advice..
> My engine starts when cold. When the engine is warm and I turn the engine
> off and then try to restart it, it acts like the battery is nearly dead.
> I’ve had the batteries checked at two locations and both say the batteries
> are good. Once the engine is completely cold, the coach starts just fine.
> I recently had both the alternator and starter replaced thinking they were
> part of the problem (they need replacing anyway) but that did not solve the
> problem.
> After stopping with the engine not running I get a 12 volt reading from
> the battery, and while the engine is running I get a14.5 reading at the
> battery, so it appears that the batteries are charging while the engine is
> running
> Coach runs fine until I stop, then it barely cranks over, until it is cold
> again several hours later.
> thanking everyone in advance for your thoughts.
>
> David Gardner
> 1976 Birchaven (455 motor)
> Oxnard Ca
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://bdub.net/gmcmotorhome.info/
Alternator Protection Cable
http://bdub.net/gmcmotorhome.info/APC.html

 

[LQQKatJon]

lots of good suggestions here.

what you describe, just sounds so much like battery cable/battery problems. Or even the starter. my experience, is my GMC cranks over pretty well
at any temp. I have a rebuilt starter from a old time auto electric rebuild shop. good battery, and I have replaced the cables with some heavy awg
cables, with the hot lead from the starter going directly to the starter. However I also did this 5 years ago now, and I learned last trip, I had
corrosion that caused an issue on the house bank. So even if you think it is good, check, clean those connections. No reason your engine should
not spin over well. when I had my starter rebuilt, it was cranking, but when I got it back, it was spinning double the speed.

I have seen plenty of battery tests done and passed, and the batteries were still garbage. Especially when it comes to temperatures.

You can bypass your isolator to take that out of the system, to make sure you do not have some other goofy short robbing power from the starter.


--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/

 

[j artz]

I worked at VW dealerships for years, and a common problem on older automatic trans Rabbits, Golfs and Jettas was a hot soak problem in the ignition
switch feed wire to the starter. Would start fine cold, but once it was nice and hot, nothing. The automatic cars have the starter on the back of the
engine, under the exhaust manifold so plenty of heat there. Sticks never had the problem, the starter is on the front side.

The fix was to put a relay under the hood, using the original ignition switch feed wire to activate it. Run a new wire from the relay to the starter,
and feed the relay directly from the battery.

A quick and easy way to check for this is with a remote starter switch. One clip to the battery cable at the starter, the other to the ignition switch
start terminal. That bypasses the whole ignition switch circuit.
--
John in Omaha
74 26' Sequoia

 

[jim kanomata1]

J Artz,
It's great to get feedback and new ideas from people that have been on the
line.
Should you get a chance to show us how we might be able to make the
modification, it will be very helpful to the community.
Since 1980 I have seen lot of great information applied to the community
from people that have been on the front line and know their "SHEET" get us
helpful information and ideas.
I know there are lot of you out there, and I encourage them to help us.

> I worked at VW dealerships for years, and a common problem on older
> automatic trans Rabbits, Golfs and Jettas was a hot soak problem in the
> ignition
> switch feed wire to the starter. Would start fine cold, but once it was
> nice and hot, nothing. The automatic cars have the starter on the back of
> the
> engine, under the exhaust manifold so plenty of heat there. Sticks never
> had the problem, the starter is on the front side.
>
> The fix was to put a relay under the hood, using the original ignition
> switch feed wire to activate it. Run a new wire from the relay to the
> starter,
> and feed the relay directly from the battery.
>
> A quick and easy way to check for this is with a remote starter switch.
> One clip to the battery cable at the starter, the other to the ignition
> switch
> start terminal. That bypasses the whole ignition switch circuit.
> --
> John in Omaha
> 74 26' Sequoia
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk
http://www.appliedgmc.com
1-800-752-7502

 

[j artz]

It's a pretty simple wiring modification, you want the existing wire from the ignion switch to trigger the relay instead of the starter solenoid. The
starter circuit from the ignition switch runs all over, some of it in very hot areas. This shortens the current path immensely. Here's a simple
diagram I found online. The terminal numbers are all German style wiring codes, but the diagram gets the point across :

http://s1081.photobucket.com/user/rootesrefuge/media/Mobile%20Uploads/BoschWR1Diagram_zpsisvpqq0g.jpg.html

Essentially functions the same way a remote starter switch works. Or for that matter, like the old screwdriver across the starter terminals trick. A
weatherproof relay like a fog light relay, or even a Ford style remote solenoid would work fine.

--
John in Omaha
74 26' Sequoia