Create an account Home  ·  ·  Forums  ·  ·  Articles  ·  ·  Downloads  ·  ·  Photo Gallery  
Login
Nickname

Password

Don't have an account yet? You can create one here.

Navigation
· Home
· Article Archive
· Article Submit
· Downloads
· FAQ
· Forums
· Members List
· Photo Gallery
· Private Messages
· Web Links
· Your Account

Search Articles



Forums

Wiper motor...which is the correct one?
Lead additive, one more question.
M31C mount with or without replica weapon
Backfire and Hesitation
Wanted: Steering column and shaft for M38-1952, or late CJ2A
2024 CT. MILITARY VEHICLE SHOW AND FLEA MARKET- JUNE 15,2024
Brake Line
How to link full size photos in posts
Clutch release bearing support cast tab for return spring
T90 case replacement required?

Willys M Jeeps Forums


willysmjeeps.com :: View topic - M38A1 crank but not starting
 Forum FAQForum FAQ   SearchSearch   UsergroupsUsergroups   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

M38A1 crank but not starting
Goto page 1, 2, 3  Next
 
Post new topic   Reply to topic    willysmjeeps.com Forum Index -> Technical Knowledge Base
View previous topic :: View next topic  
Author Message
giacomo
Member


Joined: Apr 11, 2011
Posts: 68
Location: Italy

PostPosted: Sat Jun 25, 2022 2:37 am    Post subject: M38A1 crank but not starting Reply with quote

Hi all,
here I am with another problem
after two years in which the 1954 M38A1 has stood still, now it no starting
crank but not starting.....
the gasoline reaches the carburetor, but by disconnecting the spark plug cables and bringing them closer to the engine block at the moment of starting there are no sparks .....
primary capacitor - ignition coil or breaker point capacitor ...?
thank you

Giacomo
Back to top
View user's profile Send private message
cobra5
Member


Joined: Mar 10, 2013
Posts: 103
Location: Stevensville, Montana

PostPosted: Sat Jun 25, 2022 6:28 am    Post subject: Reply with quote

If it ran before you parked it, use a piece of sandpaper and clean the contacts on the breaker points and than check again for spark.
_________________
1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
Back to top
View user's profile Send private message Send e-mail
giacomo
Member


Joined: Apr 11, 2011
Posts: 68
Location: Italy

PostPosted: Sat Jun 25, 2022 8:23 am    Post subject: Reply with quote

yes it worked regularly before, and I already cleaned the contacts on the breaker points....
thank you

Giacomo
Back to top
View user's profile Send private message
RonD2
Member


Joined: Oct 02, 2014
Posts: 1889
Location: South Carolina, Dorchester County

PostPosted: Sat Jun 25, 2022 8:53 am    Post subject: Reply with quote

Hi Giacomo,
You don't say if your M38A1 is original. Original carburetor? Never rebuilt? Original 24-volt electrical system?

It's hard enough to guess the problem from long distance sight unseen. Taking some photos and giving a description and history of your jeep would help.

Until then, I suggest begin by draining and flushing the old gasoline from everywhere (tank, lines, carb, pump). Buy some fresh fuel.

Then open the Army manual TM9-8014 that you downloaded for free and follow the steps in Section IV Troubleshooting that begin on page 79.

Good luck!
_________________
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51

“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari

Back to top
View user's profile Send private message Send e-mail
giacomo
Member


Joined: Apr 11, 2011
Posts: 68
Location: Italy

PostPosted: Sat Jun 25, 2022 11:13 am    Post subject: Reply with quote

Hi RonD2
M38A1 original with original carburetor rebuilt 3 years ago and original 24V electrical system
unloaded the old gasoline from the tank and filled with fresh fuel
thank you


Giacomo
Back to top
View user's profile Send private message
cobra5
Member


Joined: Mar 10, 2013
Posts: 103
Location: Stevensville, Montana

PostPosted: Sat Jun 25, 2022 2:21 pm    Post subject: Reply with quote

The other thing that will prevent you from getting spark is the ignition switch
_________________
1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
Back to top
View user's profile Send private message Send e-mail
giacomo
Member


Joined: Apr 11, 2011
Posts: 68
Location: Italy

PostPosted: Sat Jun 25, 2022 2:48 pm    Post subject: Reply with quote

I also did this test, I disconnected the electrical cable from the wiring harness receptacle and with ignition switch on and measured the voltage: 24V......
thank you

Giacomo
Back to top
View user's profile Send private message
cobra5
Member


Joined: Mar 10, 2013
Posts: 103
Location: Stevensville, Montana

PostPosted: Sat Jun 25, 2022 3:16 pm    Post subject: Reply with quote

Is the distributor rotor spinning when the engine is cranking? All connections clean and tight inside the distributor? Have you performed the ohms check on the coil yet?
_________________
1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
Back to top
View user's profile Send private message Send e-mail
BBDE
Member


Joined: Mar 05, 2008
Posts: 77
Location: Berlin Germany

PostPosted: Sun Jun 26, 2022 12:30 pm    Post subject: Reply with quote

If you don't have an ignition spark although there is 24 volts at the distributor and you have already cleaned the contacts, the distributor shaft rotates when you turn the engine, you have also already checked the distributor cap, fingers, cables and spark plugs, it may be the ignition coil is shot.
If the ignition has been switched on for a long time and the engine has not been running, the ignition coil may have been damaged.

The old originals are more short-circuit proof than, for example, the repro coils, but they also have their load limits.

In any case, you should proceed logically and systematically when troubleshooting and not try a little here and there.

a look at the manuals will definitely help you.
You will surely get the needed help and the necessary tips here in the forum.

Frank

Good luck
Back to top
View user's profile Send private message
giacomo
Member


Joined: Apr 11, 2011
Posts: 68
Location: Italy

PostPosted: Thu Dec 08, 2022 7:19 am    Post subject: Reply with quote

Hi all,
the problem comes back : hard starting to cold engine
Could it be a bad coil ?
how is it measured ?
also how can I measure the speed of the starter to exclude it as the cause of a slow cranking speed ?
thank you

Giacomo
Back to top
View user's profile Send private message
RonD2
Member


Joined: Oct 02, 2014
Posts: 1889
Location: South Carolina, Dorchester County

PostPosted: Thu Dec 08, 2022 9:33 am    Post subject: Reply with quote

Hi Giacomo,
Did you check to see if you have bright blue spark across a spark plug gap when cranking the engine?
If yes, the coil isn't the problem.

Are your batteries fully charged?
You might test them (at battery shop) for full cranking amp capacity.

I believe some smart phones can measure RPM of a cranking engine.
Or you can buy a portable tachometer.
I believe the starter should crank the engine about 200 RPM.

You never told us --- what did you do to fix your last problem back in June?

Good luck!
_________________
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51

“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari

Back to top
View user's profile Send private message Send e-mail
giacomo
Member


Joined: Apr 11, 2011
Posts: 68
Location: Italy

PostPosted: Thu Dec 08, 2022 12:08 pm    Post subject: Reply with quote

Hi Ron,
I still have to check bright blue spark across from the cable to the engine block ( new spark plugs ) but in any case how do you check the coil with the tester ?

batteries fully charged

I've actually never fixed it....

thank you
Giacomo
Back to top
View user's profile Send private message
RonD2
Member


Joined: Oct 02, 2014
Posts: 1889
Location: South Carolina, Dorchester County

PostPosted: Thu Dec 08, 2022 12:50 pm    Post subject: Reply with quote

Giacomo,
If you search "coil test" using the search button above you'll get lots of information, including this one: http://willysmjeeps.com/v2/modules.php?name=Forums&file=viewtopic&t=13461&highlight=coil+test

Good luck!
_________________
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51

“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari

Back to top
View user's profile Send private message Send e-mail
wesk
Site Administrator
Site Administrator


Joined: Apr 04, 2005
Posts: 16225
Location: Wisconsin

PostPosted: Thu Dec 08, 2022 9:33 pm    Post subject: Reply with quote

You may also want to review this post as well: http://www.willysmjeeps.com/v2/modules.php?name=Forums&file=viewtopic&t=5652

Don't forget to do the test at room temp and then again after heating the coil up with a hair dryer or heat gun.

Also try to remember the Ohm meter checkout can be used with some reliability but the preferred method is with an actual coil tester that measures coil current draw.



Also in my photo album Titled: Ignition Systems L & F 134 engines. http://www.willysmjeeps.com/v2/modules.php?set_albumName=album119&op=modload&name=gallery&file=index&include=view_album.php, in sub-album titled Distributor: http://www.willysmjeeps.com/v2/modules.php?set_albumName=album121&op=modload&name=gallery&file=index&include=view_album.php
You will also find a complete PrestoLite/Autolite test sheet set:





There are several pages of advance curves just download the one that applies to your specific part number distributor.
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php
Back to top
View user's profile Send private message Send e-mail Visit poster's website
giacomo
Member


Joined: Apr 11, 2011
Posts: 68
Location: Italy

PostPosted: Fri Dec 09, 2022 10:46 am    Post subject: Reply with quote

Today I checked the coil with VOM digital test and the following results:
primary : 6,9 ohms
secondary ( between B and D ) :open ( no reading )
then i tested a second coil and the result is the same
could this be the cause of the increasingly difficult starts ?
and where can I buy a coil that is valid ... ?
thank you

Giacomo
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    willysmjeeps.com Forum Index -> Technical Knowledge Base All times are GMT - 6 Hours
Goto page 1, 2, 3  Next
Page 1 of 3

 
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

Powered by phpBB © 2001 phpBB Group
Forums ©

 



PHP-Nuke Copyright © 2005 by Francisco Burzi. This is free software, and you may redistribute it under the GPL. PHP-Nuke comes with absolutely no warranty, for details, see the license.