Engine problem
- Ronnie
- Member
- Posts: 4
- Joined: Sun May 25, 2008 6:00 pm
Engine problem
How will you know if distributor condenser is failing?When I increase the rpm of my jeep it is somewhat it will going to die and it is spluttering.Is it my condenser is malfunctioning?I am Ronnie Makalintal here in Philippines and need help thank you.
- capescw
- Active Member

- Posts: 150
- Joined: Sun May 13, 2012 6:00 pm
- Location: Milford CT
- Contact:
One possibility
When that happened to me, I discovered the weakened spring on the points was causing the points to 'float' at higher RPM. Easily checked with a spring-type gauge, but just moving it with your finger will possibly tell you. A defective capacitor will cause the points to burn or mis-shape (metal transferred from one contact to the other).
"Frugality keeps me in the Game"
1952 M38 Project "Lazarus"
1951(?) M100 Trailer
1956-60 USAF Special Weapons Program
http://www.bill-capes.com/insanity - Updated 04/26/14
1952 M38 Project "Lazarus"
1951(?) M100 Trailer
1956-60 USAF Special Weapons Program
http://www.bill-capes.com/insanity - Updated 04/26/14
- wesk
- Site Administrator

- Posts: 16467
- Joined: Sun Apr 03, 2005 6:00 pm
- Location: Wisconsin
- Contact:
Ronnie,
A capacitor and condenser are essentially the same thing. The auto industry labeled the capacitor in ignition systems a condenser over 3/4 ths of a century ago. So please don't let the use of both terms confuse you.
To make matters worse in a M38 24 volt distributor both terms are used. The capacitor used to absorb high voltages as the ignition contacts start to open are called condensers and the capacitor in the small threaded nipple where wire #12 connects is a radio noise filter and is still called a capacitor.
If the contact points are clean, not burned or pitted and not having any rough deposits on one side or the other then in all liklyhood your condenser is fine.
There are several issues that will cause your symptoms.
1 - Loose contacts. Set gap and tightened the two screws.
2 - Contacts improperly adjusted. Re-adjust.
3 - Weak coil. Substitute known good coil. Or test per the illustration below.

4 - Loose terminal connections and/or grounding at the insulator. See illustration below.

5 - Centrifugal advance mechanism inoperative due to damage or corrosion or interference. A quick check can be done by grasping the rotor and trying to rotate it left and right. It should move freely about 10 to 15 degrees. and spring back when released on it's own. See illustration below.

6 - Carb accelerator pump not working. Check for deteriorated vacuum diaphragm or improperly installed spring. See illustration below.

remove 4 screws "V" and diaphragm cover "W" then inspect diaphragm "Y" for tears or cracks or stiffness. Make sure spring is on the correct side of the diaphragm.
In the illustration below the capacitor used as a radio noise filter is item "QQ". In rare cases it can fail open causing no ignition or deteriorate and cause resistance to build up mimicking a weak coil. Unless you are operating complex sensitive radios you really do not need it and Mike Seymour posted a quick way to eliminate it and not have to change the wiring.


Original radio noise filter capacitor with lead.

Modified capacitor.

Mike used a drill to replace the original capacitor's pin. Any material that matches the pin's original dimensions and conducts electricity will work.

Modified capacitor re-installed in receptacle.
A capacitor and condenser are essentially the same thing. The auto industry labeled the capacitor in ignition systems a condenser over 3/4 ths of a century ago. So please don't let the use of both terms confuse you.
To make matters worse in a M38 24 volt distributor both terms are used. The capacitor used to absorb high voltages as the ignition contacts start to open are called condensers and the capacitor in the small threaded nipple where wire #12 connects is a radio noise filter and is still called a capacitor.
If the contact points are clean, not burned or pitted and not having any rough deposits on one side or the other then in all liklyhood your condenser is fine.
There are several issues that will cause your symptoms.
1 - Loose contacts. Set gap and tightened the two screws.
2 - Contacts improperly adjusted. Re-adjust.
3 - Weak coil. Substitute known good coil. Or test per the illustration below.

4 - Loose terminal connections and/or grounding at the insulator. See illustration below.

5 - Centrifugal advance mechanism inoperative due to damage or corrosion or interference. A quick check can be done by grasping the rotor and trying to rotate it left and right. It should move freely about 10 to 15 degrees. and spring back when released on it's own. See illustration below.

6 - Carb accelerator pump not working. Check for deteriorated vacuum diaphragm or improperly installed spring. See illustration below.

remove 4 screws "V" and diaphragm cover "W" then inspect diaphragm "Y" for tears or cracks or stiffness. Make sure spring is on the correct side of the diaphragm.
In the illustration below the capacitor used as a radio noise filter is item "QQ". In rare cases it can fail open causing no ignition or deteriorate and cause resistance to build up mimicking a weak coil. Unless you are operating complex sensitive radios you really do not need it and Mike Seymour posted a quick way to eliminate it and not have to change the wiring.


Original radio noise filter capacitor with lead.

Modified capacitor.

Mike used a drill to replace the original capacitor's pin. Any material that matches the pin's original dimensions and conducts electricity will work.

Modified capacitor re-installed in receptacle.
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. ... _album.php
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. ... _album.php
- cabinfever
- Active Member

- Posts: 201
- Joined: Mon May 13, 2013 6:00 pm
- Location: Between Crosslake and Emily, Minnesota
Wes, even though I don't need your advice on this issue....YET....thank you so much for all of your assistance, fine descriptions, and excellent photos. This forum is truly a gem and a wealth of kownledge, experience, and information. Thanks.
Steve Stark - 1955 M38A1 MD #85388
Member - MVPA #35153
Member - Red Bull Historic Military Vehicle Association
Member - MVPA #35153
Member - Red Bull Historic Military Vehicle Association

