M38A1 eating coils and Condersers

Silvercrown · Post by **Silvercrown** » Sun Apr 05, 2015 8:02 am

Hi guys, I’m helping a friend on his A1 that is having problems that mine has never given me. His jeep is eating coils and condensers. We replaced the coil and it it got him through last summer. I though we were good to go. Couple weeks ago it ate the next coil and I new we had a problem. We replaced that one with a good US made coil and I started looking at over heating issues and cleaned out all the vent ect. Then the jeep just one day would bairly start and run, running very rough then finally just stopped. I figured it was the condenser and put a nos one on and it was fine. Few days later we are back to the same thing. It appears to have killed the nos condenser. I’m thinking voltage regulator is set to hot but wanted to run it past the group here for guidance before we opened up the regulator for adjustment. Is killing the condenser a symptom of something else? Thanks guys

Mike

Post by **wesk** » Sun Apr 05, 2015 8:20 am

The most common causes for an autopsy on coils & condensers:

1-Cheap off shore replacements
2-Heat. The vent plumbing is there for two reasons: remove ionized gases and cool the coil.
3-Overvoltage. This is usually the regulator setting is to high.
4-Leaving the ignition on when the engine isn't running and the points are closed. High current draw and heat. This is easy to prevent but also very easy to do. Add an idiot light in plain sight on the dash that stays on until the ignition switch is turned off.
5-The insulator on the points not positioned properly allowing points to short to ground or the negative wire from the coil to the points is shorting to ground.

skyjeep50 · Post by **skyjeep50** » Sun Apr 05, 2015 10:23 am

I raise the hood on my jeeps after shutdown to get some airflow through the engine compartment. If I'm stopping anywhere but home I have a small block of wood (painted OD) so I can raise the hood at least couple of inches, at home the hood is opened all the way. If the jeep is running down the road airflow through the vent and engine bay keeps things relatively cool but the highest temps occur right after engine shutdown as the engine and components bake in their own heat. I don't know if this will help preserve a coil a lot or a little but it costs nothing and is easy to do.

oreo3156 · Post by **oreo3156** » Sun Apr 05, 2015 10:36 am

stock 24volt system or converted to 12volt?

Some 12 volt coils require an external resistor.

Silvercrown · Post by **Silvercrown** » Sun Apr 05, 2015 3:44 pm

His jeep is stock 24V.

Mikeabn · Post by **Mikeabn** » Sat Apr 11, 2015 12:23 pm

I notice in TM9-8015-5 page 151 it specifically calls for distributor vent line to be restricted to 0,040 inch. It this is used to insure gases and cool the coil, does it hurt if this hole is larger? A standard bushing has a larger hole. I notice it speaks about control vacuum within the distributor. Currently, both vent holes in my distributor are plugged. My next step is to install the proper vent lines, but wondered if a larger hole for more "vent" is better than the controlled vacuum within the distributor. I have 20# of vacuum at engine but it falls off somewhat at the vacuum portion of the fuel pump. Until I get the vent lines installed, should I remove one or both of the plugs in the distributor holes to insure coil or condenser don't overheat?
Thank you

Mike

Post by **wesk** » Sat Apr 11, 2015 2:27 pm

2-Heat. The vent plumbing is there for two reasons: remove ionized gases and cool the coil.

The restrictor is there to control the amount of Vacuum airflow being returned to the intake. In other words it is a calibrated vacuum leak and making it greater will cause the engine to run leaner than it should.

Plugging the air flow ports in the distributor in warm climates is not smart.