Another Coil Issue

[oldodge41]

Been working on my D19 off and on for awhile now. I started having issues early in the summer. After 20 minutes or so of driving, the car would start running rough, missing, stumbling on acceleration and surging at cruising speed. After sitting awhile everything ran ok, not as smooth as a flattie should but ok. I suspected vapor lock since I have had those issues before and this felt similar but it never quit. After swapping out the rear diff I was adjusting brakes, test driving and repeating. Seemed the longer I did this the worse it ran. I put it in the garage and adjusted the brakes again, when I tried to start it I had no spark. Checked points and could see no spark at points. Replaced with my spare set and it started right up but had a high rpm miss. Looking at the points fire it looked like way too much spark. I suspected condenser but didn't have a spare on hand so I quit for the day. A couple days later I started it right up and started up the road only to have no power, missing and bucking. I pulled the distributor because my spark at the points was now very faint and I wanted to have a good look. Everything looked good but it still ran like crap. Was reading some posts on here and it hit me like a ton of bricks! This all started with the car only missing after everything heated up and got progressively worse until what I have now! It's the dang COIL!!! Today, I threw in the one from my Dart, hung it from the one horn with ty-straps, and fired it up. Ran very smooth in the garage and a short ride told the tale. This thing hasn't run this good in a very long time. I've been thinking loss of power due to compression but have held off doing a compression check because I didn't really want to know. Now I fully believe it has been a deteriorating coil all along. Getting it running right I finally got to really try out the new rear and I am very pleased. My speedometer is really way off now, but I will address that later. Been working on cars for a lot of years and never had a coil do this before. Heard of coil failures, but never saw it in person before......................Tim

[JIPJOBXX]

If you want to test a coil that seems to be going out-just rap some ice around it and it will usually be ok for a while. Even after that 20 minutes if you can just get it cool down than it should work.

[Plymouthy Adams]

not saying you are not n the right area but never rule out the expansion of the valves and not seating when engine get hot...have yuou adjusted/checked the lash since taking ownership?

[oldodge41]

Yes, I have adjusted the valves many times. I have owned this car for about 20 years. The change in overall performance when I attached the new coil was unbelievable, but I ran it long enough to know that the coil was the issue. I understand the ice theory. I think this one was really breaking down quickly at the end. Not sure if iceing it would have helped at that point or not. Thanks for the input..................Tim

[Jim Yergin]

Was reading some posts on here and it hit me like a ton of bricks! This all started with the car only missing after everything heated up and got progressively worse until what I have now! It's the dang COIL!!! Tim

Tim,

I just recently had the same "A-HA" moment too with my '41 Plymouth. So far, since replacing the coil, no more problems.

Jim Yergin

[oldodge41]

Jim,

I think your post may have been the one I was reading that led me to my conclusions. That is why I posted my story. Maybe it can help someone sometime...............Tim