Points Troubleshooting

[_shel_ny]

Question: when an engine is shut and is not running, will the points be open, closed, or not consistant either way?

 

Take a spare distributor with the points gap properly set.

 

Make 1 full revolution measuring the total degrees either open or closed.

 

Compare total open vs closed to determine the odds of open or closed when you shut off.

 

Or start your vehicle, and shut off. Remove cap. Check open, or closed. Document. Repeat 1000 times to get a realistic probability.

[Plymouthy Adams]

Shel..I will give you the odds on that...zero..PP is not going to go to any trouble to get statistics...he was not even concerned enough to look prior to asking the question..

[pflaming]

Not true Mr. Adams that I did not look prior. To be certain, I just reread the manual's material on the distributor. There is no mention concerning if or not the points are open or closed after the engine comes to rest.

Regarding the statistical record, since we now know that if there is spark at the distributer the points are open yet if the power stops at the coil the points are closed, we can now check by using a needle testor. So now every time I shut the engine down, I'll test and scratch the results in the top of the fender,

Operational manuals notoriously omit what the engineers think any operator should know or novice mechanics should know. My operators manual shows usage and notes written within which evidence the fact that I have read the content. I have learned what I know by asking for answers to MY questions,, simple or foolish as they may seem to others.

Yet because of Tim's insistence that I use the net more and before I raise a question, I now do just that. My I pad is my most valuable tool, it now is always in my reach.

In short to others, ask but do also learn how to research and thus earn a greater sense of independence.

Edited October 25, 2015 by pflaming

[Don Coatney]

PP;

When power is interrupted at the coil a running engine will coast until the exact time where resistance overcomes inertia at what point it stops turning. And the exact point the engine stops turning will most likely be different each time the power is interrupted. There is no master plan designed by the engineers on having the points open or closed when the engine stops spinning. I an rather curious why you feel this question has any relevance?

[pflaming]

It's relevant to me because I couldn't figure out why the coil was randomly "dead". Add to that, I understand the ideas of Chaucer, Emerson, Shakespeare, et al but the mechanical world is new to me. It has given me a great retirement hobby and so like "H".i don't go down easily.

[Plymouthy Adams]

pflaming, on 25 Oct 2015 - 12:40 AM, said:

Not true Mr. Adams that I did not look prior. To be certain, I just reread the manual's material on the distributor. There is no mention concerning if or not the points are open or closed after the engine comes to rest.

Regarding the statistical record, since we now know that if there is spark at the distributer the points are open yet if the power stops at the coil the points are closed, we can now check by using a needle testor. So now every time I shut the engine down, I'll test and scratch the results in the top of the fender,

Operational manuals notoriously omit what the engineers think any operator should know or novice mechanics should know. My operators manual shows usage and notes written within which evidence the fact that I have read the content. I have learned what I know by asking for answers to MY questions,, simple or foolish as they may seem to others.

Yet because of Tim's insistence that I use the net more and before I raise a question, I now do just that. My I pad is my most valuable tool, it now is always in my reach.

In short to others, ask but do also learn how to research and thus earn a greater sense of independence.

 

 

Question: when an engine is shut and is not running, will the points be open, closed, or not consistant either way?

 

 

there is no mention in the book because they cannot make that call as the engine stops where it stops and it can be any where in the revolving mass that makes up the engine and in relationship to the distributor, that is 720 degrees of rotation of the crank..  The times the coils seems dead is actually the very time it is working, thus the points are closed.     With your further explanation, now we see the validity in your question/statement.  Your original statement/question was not clear enough to point that there was a diagnostic cause and effect you trying to understand.  It seems to just be hanging out there on a limb.

[Plymouthy Adams]

AS AN ASIDE...you cannot always believe what is on the internet..some are well written..others confusing and information just flat out wrong or backwards...

[TodFitch]

I am under the impression that the engine is more likely to stop on a compression stroke as that is when there is the most resistance to motion on the crank. If one cylinder has higher compression than the rest then the engine might stop fairly consistently on the compression stroke for that cylinder. But that would vary widely from one engine to the next.

[Dave72dt]

I'll throw this thought out there to be pondered.  As evidenced by wear on the flywheel's ring gear caused by starter engagement, the engine tends to stop fairly consistently in two spots, 180 degrees from each other.

[Young Ed]

I'll throw this thought out there to be pondered.  As evidenced by wear on the flywheel's ring gear caused by starter engagement, the engine tends to stop fairly consistently in two spots, 180 degrees from each other.

I've heard that too. I heard in context of someone rotating their ring gear rather than flipping it putting the worn spot into an area where the engine won't be stopped to need to start from. 

[Dave72dt]

Not every ring gear can be flipped.  Some have a leading edge bevel cut into the teeth to help the starter drive engage and some have a bevel cut on the inside of the gear where it contacts the flywheel since some of those may have a small radius.  I've seen both on farm equipment.  turned a few ring gears a quarter turn for those not wanting to spend the money on a new gear.  Whether Mopar did or did not put in either of the bevels, I have no clue.