'51 Desoto Custom Distributor and Ignitition

[Tim Larson]

On 5/7/2020 at 11:38 AM, Loren said:

 

Connect the alligator clip to the points side of the coil and the ice pick to the ground side of the battery.

With the ignition on roll the engine over. If by hand you will see the light go on and off. If by the starter it will flash. When the light is on the points are open. When the light is off the points are closed and the coil is being energized. When the points open the magnetic field in the coil collapses and the secondary creates the spark. So you can check the timing by observing when the timing mark comes up and the light goes on.

 

 

We tried this last night, but the test light did not seem to blink of flash at all.

 

I know the points were opening and closing.

 

I will try this again today. 

 

Rolling over by hand would just involve wrenching the engine over, correct? Turning the fan does not cause the engine to turn over. 

[Los_Control]

14 minutes ago, tjlarson88 said:

Rolling over by hand would just involve wrenching the engine over, correct? Turning the fan does not cause the engine to turn over. 

If you have the correct size socket to fit on the crank bolt,  Always a good idea to turn it in the normal direction as if the motor was running.

In my experience, often you can just push on the fan belt applying pressure with one hand and spin the fan with the other.

What you are fighting is compression. You do not need plugs installed to check spark. The plugs are pretty easy to remove on these engines. And ultimately you want to see spark at the plugs. lay them on the head and crank the engine and check for spark.

IMHO, pulling the plugs so you can roll the engine over easily not a terrible waste of time.

Edited May 14, 2020 by Los_Control

[Tim Larson]

1 minute ago, Los_Control said:

If you have the correct size socket to fit on the crank bolt,  Always a good idea to turn it in the normal direction as if the motor was running.

In my experience, often you can just push on the fan belt applying pressure with one hand and spin the fan with the other.

What you are fighting is compression. You do not need plugs installed to check spark. The plugs are pretty easy to remove on these engines. And ultimately you want to see spark at the plugs. lay them on the head and crank the engine and check for spark.

IMHO, pulling the plugs so you can roll the engine over easily not a terrible waste of time.

 

That's a really good point that I didn't think of. The plugs are all out right now. I will try this again to see.

Thanks

[Loren]

Just to be clear, the test light goes on when the points are open. It won't flash unless the crank is turning. If the points are in solid contact for some reason (such as being closed or so tight they never open from a worn rubbing block, or a "spike" of transferred metal) the light will not go on. If the light does not light you will get no spark. You can double check what is going on by manually opening the points with a screwdriver when they are closed. Be careful as the coil will spark each time you open them. If the light goes on steady then the points are not closing. That can be caused by dust turning to glass between the points from the spark when the points last opened. (rare but it does happen)

The components on the primary side are the points, condenser and ignition coil. If the test light test does not light with the screwdriver method, put the test light on the  ignition switch side and see if you have power to the coil. Worn points are the number one reason you don't get spark on the primary side.

Assuming you've got a working primary side then you go to the secondary.

A cracked rotor or cap will discharge the spark to ground. A bad coil wire will stop the spark before it gets that far. Spark plug wires usually fail one at a time unless someone has disturbed them, then they can all be junk.

You can fix an ignition system one fault at a time but old time mechanics for customer satisfaction used to change everything for insurance. Points, Plugs, Condenser, Cap, Rotor and wires were pretty standard fare.

 

The "Battery/Coil" ignition system is pretty basic and easy to deal with. Charles Kettering of Dayton Electric Company (Delco) invented it and when Billy Durant bought Delco for General Motors, Kettering came with the deal. Kettering also came up with the "Self Starter" and Tetraethylead anti-knock compound. We don't use that anymore because it is toxic in the extreme but you can still see its remnants in the bottom of the oil pans of older cars. That grey muck is lead. Something you won't see much of in the future.

[Los_Control]

8 hours ago, tjlarson88 said:

we sprayed a bit of starting fluid into the carb. while cranking and it did briefly fire,

I hate starting fluid and suggest to never use it.

For troubleshooting it is awesome. If you spray some and it tries to fire,  You now know you have spark and your issue is fuel delivery.

From here going forward, I would be looking at fuel. Remove the line from the carb and visually see it pumping fuel. These old cars we do not know what a past owner did.

Very possible the fuel lines are clogged up from crap sitting in the tank. The diafram  in the pump could have failed, the carb may need to be rebuilt. First thing is to verify fuel going from the pump to the carb.

[Los_Control]

A fwiw post, I have seen cars sit for months or years, and the fuel pump not pick up and work, last time was a 57 cheby with a 283. Once I started it running off a gravity feed tank, the original pump started working after a few minutes. I think this is caused from a small hole or a weak diaphragm. My neighbor has a 62 cheby with same issue. Have to feed it fuel until it gets going.

I told him he needs a new fuel pump, I think he is waiting for me to come over and replace it.

 

Point is, if you can add fuel in the carb and get it to run, you need to look in this direction.

I know on my 49 dodge, I pulled the distributor and later found when I installed it I had a different issue. My intake seemed to have a lot of fuel sitting in the bottom.

Once I fixed the firing order, it fired right up and ran ok since.No clue if my intake today still has fuel sitting in it, but I would not worry about that.

[Tim Larson]

The carb is definitely getting fuel. It sprays every time you pump the accelerator.

 

There was still a large amount of fuel pooled in the intake and I tried to syphon it out, but it’s too far down in there.the car has tried to fire many times today, but just won’t take off.

 

I verified that there is spark at the points side of the coil when turning over.

 

The battery cables are 00 and connections are clean.

 

I am charging the battery now. 

[Tim Larson]

The car is running! I charged the battery for a little while and kept cranking off and on and it finally went. I almost wonder if the carburetor wouldn’t benefit from a rebuild

[Los_Control]

24 minutes ago, tjlarson88 said:

There was still a large amount of fuel pooled in the intake and I tried to syphon it out, but it’s too far down in there

I am just saying my issue, po moved the oil pump which caused the firing order to be off ... So when I yanked the wires willy nilly and replaced them, distributor was wrong.

And the truck would not start. I went through the carb thinking that could be a issue. While I had the carb off, I noticed there was a pool of fuel sitting in the intake.

I was worried about this. Once I fixed the firing order, it started right up and I never checked to see if still a pool of fuel in the manifold.

Just saying I have seen this, I would ignore it and move forward, not your issue.

 

[greg g]

The wetness at the base of the carb suggests a stuck open needle seat valve or a too high float setting or a float hanging up and not closing the needle or a float with a pin hole leak so it fills with fuel and doesn't float.  Get some new spark plugs installed after you sort the issues.

[Los_Control]

I would more suspect the fuel pump not delivering like it should.

[Sam Buchanan]

13 hours ago, Los_Control said:

 

 

 text deleted

Edited May 15, 2020 by Sam Buchanan

[Dodgeb4ya]

I think all the engine was severely flooded.

It probably was flooded by trying to start it the 1st time this spring...incorrectly, choke set too rich, choke stayed closed, pumping the pedal too much on and on.

Then all the more cranking possibly with the choke closed the whole last month trying to start it.

Pulling the plugs out...opening the choke and throttle plate ..a couple brief starts helped get rid of some excess fuel and continuous cranking finally cleared it up enough to start.

The choke plate operation probably needs to be looked at upon a cold start. Jmo..

Early 70's 318,360's were notorious for having this same cold start flooding issue if they sat.

Numerous service bulletins on those. 

 

 

[Sniper]

5 hours ago, Dodgeb4ya said:

I think all the engine was severely flooded.

 

 

 

 

 

 

This right here. OP says fuel was pooled in the intake.  Even after sitting for hours/days.

 

Carb is obviously wet with fuel on the outside.

 

OP says plugs smelled of gas.

 

Why are we fiddling with spark?

 

Rebuild the carb, get a new float.  These carbs are real simple.

 

My carb rebuild writeup

 

http://www.yourolddad.com/carb-rebuild

 

[Tim Larson]

I do think that the carb. and flooded intake may have been the issue all along. The car will benefit from the new ignition parts and it runs very well now. 

 

One issue it has had ever since purchased is that sometimes when stopping and the semi-automatic transmission shifting back to low (1st gear) the car will die, but easily restarts. Is it possible something is not adjusted properly or would this be a separate electrical connection issue?

 

I will encourage a carb. rebuild/adjustment in the near future. 

 

Thanks everyone - this was a good learning experience. My neighbor is thrilled.

[Dodgeb4ya]

The carb might be just fine..the car needs to be driven for awhile to see how it performs before doing any more repairs.

After all it did drive fine hundreds of miles upon it's purchase.

[Tim Larson]

3 minutes ago, Dodgeb4ya said:

The carb might be just fine..the car needs to be driven for awhile to see how it performs before doing any more repairs.

After all it did drive fine hundreds of miles upon it's purchase.

 

That is a good point. I'll probably wait and see if my neighbor has any problems going forward. 

[Los_Control]

Sometimes they listen, sometimes not.

Last year I worked on my neighbors 54 Ford that had a overheating issue ... I fixed that and now it needs a decent tune up. Has a 1990's 302 with FI/AOD trans.

Since it had been parked for 12-16 months, I asked him to just drive it and burn the existing 1/2 tank of gas out, put in some fresh gas and drive it some more. Then I will work on a tune up with the fresh gas. It was very drive able, would smoke the tires by accident. Just had a occasional stumble. But year old gas.

I drove it over to his house and parked it last summer, has not been started or moved since. Now I really have no desire to work on it again ...

 

Cars sitting is the biggest enemy of them .... they want to be driven to keep them working, and today's fuel is terrible.

[Tim Larson]

2 minutes ago, Los_Control said:

Sometimes they listen, sometimes not.

Last year I worked on my neighbors 54 Ford that had a overheating issue ... I fixed that and now it needs a decent tune up. Has a 1990's 302 with FI/AOD trans.

Since it had been parked for 12-16 months, I asked him to just drive it and burn the existing 1/2 tank of gas out, put in some fresh gas and drive it some more. Then I will work on a tune up with the fresh gas. It was very drive able, would smoke the tires by accident. Just had a occasional stumble. But year old gas.

I drove it over to his house and parked it last summer, has not been started or moved since. Now I really have no desire to work on it again ...

 

Cars sitting is the biggest enemy of them .... they want to be driven to keep them working, and today's fuel is terrible.

 

He will definitely drive it now that it is running. There was some fresh gas put in last night too. 

[Sniper]

Sorry, if the outside of the carb is wet with gas then the carb is not fine.  What it is is a fire waiting to happen and that would be a shame. 

[Dodgeb4ya]

Carbs get wet with gas endlessly attempting to start an engine.that won't start.

Pumping the starter too many times...some observation information given maybe a little incorrect...

If the car  (engine) is driven for a week or more with out any trouble or a drizzly wet carb and runs well.. run it.

Have some fun with the newly acquired car then decide if more needs to be done with it.

Over pumping the throttle  ten times will always wet the outside of the carb.

The engine won't run or idle with a leaky needle and seat. Black smoke loading up stalling etc.

If that is the case then properly clean and rebuild the carb.

Otherwise I'd leave it alone.?

 

 

[Sniper]

Gotta disagree, if you read my carb rebuild link you will see I noted my carb leaked externally.  It wasn't a case of my over pumping the pedal, one pump and a quarter open then fire it up.  Only issue I had.  Rebuilt it and now it does not leak externally.  In my case it looks like the inlet needle tip was the culprit.  There is a pic of it in the link.  Also the screws holding the sections together were loose.

[Dodgeb4ya]

That's good that you fixed your carb.

Sounds like it needed repairs.