'51 Desoto Custom Distributor and Ignitition

[Tim Larson]

12 minutes ago, Los_Control said:

I think it is the IAT-4012 number is all you need. Myself would write all them down and bring it with you.

I would think napa has them or can get them next day, while Bernbaum I would love to recommend and have you send your money to them ... just a matter of convenience.

 

Even if they only have the condenser in stock, I would bring it home and try it first .... what you describe I think the condenser is suspect.

At least you will find out what the problem was. If you change everything at once and it works, you never really know. It could be the coil also. And napa should have that in stock.

At least if you find out what part is bad, you can throw it away, the rest you can clean up and keep for spares in the trunk for emergency roadside repair? 

 

I ordered a tune up kit and coil from Bernbaum, but gave them the top middle number on the distributor when I placed my order. I will replaced each item separately and test - starting with the condenser - if that works then the other pieces can be saved as spares. 

 

There's no major hurry to get that car running, but I would still like to figure it out. 

[Los_Control]

I am trying to keep my truck as original as possible. Because I have no confidence in todays ignition parts, am kinda thinking to convert to petronix or possibly go 12 volt and do the slant 6 distributor hack.

Since all my driving, grocery, hardware, auto parts is within 10 blocks of my house am going to run points as long as I can. and keep a couple new condensers in the glove box.

[Tim Larson]

1 minute ago, Los_Control said:

I am trying to keep my truck as original as possible. Because I have no confidence in todays ignition parts, am kinda thinking to convert to petronix or possibly go 12 volt and do the slant 6 distributor hack.

Since all my driving, grocery, hardware, auto parts is within 10 blocks of my house am going to run points as long as I can. and keep a couple new condensers in the glove box.

 

This car belongs to a neighbor that is not mechanical at all so I am doing my best to help him keep it up to par. 

[Booger]

You keep frying condensors. No mention of remote ballast resistor 

On 5/7/2020 at 12:26 PM, Sniper said:

Inconsistent spark can be caused by a number of things.  The points, the condensor, the coil, the coil wire, the cap, the rotor, the wiring.  Basically, anything in the ignition system.

 

Let's go over each item separately.

 

The points -  nothing but a switch, when they are closed they let the coil charge up, this is the dwell.  When the open the coil fires.  In your pic the brown looking wire is the one that goes to the coil and it should be well insulated as well as the wire that goes from the the distributor to the coil +.  If either is shorted to ground you get no spark.

 

The condensor -  it's the canister looking thing with the red wire.  The condensor is used to limit arcing on the points to increase their life.  The red wire should also not be grounded.

 

The coil - the coil takes the 6v and turns it into several thousands of volts to fire the coil.  When the points are closed the coil charges up primary side, creating a magnetic field.  When the points open that magnetic field collapses and sends the thousands of volts out the primary side via the coil wire.  I have seen other brands not run right, if at all, when the coil is hooked up backwards though mine was hooked up that way when I bought it and it ran.  I've seen coil work fine cold but when they get hot fail.

 

The coil wire - takes the voltage from the coil to the cap, this wire can be back or breaking down cause lack of spark out of the cap to the plugs.

 

Cap and rotor -  just a distribution system, but if the rotor is bad or the cap has carbon tracking it can cause issues. 

 

Wiring - inspect all of it closely.  It is very common for old wiring to have the insulation physically fail and start falling off causing issues. 

 

Assuming you are wired stock (coil- is to v, coil + is to points) the following applies.

 

You need 6v at the coil - connection with the key in run or start and you need a switched ground to the coil +.  You can run a temporary jumper from the battery - to the coil - and test for spark.  This will test the source to the coil.  if there is no difference then the source is likely not the issue.

 

For the points you can run a jumper from the coil + (remove stock wires for this test) and touch the other end of the jumper to ground.  Every time you take the jumper off ground it will cause a spark.  I pull the coil wire from the cap and put a spark plug in to test here, make sure you ground the outside of the plug.  Don't leave the jumper hooked to ground for long it will heat up the coil, a couple quick on/off tests should be enough for this test.  If this makes no difference then the points are probably not the issue.

 

If you pass those two tests closely inspect the cap and rotor for issues.  If you see none there then move on to the coil.

 

Inspect the coil so signs of leakage, they are oil filled for cooling.  If there is evidence of leakage, replace it.  Look for carbon tracking or arc marks between the tower (where the coil wire plugs in) and anywhere else, other terminals, case, mounting bracket.  If yu have an ohm meter measure the resistance from the coil - terminal to the coil + terminal and from the coil - terminal to the coil tower connection.  Tell us what they are.

 

Let us know

 

 

 

[Sniper]

Ballasts aren't used in a 6v system

[Los_Control]

2 hours ago, michaelmarks697@yahoo.com said:

You keep frying condensors. No mention of remote ballast resistor 

The only person that said it was a condenser is me. This is the first time the issue has come up for the new owner.

I have no proof it is a condenser .... I  JUST HATE OFF SHORE IGNITION PARTS! I am biased and personally think this could be it.

 

I will agree your post is great and offers a lot of troubleshooting tips, I appreciate it .... but me saying it is possibly a condenser does not make it so.

TJ the original poster never said it was a condenser, and if it is it is only 1 time for new owner.

 

Just saying, with the distributor cap off, should be able to turn the engine over and points get a consistent spark. If it is inconsistent,  that cuts down 1/2 of the trouble shooting you post.

Same time saying your post is good because tj gets a good spark with the cap off and we move to the next stage.

[vintage6t]

You said the car cranks but little or no spark. One thing to check is the battery cables. Make sure they are proper 6v cables and not undersized 12v cables. Also make sure all connections including the ground are clean and making good contact. In other words when cranking do you have proper voltage at the coil? In my mind that's the first step to getting good spark.

[Dodgeb4ya]

2 hours ago, Los_Control said:

The only person that said it was a condenser is me. This is the first time the issue has come up for the new owner.

I have no proof it is a condenser .... I  JUST HATE OFF SHORE IGNITION PARTS! I am biased and personally think this could be it.

 

I will agree your post is great and offers a lot of troubleshooting tips, I appreciate it .... but me saying it is possibly a condenser does not make it so.

TJ the original poster never said it was a condenser, and if it is it is only 1 time for new owner.

 

Just saying, with the distributor cap off, should be able to turn the engine over and points get a consistent spark. If it is inconsistent,  that cuts down 1/2 of the trouble shooting you post.

Same time saying your post is good because tj gets a good spark with the cap off and we move to the next stage.

I also hate junk , waste of time offshore ignition points, never work condensers and loads of other crap for us to test on our cars...I won't buy any of it anymore....ever.

I use only old stock....ignition parts...always works...always.

Rant over.

 

[Dodgeb4ya]

How about forgetting the ignition...put it all back together.

Keep the choke open..

Give the carb a small shot of "Good" ether...

See if it will even try to start or pop off.

[Tim Larson]

16 hours ago, vintage6t said:

You said the car cranks but little or no spark. One thing to check is the battery cables. Make sure they are proper 6v cables and not undersized 12v cables. Also make sure all connections including the ground are clean and making good contact. In other words when cranking do you have proper voltage at the coil? In my mind that's the first step to getting good spark.

 

The car does have proper 00 gauge cables. I will check connections.

 

The battery must be fine because I used it to start a '49 Plymouth that was otherwise not starting with the battery that was in that car.

[Tim Larson]

15 hours ago, Dodgeb4ya said:

How about forgetting the ignition...put it all back together.

Keep the choke open..

Give the carb a small shot of "Good" ether...

See if it will even try to start or pop off.

 

I did put everything back together - there is plenty of fuel spraying into the carb.

 

I could try ether before replacing other parts.

 

Hopefully will have an update this next week sometime.

[Dodgeb4ya]

The engine intake might be flooded with fuel...open the throttle and look down there.

[Tim Larson]

Just now, Dodgeb4ya said:

The engine intake might be flooded with fuel...open the throttle and look down there.

 

I will check this.

 

Would this evaporate or does it stay pooled in the intake for a longer span of time?

[Dodgeb4ya]

It can sit there for a long time on a cold engine....it will be a puddle if down there....plugs can be will be wet or dry ...I have been thru this,,,worth checking out.

I understand maybe a weak spark but it did run fine till it sat and incorrect after sitting start procedure can get you into this situation.

If it is flooded... leave the throttle open for  few hours or a day...put throttle back to closed .... a pump or too and try cranking it... hopefully it will start up.

[Tim Larson]

1 minute ago, Dodgeb4ya said:

It can sit there for a long time on a cold engine....it will be a puddle if down there....plugs can be will be wet or dry ...I have been thru this,,,worth checking out.

I understand maybe a weak spark but it did run fine till it sat and incorrect after sitting start procedure can get you into this situation.

If it is flooded... leave the throttle open for  few hours or a day...put throttle back to closed .... a pump or too and try cranking it... hopefully it will start up.

 

The plugs were all wet/damp when I checked them a couple of days ago.

 

It had run fine right before I changed the oil and filter last October and then it didn't seem to want to fire at all.

It is probably flooded right now.

I'll have to check this out.

 

Thanks

[Tim Larson]

Assuming the intake manifold has a lot of fuel pooled in it. Would it be reasonable to remove all of the spark plugs to allow fuel pooled in the cylinders to evaporate?

[Dartgame]

That would help, but with one change, crank the engine to suck fresh air into the manifold and cylinders.

 

My assumption is you have a bad  condensor - I've used the junk available in the aftermarket and had a failure similar to what you are describing. Bad coil will do similar things too.

[Dodgeb4ya]

The plugs need to be tan color and dry.

Are you checking for spark at the end of the coil lead 3/8-1/2" from the block or other meal ground while cranking?

Or at the grounded spark plug....possibly wet with fuel ?

Spark should be a snapping 3/8" blue spark from the coil .

[Tim Larson]

6 hours ago, Dodgeb4ya said:

The plugs need to be tan color and dry.

Are you checking for spark at the end of the coil lead 3/8-1/2" from the block or other meal ground while cranking?

Or at the grounded spark plug....possibly wet with fuel ?

Spark should be a snapping 3/8" blue spark from the coil .

 

I have not had a chance to check spark at the coil lead or the plugs yet. They appear to be wet with fuel.

Looking down the carb today with the throttle open I could see plenty of fuel sitting pooled.

 

I'm planning to do some more testing after work these next couple of days.

 

Thanks for the input.

[Tim Larson]

Well, I got all the parts today and tried to tackle this project.

 

Points, condenser, rotor, cap, coil and plugs all replaced - still nothing. I also replaced the wire from the coil to the points.

 

There does seem to be spark at the points and the plugs.

 

I think the car might be so flooded with fuel that is causing at issue. There is still quite a pool below the carb. We removed all plugs and cranked the engine, but did not see any fuel come out the plug holes - my grandpa does this on his tractors when they are flooded to get the fuel out of the cylinders.

 

I left all the plugs out and have the throttle and choke open. Tomorrow I will go see if any fuel evaporated.

 

The car did fire just briefly when starting fluid was sprayed while cranking, but not after the first time.

 

I checked and there is current at the + and - side of the coil when the key is on and also at the points when they are closed.

 

Could the semi-automatic transmission cause any issues with starting? It looks like some the wires in that setup connect to the coil and carb. but I don't fully understand how that system works. I did reconnect all wires at the coil exactly as they were.

 

[greg g]

The wires to the carb for the tranny are for kickdown to a lower gear on demand and an IGN ground to momentarily ground the coil to provide a moment of driveline slack during the up shift.  One of those wires does go to the coil so make sure it is not grounding any where. If it's not connected to the carb it shouldn't be a cause of your trouble but who knows. If you have spark at the points it should be firing if the coil is good, if the rotor and cap are correct for the dist. Have you tried checking for spark at the dist end of the coil wire?  Pull it from the dist and hold it near a head hold while cranking.  Use insulated pliers or heavy rubber gloves.  If you have spark there the fault is located between there and the plugs.

 

[Tim Larson]

10 minutes ago, greg g said:

The wires to the carb for the tranny are for kickdown to a lower gear on demand and an IGN ground to momentarily ground the coil to provide a moment of driveline slack during the up shift.  One of those wires does go to the coil so make sure it is not grounding any where. If it's not connected to the carb it shouldn't be a cause of your trouble but who knows. If you have spark at the points it should be firing if the coil is good, if the rotor and cap are correct for the dist. Have you tried checking for spark at the dist end of the coil wire?  Pull it from the dist and hold it near a head hold while cranking.  Use insulated pliers or heavy rubber gloves.  If you have spark there the fault is located between there and the plugs.

 

 

We checked and there is spark at at least two of the plugs. It looks like it should be hot enough spark to ignite the fuel.

 

The old plugs I took out definitely smelled of fuel, but not fresh fuel.

[Sam Buchanan]

9 hours ago, tjlarson88 said:

 

The old plugs I took out definitely smelled of fuel, but not fresh fuel.

 

So.......are you using fresh fuel?

 

The shelf life of ethanol-contaminated gasoline can be pretty short and stale gas can definitely result in start-up difficulty. The ethanol can also absorb water.

Edited May 14, 2020 by Sam Buchanan

[Tim Larson]

9 minutes ago, Sam Buchanan said:

 

So.......are you using fresh fuel?

 

The shelf life of ethanol-contaminated gasoline can be pretty short and stale gas can definitely result in start-up difficulty. The ethanol can also absorb water.

 

The tank should have been full when parked last fall and then a fuel stabilizer was added. 

 

This starting issue began late last year and the fuel should not have been old enough at that time. 

 

I will pump the fuel out of the intake where it is pooled if it has not evaporated by this evening. 

 

Hopefully I will have some sort of update by tonight. 

[Tim Larson]

Also, I wondering about the strength of the spark. 

 

With 6 volt will spark not be a bright or hot as 12 volt? 

 

The spark I could see at the plugs almost looked more yellow/orange to me, but I could be wrong. 

 

I suspect the fuel sitting in the intake could be a lot of the issue. 

 

Like I said, we sprayed a bit of starting fluid into the carb. while cranking and it did briefly fire, but only once or twice. My grandpa was helping and didn't want to get carried away with starting fluid. He's 86 and has been working on/around tractors/cars since he was in his 20s/30s, at least, so I trust his judgement.