Another NO SPARK thread...

[Mopewbie]

Hi all. I just got this 1970 Coronet 440. Drove her home yesterday making a few stops, all good.

Today I tried to fire her up and nothing. She did try to start a couple of times but nothing. I checked spark, and it's not there.

It's the original ignition system, SINGLE WIRE distributor. NO ECU/Orange box.
I tried another coil. I tried another ballast resistor. I replaced the dizzy cap.
I cleaned points with a sandpaper.

I don't know this system at all, what else should I look for?
Coil is receiving 12v from ignition.

There is a condenser connected to the coil, could this be causing the issue? (it's in very bad shape)

Thank you for any help to sort THIS issue. Yes, I'll consider upgrading it in the future but I need this car working ASAP because it's blocking access.

 

[dadsbee]

External condenser is just a noise filter for the radio. Disconnect it, but doubt that's your issue.

 

[RemCharger]

Disconnect all unnecessary stuff from the coil. Looks like a bunch of add ons

 

[Mopewbie]

Disconnect all unnecessary stuff from the coil. Looks like a bunch of add ons

NEG - wire from the dizzy
POS - 1 wire to the auto choke and 1 to ignition (had the condenser as well but now gone)

 

[RemCharger]

Disconnect the electric choke for shits n giggles

 

[GTXDAN]

Could be the condenser in the dizzy.

 

[R413]

Did you measure the point gap? .017 is close.
How ruff of sandpaper did you use?
Are the points greasy from the cam lube?

 

[Mopewbie]

Could be the condenser in the dizzy.

Thanks, I'll see if I can get another one somewhere.

 

[Mopewbie]

Did you measure the point gap? .017 is close.
How ruff of sandpaper did you use?
Are the points greasy from the cam lube?

No, didn't measure it. Thanks for the reference.

Can'tn remember the sandpaper but it was to the smooth side.

Didn't pay any attention inside the dizzy to be honest, can't tell, I'll check tomorrow.

 

[sam dupont]

what do you get from the end of a plug wire?

 

[Mopewbie]

what do you get from the end of a plug wire?

Nothing. Had some very weak spark in the morning but not even that anymore.

 

[snakeoil24]

Internal condenser

 

[Don Frelier]

Did you check voltage in both start and run position?

 

[Mopewbie]

Did you check voltage in both start and run position?

I have not.

 

[Don Frelier]

I have not.

Likely the condenser though.

 

[gtxrt]

just take the condenser wire off the points and see if it starts that will tell you if the condenser is bad.

 

[dadsbee]

??? Did you try a booster pack vs just your low battery before you started tearing stuff apart???

 

[twecomm]

Assuming you have a good battery, and a solid ground (battery minus) to engine block as well as the car's chassis.
In a stock points ignition system it works like this....
The ignition switch, in the start-cranking position, routes full battery voltage to the coil + terminal. This is done to deliver a maximum voltage to the coil which is typically lower than otherwise during cranking due to a reduction of battery voltage because of the high current draw of the starter motor dragging down the battery by some amount. During cranking, the ignition switch electrically bypasses the ballast resistor. So, during cranking, you should see same voltage reading on either terminal of the ballast resistor as well as the + side of the coil.
When ignition switch switch is released from cranking position to the run position, the ballast resistor will now be in circuit, or electrically in series with the coil reducing the battery voltage to the + terminal of the coil, voltage will be less than full battery voltage due to resistance of the ballast resistor. In other words, in run position, one side of the resistor will be close to same as if you measured the battery, the other side of the resistor will be lower than battery voltage.
The points, when closed, complete the circuit electrically to ground thru the distributor points to ground of the engine block, which should be connected with heavy wire to battery minus terminal as well as cars chassis. When the points open, the coil de-energizes and magnetic field created within the coil primary windings collapses inducing a voltage into the secondary of the coil which, via turns ratio, significantly steps up the battery voltage to thousands of volts which is routed to the proper spark plug via the rotor and the distributor cap and plug wires to the spark plugs.
Your wiring looks like it's in less than ideal condition. Any crimp terminals that show green corrosion where the wire joins the crimp pin could be problematic. The electrical paths described for ignition switch and coil all go thru the bulkhead connector. And yes, a bad condenser can also create a problem. Inspect those connections as well.. Hope this helps...

 

[Geoff 2]

This problem could have many causes.....
- either condenser could be faulty
- open cct bal res
- corrosion of bulkhead terminals
- wiring
- coil
- carbon tracking inside dist cap
- etc

 

[Mopewbie]

just take the condenser wire off the points and see if it starts that will tell you if the condenser is bad.

didn't know that was possible, I'll try.

??? Did you try a booster pack vs just your low battery before you started tearing stuff apart???

Certainly. Definitely not battery.

Assuming you have a good battery, and a solid ground (battery minus) to engine block as well as the car's chassis.
In a stock points ignition system it works like this....
The ignition switch, in the start-cranking position, routes full battery voltage to the coil + terminal. This is done to deliver a maximum voltage to the coil which is typically lower than otherwise during cranking due to a reduction of battery voltage because of the high current draw of the starter motor dragging down the battery by some amount. During cranking, the ignition switch electrically bypasses the ballast resistor. So, during cranking, you should see same voltage reading on either terminal of the ballast resistor as well as the + side of the coil.
When ignition switch switch is released from cranking position to the run position, the ballast resistor will now be in circuit, or electrically in series with the coil reducing the battery voltage to the + terminal of the coil, voltage will be less than full battery voltage due to resistance of the ballast resistor. In other words, in run position, one side of the resistor will be close to same as if you measured the battery, the other side of the resistor will be lower than battery voltage.
The points, when closed, complete the circuit electrically to ground thru the distributor points to ground of the engine block, which should be connected with heavy wire to battery minus terminal as well as cars chassis. When the points open, the coil de-energizes and magnetic field created within the coil primary windings collapses inducing a voltage into the secondary of the coil which, via turns ratio, significantly steps up the battery voltage to thousands of volts which is routed to the proper spark plug via the rotor and the distributor cap and plug wires to the spark plugs.
Your wiring looks like it's in less than ideal condition. Any crimp terminals that show green corrosion where the wire joins the crimp pin could be problematic. The electrical paths described for ignition switch and coil all go thru the bulkhead connector. And yes, a bad condenser can also create a problem. Inspect those connections as well.. Hope this helps...

wow, that's a lot of information, thank you very much. It's so frustrating because I drove her the day before and it was working "fine". Reading about it it makes sense being the condenser, it was popping a lot and I noticed a bit of struggle going uphill. The car has been completely neglected, previous owner had no idea about cars at all. I'll be asking a lot of things in the forums for the next coupe of weeks.

sorting the wiring is definitely priority.

Thanks all so far.