No spark

Hi,

Remove the distributor cap and with the ignition on, take a screwdriver and gently open and close the points to see if there is power to them. You should see a spark. Also, let me know if you are confident the points are properly gapped.

Remember, the fixed side of the points is grounded along with the condenser. Make sure nothing is preventing that. Also, the movable side should be to the negative side of the coil, so check that as well.

I do have a question. Was the vehicle running prior to replacing the points and condenser? I have seen different style points be set up differently than the OEM. Some have insulators in different places which cause a break in the circuit, so make sure to closely inspect and compare them.

Please understand, because of the model year, I have very little information on this vehicle, but I will try my best to help.

Let me know.

Joe

Okay, no spark from the points. The only wire coming from the distributor is on the negative side of the coil.
Before changing the points and condenser, it wasn't running because of a clogged fuel line. Unclogged the fuel line and still didn't run. Before the fuel line issue it did run and it shut down like shutting of the key. I checked for spark after the fuel line was fixed. It had a bright red spark. Car didn't even sputter. I checked for spark again and nothing at all. That's when I changed the points and condenser. Nothing there so I changed the coil. Still nothing. Is there a power supply that goes into the distributor??

If you are getting nothing at the points (power), go back to the negative on the coil. With the engine on, is there power? If there isn't, check the positive side of the coil. Is there power? With the key on, you should see it on both sides. The points are what complete the circuit when they close. When open, the power jumps to the condenser.

Note: If there is no power to the + on the coil, run a jumper wire between the battery and the + on the coil and see if it starts. If it does, then we need to work back to the ignition switch to see where power is lost.

If it does start with a jumper, only run it for a very short time. If the points are getting 12v, you will burn them up somewhat fast.

On the other hand, if you don't want to try the jumper wire, then we need to trace the wire to the + on the coil back to see where there is an open circuit.

Let me know what you find.

Take care,

Joe

I have power on both sides of coil when the points are closed. No spark at all when opening the points. I changed the condenser with 2 new ones no difference. I went as far as buying 2 new coils. Plenty of power but not a spark to be seen.

Did you replace the points? You should be getting power to them. If you aren't, that is the problem. I have seen the wire inside the insulation break from movement (vacuum advance) and cause a no spark issue.

Check at the points for power. If there is none, wiggle the wire to see if you get anything. If you have power out from the negative side of the coil, it should be at the points.

Here is how it works: When the points close, electricity runs from the battery, through the coil, and to the ground. When the points open and power can no longer go straight to ground, the electricity, which by nature seeks the easiest path to ground, jumps to the secondary circuit to the coil wire to the top of the distributor cap where it is transmitted to the distributor rotor.

So, you must have power to the points with the key on. If there isn't power, then we need to determine where the open circuit is located.

Let me know what you find or if you have other questions.

Take care,

Joe

There's power to the points. Yes, the points are new. The spark isn't happening. Power is everywhere it needs to be. I replaced all the plug wires also.
I suspected that the ground wire from the coil was bad so I replaced it. New wiring, plugs points, condenser, coil, still no spark. What am I missing?? The ignition system on the old vehicles is so simple it has to be something that's getting overlooked..

If you have power to the points, they are properly gapped, and the coil is good, you should have spark. We are missing something simple. Are you sure the new points (where the wire attaches to it) aren't grounded due to a plastic washer missing? How did you gap them? If you remove the cap and have someone crank the engine, are the points opening/closing? Once the points open, the easiest way for the power to leave the coil is via the secondary circuit (coil wire to distributor). From there, the rotor distributes it to each cylinder in a timed format.

Joe

The points open and close when the engine is turning over. They were set using a feeler gauge. Manufacturer calls for the points to be set.

Set between.014 -.016. I set them at .015. I'm going to check the coil again.

At my wits end with this Jag.. I called a mechanic to work on it. I'll find out what is the issue and pass it on to you.. Perhaps hel

Perhaps help someone else in the future who might have the same issue as I have.

Hi,

I would appreciate that. Somewhere we are losing power to the points or there is a short to ground. I'm really interested in knowing what is found.

Joe