No spark

Hi,

Because of the model year, I have no schematics to work with. So, I have a few questions. First, I believe in 1973 you have a single coil and points and condenser in the distributor. Is that correct?

If you lose that much power with the coil connected, it could be due to an internal short in the distributor, or the wiring to it can have a faulty connection or is broken internally (under the insulation).

When you connect it and it drops, wiggle the wire supplying the power to see if the voltage is consistent or if it fluctuates.

If it doesn't change, we need to confirm there isn't an internal short in the coil. You will need a digital multi-meter (DMM). To check it:

1) Disconnect all wires to the coil.

2) Turn the DMM to ohms to identify resistance.

Primary Resistance Check

3) Primary Resistance check: Touch the red DMM terminal to the + side of the coil and the black terminal to the - side of the coil.

4) Expected Resistance: Many manufacturers indicate variations in the acceptable range, but in most cases, resistance will fall between 0.4 and 2.0 Ohms.

Secondary Resistance Check

5) With the coil still disconnected, place the DMM red terminal on the + side of the coil.

6) Place the DMM black terminal to where the coil wire would go (coil tower).

7) Expected Resistance: Many manufacturers indicate variations considered in the acceptable range. However, in most cases, resistance will fall between 6K and 15K Ohms.

I tried to draw a couple of pics below to help identify where the wiring goes from the DMM.

If the readings are far from what I indicated, I suspect the coil is shorted internally and needs to be replaced.

Let me know if this helps.

Take care,

Joe

See pics below.

Hi,

I suspect power comes from the ignition switch on this model year. I don't have schematics to confirm that.

Let me know if the kit you purchased makes a difference.

Take care,

Joe

Hi,

That would be a good indication that the switch is good. The module is a different issue. Something as simple as a failed ground can be causing issues.

Let me know how it turns out for you. Also, let me know if I can help in any way.

Take care,

Joe

Hi,

Because of the model year, I don't have the diagnostics for the module. I'm somewhat embarrassed to ask, but does the vehicle still have points? I believe the kit you added should eliminate them, but on the other hand, the vehicle would have come with points and a condenser. Sorry, it's been a long time since I dealt with one of these.

Let me know as much as you can.

Joe

Hi,

Welcome back. If you are getting 0 Ohms between the positive and negative sides of the coil, it does sound bad. It should be between 0.4 and 2.0 Ohms.

Do you have a coil you could switch it with just to try?

Joe

Hi,

It sounds like I have luck as I do. As far as the coil is concerned, it should be hooked up like any other coil. I have no schematics to reference, so is it possible for you to take a few pics of what you are dealing with and upload the for me to see? Also, does this vehicle still have points and a condenser in the distributor?

Let me know.

Joe

Hi,

Because of the model year, I'm having issues finding the info we need. However, what I do suggest is to check the fuel pressure and also confirm the fuel injectors are getting power and a ground path.

If they are getting power and have the correct fuel pressure, take a look through this link. It explains how to test an injector.

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

Let me know.

Joe