73 240 No spark

[Patcon]

I am wondering if the distributor is grounding

[Captain Obvious]

11 hours ago, Shawninvancouver said:

something is wrong in the yellow circle area.. as only green.wt goes to resistor..  i have now followed those instructions and possibly wrong..please clairify the correct wiring..

There is nothing wrong in the diagram. It shows the correct wiring.

So can you please put the wiring back like it was shown in this pic and hotwire the thing? One wire on one side of the resistor goes to the coil (+). One wire on the other side of the resistor goes to the battery (+).

Crank the car. See what happens.

[Shawninvancouver]

Hi captain.  I will try that jumper test. My main question is do you not think the green white needs to be connected?? And why in the fsm it shows the two wires going go the resistor are a green wt and a black wt from harness and the only black wt going to positive on coil also comes from harness.  ??

[Captain Obvious]

The G/W does not need to be connected at all if you hotwire it as I described.

And about your other question... Some of the connections shown in the FSM diagram are made inside the harness. That diagram is a good functional description of how the system works, but it can be a little confusing if you are looking at the wires coming out of the harnesses.

For example, the connection between the G/W and the tach is made in the harness and you don't have to tie that together manually. It's already done. When I get a chance, I'll try to whip up a sketch showing the connections in a different form. Still the same electrically, but drawn differently.

In the meantime, just simplify stuff! Take all the wires off everything and hotwire the durn thing. Let's try to figure out if your distributor works!!! 

[240dkw]

As well, have you confirmed that the points are fully closing and opening while you are cranking it? 

[Shawninvancouver]

YES 240DWK, points open and close.. i tried 3 dizzys all points gapped correct..   i have once again attached a few diagrams trying to figure out proper wire connections..  i am hoping im just mixing up the connections... the red one was posted in this thread,, and shows greenwht to resistor then to coil +  yes Capeeetain - i know the greenwt will not need to be connected if hot wired... i was first attempting to do it the right way with out wires running across engine...  i will try the hot wire method to see what happens... it if that works what does that mean? one of the wires is dead along the way somewhere/in the harness?? the main reason i think wires were always wrong is that  i always had a wire going from resistor to coil +   is that correct or wrong???  **USING A PETRONIX FLAME THROWER COIL **

the fsm is totally different.. can someone explain these two diagrams...  i just need the proper connections...

 

Edited May 2 by Shawninvancouver

[Zed Head]

3 hours ago, Patcon said:

I am wondering if the distributor is grounding

Maybe it would help to back up and do more of the basics. 

1.  Use your meter and set it to resistance or continuity.  Place one probe on the engine block and the other on battery negative.  This will confirm a good circuit from the battery through the engine block (Patcon's point above).  You've already confirmed positive (power) but have not confirmed the return path, the ground.

2.  Place a probe on the distributor body by the points and the other on the engine block, or even back to the battery negative.  Confirm that the path is low resistance/continuous.  This will confirm a good path from the distributor body back to the battery.

3.  Place a probe on the negative side of the points (the side with no wire connected to it) and the other on the distributor body, the engine block, and battery negative.  This will confirm an unbroken path from the points back to the battery negative.

4.  With the key off and the points open, place a probe on the coil negative terminal and the other probe on the engine block or battery negative.  Confirm that the circuit is open, non-continuous, very very high resistance.  You might have a short to ground from the coil primary circuit.  With the key off and points open the coils two posts should not have a path to ground.

 

There will be no spark created if the coil is never de-energized (short to ground).  There will be no spark if there is no current flowing (open circuit to ground).  The presence of voltage does not guarantee current flow.  An open ground circuit or a short to ground, on the coil circuit, will cause a no spark situation.

 

 

[Yarb]

Still haven’t heard the results of @Captain Obvious suggested. Takes less than five minutes 

[Zed Head]

Here's another thing that I had thought about earlier - is the distributor rotor turning when the engine is turning? Might be that all of the wiring is just fine but the points never open and close because the distributor isn't turning.  You can check that by eye.

You can also leave the distributor cap off while turning the engine and watch for spark across the points themselves.  Maybe the coil is bad.

[Shawninvancouver]

yes captain.. checked that..  points open and close on turning..  also was checking for spark before the distributor by holding plug wire out of middle of coil to engine block.. no spark... thats why i think its at the coil.. 

i will try all grounds tomorrow.  yarb..car is not in my garage.. at a pals.    i will check all grounds.. but i tried 3 dizzys..  so one must have been ground ok.. maybe main ground or coil ground...  this is taking more time then i thought,,,,

still looking for confirmation or wiring though.. any thoughts on wires to and from resistor?

Edited May 2 by Shawninvancouver

[240dkw]

I don’t think there should be a wire directly from the resistor to the coil, power should be on the b/w to the resistor when the key is in the “run” position and on the g/w when the key is in the “start “. And of course power at the + wire on the coil with the key in either position. And these measurements are at the end of the wires disconnected. Will not read 12 volts if connected to the coil or resistor, it will be lower due to voltage loss through the system.

Edited May 2 by 240dkw
Added last comment after testing it on my car.

[DatsunZGuy]

It might be worth the expense to locate a mobile mechanic in your area and have them make a house call.  Sometime having another person to bounce ideas off of may result in a breakthrough. 

Also...

Are you in Vancouver WA or BC?  Perhaps a member of a local Z club live nearby that could lend a hand.  It might be worth searching online for one.