240z electronic ignition help

[vantage]

I thought we are competing for the longest dialogue in a single topic thread on hybridz, no?

[Mikez31ss]

We're probably in the top 5.

* Also, is there an disconnected black/white or green/white wire next to the coil/ballast somewhere?

In case you missed it in my last reply there is both along with a green wire. None had voltage. Maybe they don't need voltage? Maybe connecting one of them to the coil negative would supply a signal to the tach?

If you remember there was also a black/yellow with 12v ignition on. I used that for the efan controller.

[Leon]

 

Leon...I've only got the brake booster port. When I remove the carbs I could probably drill a port in the manifold. Looks like a boss is there on #2. Is it a good idea to run that hose into just one cylinder? I guess if the blowby clears up it wouldn't make much difference.

 

I have a catch can left over from my 300zx cars but it's a pretty janky part.

 

I don't think it should be a huge deal, that's where my other tapped hole is I believe. The hole would be close to the balance tube anyway, so I don't think the effect will be detrimental to performance, and likely to the contrary, be beneficial. It's what I'm planning to do with my triples, so hopefully it works fine that way.

 

 

You can use a Coke can as a catch can if you want to. No big deal there.

[vantage]

From what you have posted about the wiring, my assumption would be this:

 

• Green: was connected to Coil (+) and the capacitor (still connected to the capacitor?)
  
• Green/White: was connected to left side of the ballast resistor, comes from the ignition start position and one side of the white tacho loop
  
• Short Black/White with female connector: was connected to Coil (+), comes from the other side of the white tacho loop
  
• Longer Black/White: was connected to right side of ballast resistor, comes from ignition run position (should be in a black cable sleeve, is it?)
  
• Black: was connected to Coil (-), comes from the points/distributor.
  

Still unsure about black/yellow, this is not on my '72 240Z and not in the later wiring sheets.

 

You said that the Green/White wire has continuity with the Black/Yellow, so i suppose that the Black/Yellow is the same as the Black/White coming from the ignition key run position.

 

 

Ok, now you need to identify the correct Black/White wire coming from the tach connector:

 

1. Remove the connector from the tach and use the meter in Resistance/Ohm/Ω setting
   
2. Connect one test lead to the Black/White wire in the connector and the other one to the short Black/White wire with the female connector, if this is the right one you should see 0-2 Ohm. If not check out the long Black/White wire instead.
   

If you found the correct Black/White wire, then reconnect the tacho to the tacho connector and measure the Black/White wire in the engine compartment against ground. It should show the same voltage as the Green/White wire, about 12V if the ignition switch is in the run position, and no voltage, if the ignition switch is off.

 

If so, then connect the Black/White wire you have just identified to Coil (+), instead of the current +12V supply wire. This should do the trick, you should now get +12V via the tacho loop to the coil and E12-80 ignition module.

[vantage]

This is how your final wiring should look like

[Mikez31ss]

From what you have posted about the wiring, my assumption would be this:

 

• Green: was connected to Coil (+) and the capacitor (still connected to the capacitor?)
  
• Green/White: was connected to left side of the ballast resistor, comes from the ignition start position and one side of the white tacho loop
  
• Short Black/White with female connector: was connected to Coil (+), comes from the other side of the white tacho loop
  
• Longer Black/White: was connected to right side of ballast resistor, comes from ignition run position (should be in a black cable sleeve, is it?)
  
• Black: was connected to Coil (-), comes from the points/distributor.
  

Still unsure about black/yellow, this is not on my '72 240Z and not in the later wiring sheets.

The green wire was cut and taped up (with the green/white and black/yellow)...it wasn't connected to the noise suppression condenser. There was no condenser.

You said that the Green/White wire has continuity with the Black/Yellow, so i suppose that the Black/Yellow is the same as the Black/White coming from the ignition key run position.

There is no black/yellow wire shown in the factory diagram so everything about that wire would have to be a guess. It was a 12v ignition on wire and I cut it on the passenger side of the harness and used it for my efan controller "ignition on" source.

Ok, now you need to identify the correct Black/White wire coming from the tach connector:

 

1. Remove the connector from the tach and use the meter in Resistance/Ohm/Ω setting
   
2. Connect one test lead to the Black/White wire in the connector and the other one to the short Black/White wire with the female connector, if this is the right one you should see 0-2 Ohm. If not check out the long Black/White wire instead.
   

If you found the correct Black/White wire, then reconnect the tacho to the tacho connector and measure the Black/White wire in the engine compartment against ground. It should show the same voltage as the Green/White wire, about 12V if the ignition switch is in the run position, and no voltage, if the ignition switch is off.

 

If so, then connect the Black/White wire you have just identified to Coil (+), instead of the current +12V supply wire. This should do the trick, you should now get +12V via the tacho loop to the coil and E12-80 ignition module.

I'm not following you there Adrian. There is only one black/white wire in the coil area w/ 12v. The longer b/w with the black cable sleeve. The shorter one has no power at any time.

[vantage]

Hi Mike,

 

the black/white wire connected to the coil with the black cable sleeve comes from the ignition key 'run' position, so the shorter black/white one with the female connector is most probably the one we are looking for!

 

Here is a quick and simple test: put the meter in resistance mode and connect one probe to the green/white wire (currently taped) and the other one to the short black/white with the female connector.

With the tacho connected you should see 0-2 Ohm. If you now disconnect the tacho connector behind the dashboard, you should see infinite (e.g. no) resistance.

 

If thats the case you have identified both wires coming from the tacho loop! Let me know how this works out, then we can continue to wire up the tach.

[Mikez31ss]

I haven't given up on this but I need to find a better meter. Mine is just giving various readings.

[vantage]

You can also use your test light:

 

Make sure that the tacho is connector to the tacho, switch on the ignition power and

 

1. Connect the test light to ground and (taped) green, it should not light up (if it does, skip the other tests)

2. Connect the test light to ground and black/white, it should not light up (if it does, skip the other tests)

3. Connect black/white to ground. Connect one side of the test light to battery (+), the other side to the green wire -> the test light should light up

4. Remove the tacho connector from the tacho and repeat 3 -> the test light should not light up

 

If 3. & 4. are positive, you have identified the tacho wiring

[Mikez31ss]

You can also use your test light:

 

Make sure that the tacho is connector to the tacho, switch on the ignition power and

 

1. Connect the test light to ground and (taped) green, it should not light up (if it does, skip the other tests)

2. Connect the test light to ground and black/white, it should not light up (if it does, skip the other tests)

3. Connect black/white to ground. Connect one side of the test light to battery (+), the other side to the green wire -> the test light should light up

4. Remove the tacho connector from the tacho and repeat 3 -> the test light should not light up

 

If 3. & 4. are positive, you have identified the tacho wiring

A friend just dropped off his Fluke DVM. Yes...he is a good friend lol.

I'll see if I can take a break from the carbs long enough to check this out. I'm rebuilding/refreshing the Webers.

[vantage]

A very good friend indeed, Fluke makes quite nice equipment!

[Mikez31ss]

Hi Mike,

 

the black/white wire connected to the coil with the black cable sleeve comes from the ignition key 'run' position, so the shorter black/white one with the female connector is most probably the one we are looking for!

 

Here is a quick and simple test: put the meter in resistance mode and connect one probe to the green/white wire (currently taped) and the other one to the short black/white with the female connector.

With the tacho connected you should see 0-2 Ohm. If you now disconnect the tacho connector behind the dashboard, you should see infinite (e.g. no) resistance.

 

If thats the case you have identified both wires coming from the tacho loop! Let me know how this works out, then we can continue to wire up the tach.

The meter displays OL.

[vantage]

O.L means the wires are not connected (infinitive resistance). Ok, now we need to check which of the two wire is not connected through the tach loop.

 

Please disconnect the tacho connector from the tacho. The tacho connector has a green, green/white, black, and black/white wire.

 

1. Measure the resistance by holding one probe to the (previously taped) green/white wire in the engine room and the other one to the tacho connector pin connected to the green/white wire. If you don't see O.L, then this is the correct green wire to connect to +12V from the ignition key.
    
   
2. Repeat procedure for the black/white wire by holding one probe to the black/white wire with the female connector and the other one to the tacho connector pin with the black/white. If you don't see O.L, then this is the correct green wire to connect to the coil's (+) terminal.
   

 

Good luck,

Adrian

[Mikez31ss]

O.L means the wires are not connected (infinitive resistance). Ok, now we need to check which of the two wire is not connected through the tach loop.

 

Please disconnect the tacho connector from the tacho. The tacho connector has a green, green/white, black, and black/white wire.

 

1. Measure the resistance by holding one probe to the (previously taped) green/white wire in the engine room and the other one to the tacho connector pin connected to the green/white wire. If you don't see O.L, then this is the correct green wire to connect to +12V from the ignition key.
    
   
2. Repeat procedure for the black/white wire by holding one probe to the black/white wire with the female connector and the other one to the tacho connector pin with the black/white. If you don't see O.L, then this is the correct green wire to connect to the coil's (+) terminal.
   

 

Good luck,

Adrian

Oops, the tach wasn't plugged in. There is .2 between the g/w and b/w in the engine bay. Also .2 between the g/w in the engine bay and g/w at the harness connector.

[vantage]

Ok, you have identified the two missing wires for the tacho setup.

 

Remove the wire currently supplying +12 Volt to the coil (+) terminal and connect it to the black/white wire with the female connector instead.

Connect the (previously taped) green/white wire to coil (+) and your tacho should be active again! (if its plugged in )

 

Good luck,

Adrian

[Mikez31ss]

Ok, you have identified the two missing wires for the tacho setup.

 

Remove the wire currently supplying +12 Volt to the coil (+) terminal and connect it to the black/white wire with the female connector instead.

Connect the (previously taped) green/white wire to coil (+) and your tacho should be active again! (if its plugged in )

 

Good luck,

Adrian

Let me make sure I have this right:

If I connect the two b/w wires together, the gr/w wire is then going to have 12v and supply power to the coil? And everything else remains as is?

You're worrying me here Adrian...it took a long time to get it running

I can't do anything yet. I rebuilt the carbs and two of the auxiliary venturi's were melted. I'm waiting for replacements before reinstalling the carbs. Then I need to see if the car still starts and see if I can get the carbs adjusted correctly.

[vantage]

Exactly, you put the tacho pickup loop inbetween the b/w wire supplying +12V and the coil (+) by doing this. The tach should work then (pressing thumbs).

 

Good luck with the carbs!

[Mikez31ss]

Thanks...I'll need luck with adjusting the carbs

I'll let you know what happens with the tach.

[vantage]

Some pics of the fancy new mount when it comes in are requested.

 

Took +4 weeks but i learned how to do technical drawings on the way... cnc machined out of a single aluminium billet, should be sturdy enough for things to come.

Height is exactly as the original distributor including cap, so might look original enough to not draw attention to the conversion

 

[Mikez31ss]

Looks very impressive. I'm pretty sure that is going to draw some attention lol.

What's inside the aluminum besides the obvious?