Z31 AFM/ECU Swap - 240z - NO SPARK

[Yoak]

GrommitZ,

 

Thanks for the reply....

 

I have swapped the Z31 Blaster Coil back into the car with some pictures attached....

 

 

The Original lines that were used with the coil are hooked up as they were when running L28 AFM....

 

RED hooked into B/W <+>

Blue into Y/W <->

(ON L28 ignition harness...used for original L28ET setup)

 

 

I know the blue wire in the center of the shot needs to be reconnected to the plug below, just didin't have a chance yet...

 

 

 

 

 

 

 

 

 

Pin 3 --> Connect it to the B/W on the harness of the coil..

 

Pin 5 --> connect it to the Blue wire on the coil harness <+>

 

PIN 34 --> Connect to original BRIGHT RED WIRE (PRE COIL)

 

Thanks again just want to clarrify before moving on

[GrommitZ]

Hi Yoak,

I see you have a the Z31 coil and powertransistor, but the wiring to them is different from the ones I have seen. In my case, the wires from the coil were much longer and merged into a larger wire harness branch. Also, the 1986 300zx wiring diagram I have only shows only one wire going from the powertransistor to the coil. It looks like two of your wires are going from the powertransistor to the coil. This implies to me that the current source to the positive terminal is being modulated in the vehicle('88 Z31?) you got the coil and powertransistor from.

 

I know from my own experience with hooking up the 300zx coil, that it works differently from the 280ZX coil. For one thing, my modified tach doesn't read any RPM's with the 300ZX coil. Because it looks like the 300ZX isn't getting a constant 12 volts, I would not reccomend using that coil with the way I wire the ignition(like the way the 280ZX Turbo ignition is wired).

 

I'll list steps of what I would do if I was in your situation.

 

1. Replace the 300ZX coil with your previous coil, but keep the powertransistor.

2. Connect Pin 34 (red in your pic) and the positive terminal of the coil to an ignition ON switched source. I can't tell which B/W wire you are using for your ignition ON switched source, but keep in mind that the B/W wire coming from the powertransistor in your pic is not for this purpose.

3. The B/W wire coming from the powertransistor in your pic should be hooked up to the negative terminal of your coil. Pin 3 and eventually your tach sensor wire should also be hooked up to the negative terminal. You will have to modify your tach before hooking the sensor wire up.

4. The blue wire with what looks like a faint white stripe (L/W), coming from the powertransistor should connect to pin 5. I believe you connected pin 5 Y/W to a blue wire and ran it out to the coil previously. It should instead connect to the L/W coming from the power transistor.

5. I'm guessing the wire above, with the eyelet, is the one coming from the condenser, which has another wire going to the distributor. If so, the eyelet should also be connected the positive terminal of the coil.

 

To summarize:

 

1. Replace 300ZX coil with your yellow coil.

2. Connect postive coil terminal to

 

 

[GrommitZ]

Whoops. I posted before completing my reply.

 

To summarize:

 

1. Replace 300ZX coil with your yellow coil.

2. Connect positive coil terminal to

a. Ignition ON switched source

b. Pin 34 of ECU

c. Condenser

3. Connect negative terminal to

a. Pin 3 of ECU(actually not required, but removes ecu error code

b. B/W wire of powertransistor

c. Tach sensor wire after tach modifications

4. Connect L/W(the faint white line in your pic) wire of powertransistor to pin 5 of ECU(Y/W which is blue in engine compartment), NOT to positive terminal of coil as you noted above.

5. I didn't see a pure black ground wire on the powertransistor in your pictures, but if you have one, ground it and make sure the powertransistor heatsink is grounded too.

 

Let me know if you have any other questions.