z31 ecu swap - no spark

[Blobber]

Guys, I have a problem and I'm out of ideas. I attached coil and power transistor to the ecu(ecu is from 86 300zx). I also removed the old wires coming to the coil.

 

This how I attached the coil and power transistor to ECU:

 

- coil + terminal to pin 34 and 12v source from the ignition switch.

- coil - terminal goes to pin 3 and B/W wire in power transistor.

- Blue wire from the power transistor goes to pin 5.

- black wire from power transistor goes to the body.

 

Is this right or wrong? I have also tried to change b/w wire and blue with each other without any luck.

 

ECU is showing three malfunctioning codes: 23(throttle position switch), 24(neutral/park switch) and 31(A/C?). Correct me if I'm wrong, but I think that these codes shouldn't prevent the engine start?

 

CAS is inside the distributor. I also don't have injector pulse. I have checked the connections twice. I also checked voltages from pins 34, 5 and 3, and I found out that pin 5 is only millivolts.

 

 

I think that I'm missing a 12v feed, but I' not sure which one. Is anybody able to tell me which pins need to have 12v feed. I have been told that there should be four.

Edited June 6, 2010 by Blobber

[LuvZBoost]

old thread... I know, but did you ever get a resolution? My 77, l28et w/z31 electronics is doing the same thing. I haven't ruled out the possibility of a bad ecu, but dont want to throw parts at it for no reason. 

[cgsheen]

Well, don't follow the above wiring scheme if you're using the stock 280ZXT coil/ignitor - it's wrong for that... 

Using a Z31 coil/ignitor (yes, you can) - it's probably wired like my M30 coil/ignitor, but you'll need the Z31 circuit diagram.

 

On the stock 280ZXT coil/ignitor:

- B/W comes from ignition switch - +12V at IGN ON - to top of "T" connector on ignitor. 

- B/W out of ignitor goes to "+" terminal on coil.

- Y/W comes from ECU pin 5 (through connector "3" (plug 3) near ECU on the stock 280ZXT harness) to leg of "T" connector on ignitor.  (Y/W from ECU pin 5 is "signal to fire" from ECU)

- L (blue) from ignitor goes to "-" terminal on coil AND back to provide Tach signal (through resistor to Tach)

  (L (blue) from ignitor is amplified "signal to fire" from the ignitor to the coil)

- Ignitor is grounded through the coil mounting bracket to the body.

 

- If there's a Black wire coming out of the ignition harness (wiring harness to coil/ignitor) with a female bullet connector, it's probably for the condenser, IF IT IS it's HOT - it'll be coming from the B/W inside the harness.  There has to be a condenser between it and ground or N/C.  (Easy to test if it's a GND or for the condenser connection: If it reads +12V (battery voltage) at IGN ON, it's for the condenser.)  Stock, it goes to a GND spade on the distributor (through the condenser) to help eliminate electrical noise that could interfere with the ECCS.