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Z31 AFM/ECU Swap - 240z - NO SPARK


Yoak

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Well I have been reading over the diagrams now for 2 days, and I have tried everything that I can think of to resolve the issue at hand.

 

Here is my setup

 

240 w/ L28ET Turbo swap

1983 - Engine & Harness

Z31 Coil

 

MAF was Wired in :)

ECU Z31 88 NA (Will be reprogrammed later)

-----------------------

 

I have followed the guide and I am connecting the ECU to the 83ZXT harness...

 

Car has no spark....

 

If I reconnect the 280ZXT ECU, I will get a spark.

 

I have added the additional pins as needed, connected metter to pins 34 & 3 and I am not getting a signal, hence no spark.

 

The Wires to the coil are hooked up to the harness as they were when I was running the Stock 280ZXT setup...., I have attempted to disconnect and wire to the ecu as well.

 

Do I need to modify the harness and move the pins that are causing it to fire on the 280ZX setup?

 

 

Anyone in the area want to help? :)

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Ok I installed the chopper wheel....

 

I checked the voltage from pins 34 3...when accs are on I am getting around 10-12 volts....engine turns over but still not starting....

 

ECU also has a green light coming on

 

I did not wire the FPR as noted in the instructions as this was done with the engine swap, pump is on and running as it should be.

 

With the old L28ET setup after cranking the engine you could hear the dist click for a few seconds...that is not the case with current setup...

 

Original Dist wires are wired as they were for swap, with the additional wires coming from the ecu as noted in the insturctions....

 

I am sure it is something simple at this point....Help!

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The only X factor I can see in this swap is that I am running a Z31 Blaster...

 

I mean the wiring is fairly straight forwared on this setup.

 

Hook up AFM, run additional lines to to coil +/-

 

Again if I hook the old ecu in I do get spark, and the dist makes a ticking noise for a few seconds...there is an obvious absence of that now

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OK, so I swapped in a normal blaster coil into the system.

 

I check voltage on the positive terminal to ground, 8-12 Volts (battery getting weak)

 

Power across the terminals is 0 with switched power on, and when cranking....

 

NO Idea what to do now...bad ecu?

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I have followed the guide and I am connecting the ECU to the 83ZXT harness...

 

Got dark on me tonight, my understanding, and correct me if im wrong was on the 83 Dist. there was no need to swap the chopper wheel.

 

I did not wire the FPR as noted in the instructions as this was done with the engine swap, pump is on and running as it should be.

 

With the old L28ET setup after cranking the engine you could hear the dist click for a few seconds...that is not the case with current setup...

 

Original Dist wires are wired as they were for swap, with the additional wires coming from the ecu as noted in the insturctions

 

Just reading thru your posts... it sounds like you DIDN'T follow the instructions very well. Tho the 88 na ecu is setup somewhat differently than the 84-86 turbo ecu (like in Afshin's sticky).

 

There are 2 main reasons an engine won't start:

 

-no fuel-

-no spark-

 

You've verified there is fuel getting to the combustion chamber? (are the sparkplugs wet w/ fuel?)

 

Have you verified spark? (pull off a wire & set it near a ground when cranking... look for spark)

 

If your battery is getting weak... hook up a battery charger. :D YAY!

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Alright! Here we go.

 

I am now using an 84 ECU Turbo.

I am now using a Standard Coil

 

 

I am gettting fuel at the plugs :icon14:

 

 

MAF

A: Y/Green -> Y/Black (30) --> ECU

B: BLACK --> Y/Red (31) --> ECU

C: Black/Brown Spots --> GROUND

D: Black/Brown Spots --> Black (26) --> ECU

E: Black/White --> SPLICED INTO Black/White

F: Y/Blue --> Yellow Red --> TO BE CONNECTED TO SWITCHED POWER LATER

 

2177873_59_full.jpg

 

 

2177873_60_full.jpg

 

 

2177873_61_full.jpg

 

 

2177873_62.jpg

 

 

 

2177873_63.jpg

 

 

2177873_64_full.jpg

 

 

 

2177873_65.jpg2177873_66.jpg2177873_68.jpg2177873_69.jpg

2177873_70.jpg

 

 

ECU

 

 

2177873_50_full.jpg

 

2177873_51_full.jpg

 

 

3 --> ECU --> WIRE TO NEGATIVE TERMINAL ON COIL

 

2177873_57_full.jpg

 

2177873_58_full.jpg

 

34--> ECU--> WIRE TO POSITIVE TERNMINAL ON COIL

 

 

23--> CUT & SPLICED INTO 15

NEXT POST

 

 

L28 Harness Hookups

 

2177873_48_full.jpg

Y/W --> RAN BLUE WIRE TO NEGATIVE ON COIL

 

 

2177873_49_full.jpg

B/W --> RAN RED WIRE TO POSITIVE ON COIL

 

NOTE This are the wires that ran the Coil on the L28ET Computer, and spliced into the same location as before

 

 

COIL

 

2177873_44.jpg2177873_47.jpg

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Your MAF wiring is fine... but the coil wiring seems a bit wierd.

 

-I installed a pin to ECU slot 3... turns out you don't need it. I have mine disconnected.

 

-New ECU pin 12... runs to MAF... connected?

 

-New ECU pin 34... run to + ignition source. I ran mine to the stock fuel pump controller black w/ white stripe wire.

 

-Did you swap pin 16 & 108 for the air regulator & fuel pump relay?

 

I think part of your problem is you are connecting pin 34 to the + coil... it's better to connect it to a different + source (makes trouble shooting easier).

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Alright I made some correction based on the last post.

 

 

Pin 34 is now going into Pin 36, and no longer to the coil.

 

Pin 3 was also removed.

 

 

Checked Voltage, Positive of Coil is @ 10-12 Volts, when grounded to the body of car.

 

 

NO Voltage is found when going from Positive to Negative On The Coil.

 

When Cranking there is no Voltage across the terminals

-------------------------

I did not rewire pin 16 & 108, as I am getting Fuel Pressure, my car was wierd different, so this wasn't an issue.

 

Also did not connect 12 as my car does not have a speed sensor (240Z w/ 28)

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Strange, I am getting voltage when switched on that pin.

 

Ill double check that pin number in the morning.

 

 

 

Maybe I misunderstood what you wanted me to do....

 

I took the wire I ran from 34->+ Coil and re ran it from 34 to a switched source...

 

34 TO PIN X (B/W)

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Hi Yoak,

 

You're missing a powertransistor for your coil. It allows the ecu to control the grounding of the negative coil terminal which causes the coil to fire. On the Z31 300ZX, it is a solid state transistor, mounted to a small shiny heatsink, a few inches away from for the 300ZX coil. It's less than 2 inches long and has 3 wires coming from it. If you have a 280ZX Turbo coil, the powertransistor is mounted on the coil's bracket. Note that the 2 powertransistors need to be wired differently.

 

In either case:

 

Ignition ON positive lead should connect to the positive coil terminal and pin 34 of the ECU.

 

Pin 3 should connect to the negative coil terminal(required for 300zx powertransistor).

 

Pin 5 (Y/W) connects to the powertransistor positive lead, which is a different color depending on which powertransistor you have. On the 280ZX Turbo, the powertransistor is prewired to the coil and has a 2 pin connector. One of these pins plugs to the B/W ignition ON wire. The other goes to pin 5 of the ecu. For the 300ZX powertransistor, Pin 5 Y/W connects to the blue wire coming from the powertransistor.

 

300ZX Z31 powertransistor B/W wire should connect to the negative coil terminal, which in turn connects to pin 3 of the ecu. The pure black wire should connect to ground.

 

Hope this helps. Also, it looks like your condensor is hooked up incorrectly. It should have one wire going to the distributor(correct) and the other going to ignition on. You have it connected to the coil negative terminal. You can just move it to the positive coil terminal.

 

Good Luck and I'll check to see how you're doing later.

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