Fuel Injection Wiring between Turbo and NA ECCSs

Wow. I never even noticed that difference in the wiring; thanks for the info! Though as far as I can see it really only changes the injector firing sequence? I'll try re-pinning one of my nistuned cars this weekend and see what kind of a difference is shown on the wideband. If I can ever get my laptop running again I'll post some logs.

On a side note I appreciate your active work on this. I've had so much going on in the last year that there has been almost no time left over for Z stuff. I know I need to update some of the information on the redz31.com website BADLY (havent touched most of it for 2+years) do you mind if I use your images/text?

confused!!

the 86+ ECUs have the same injector configurations as what? Do you mean all 86+ ECUs use the same configurations whether turbo or not? Or did you mean that they have the same configurations as the 84-85s?

Basically I'm trying to figure out if this is something I'd need to look into on my 1985 N/A engine and wiring harness that is running a 1987 N/A ECU.

That 86 diagram i have is the exact same as the 87-89. No changes, instead of posting up all the pictures, i posted 1 and saying they are the same.

Jason if you were asking about mine, go for it man!

http://www.tboz31.com/300ZX/Z31EFIHarne … wiring.htm

You mis-understood what I'm asking. Your first pic shows that pins 101, 102, 103, 104, 105, and 106 correspond to injectors 1,2,3,4,5,&6 respectively on an NA for 1985. Your second pic shows that on 1986+, those same pins correspond to injectors 1,3,5,2,4,6 respectively for an NA.

Here is my question: I had previously re-wired my injectors BACK TO FACTORY as shown on Jasons site. But then later I swapped in a 1987NA ECU for my 1985 one… so, according to your pictures, when I installed the 1987 ECU, I actually UNDID that and put them right back into the same firing groups that Nissan did when they changed the injector groupings when they performed the recall. Does this make sense??

So, in order to change my groups back to 1-2-3 and 4-5-6, I would need to redo it all over again. Currently, I should still be using groups 1-3-5 and 2-4-6 due to the difference in pinouts from the ECUs.

Or am I not understanding anything here at all? Somebody help set me straight!!

Actually on second thought, I now question the validity of those diagrams, at least for NAs..
Here's my reason (and I'm considering ONLY an NA car in this):

When Nissan rewired the injectors for ANY Z31, they grouped injectors 1,3,&5 to injector 3's leads, and they grouped 2,4,&6 to injector 4's leads.

Based on your diagrams, if it were a 1985 NA Z31, that means all injectors on the passenger side (1,3,&5) connect to pin 103, and all on the drivers side (2,4,&6) connect to pin 104. Also, if we look at your diagrams for 1986+, that means that Nissan would have wired injectors 1,3,&5 to pin 102, while injectors 2,4,&6 were wired to pin 105. All the other wires were simply cut and covered in tape and shrink tube.

The only problem with that is, it would be IMPOSSIBLE for any 1984 or 1985 NA Z31 to use a 1987 NA ECU because the leads going to injectors would have been cut due to the different pinouts, and none of the injectors would ever fire. (If 1987 truly drove injector 3 with pin 102, that lead was cut off and just tucked up not connected to anything, hence no injectors)

Well, that means that in either scenario, 1984-5 and 1987 MUST use the same pinouts and wiring.. if they didn't, those who haven't rewired back to factory wiring (undoing the injector campaign) would NOT be able to do the ECU swap which is relatively well known to work.

I was just trying to make things clear, as in get a picture of wiring out of ECU w/ color and a simple chart.

The Wiring diagrams came from 2 big companies. Mitchall on demand and Alldata pro. I printed out all the engine harness diagrams from alldata pro at school on paper to look at all the differences and then copied the diagrams off of ondemand5.com for the pictures you see.

I can't explain the campaign or the wiring differences. Just showing what i can.

I just swaped the actual injector clips to the proper injectors. Is it ok to do it this way? I think it fixed my rich problem but now i have a slight hesitation right after 3k rpm.

I put in a 87 T to a 88 NA is the wiring need to be changed ? If so were is this located? Im realy having trouble with the idle and it cuts of around 5psi 3500rpm on semi load. (T3 T4 intercooled pathfinder manifold,stock injectors and computer) . thanks

Yes, your wiring will need to be changed. The wiring is located at the connectors that plug into the ECCS. As far as what needs to be done, that information is written within this thread.