The world's first Z31 na ECU swap
 

I've done it. The car runs, fuel pump works, ignition timing is off, but I have to re-pig the oil pump shaft. Will do a writeup when time permits. any questions just ask. I used all the stuff from a 85 NA with digital dash. I recommend using the z31 harness even if you are doing a turbo swap because then you can use all the ECU's functions, fuel pres. control, EGR control, easier integration of 280zx fuel pump, etc. Plus, it gives you an opportunity to make your EFI harness super clean with all new connectors and loom. Right now, the fuel pump stays on whenver the ignition is on, I think I got a wire wrong on the fuelpump relay, but it works. I will drive the hell out of this thing tomorrow with the wideband on it and see if its better than the flappy door and tick tock wheel setup.

Im such a genius.

Congrats on the swap! I'm sure this will help many people.

i knew it could be done, i actually though about it myself since of how easy it would be after doing the turbo swap. but im poor. lol. yeah hope you took pics for a writeup. now though, how does it run?

exellent, im waiting to hear the other good news!! i always figured id use the whole harness, i just like to do it right. did you use all the sensors too, or are some 280 sensors good for the job. ill wait for the writeup before asking much more.

If it's anything like the z31 conversion on the turbo's I'd think most of the sensors should all connect right into the harness. I know as far as the N/A goes most of the sensors all shared the same connection as the turbo cars, that's why they'd swap over so easily, just the connection was different at the ECU.

jmmorriso: my fuel pump does the same thing, I followed the instructions as I was supposed to and mine stays on as well. Instead of doing the 2-3 second prime.

Awesome bro! Pics and write up! Do it! NOW! :D

The 85 NA ecu apparently doesn't use the VSS for the MAF burnoff cycle, but the turbo does. It also doesnt use the boost sensor or the TP sensor, just the switch. If I had it to do over again I would use a 87-89 turbo setup to get the rest of these sensors in play and be able to run nistune. the cyl head temp is the same and the early z31 O2s goes in place of the S130 piece.

sweet, then i just gotta find myself a beater 300zx to grab all the junk off of. how much did all the stuff cost you, so i dont get ripped off. i take it the writeup will include a parts list? its prolly simple, but for the dunb ones you know :)

well done, cant wait to see the write up

you still havent told us how she runs!!!! lol.

So far, she runs like a raped ape. I have a little hesitation from idle when I mash the go pedal, but I haven't checked the timing when fully warmed up. I may need to calibrate the MAF, but will have to run the self diagnostics to find out for sure.

whats a raped ape? that could be good or bad. lol.....

advance the timing till it hurts!

Running like a raped ape is good for a car, not for apes. Ive got the timing at about 40deg total advance. I dont know how much more the ECU plays with it, I'd have to get a romulator and all that stuff next to find out. the stumble is still there from idle, but its not as bad now that I have calibrated the MAF, reset the TPS and upped the idle speed. I think I spent about 150 USD on the ECU, harness, misc sensors and pigtails. I bought a rebuilt dizz for about 200, new oil pump driveshaft for another 100 shippped from Courtesy, and all the solder, shrinkwrap and zipties were already in stock at my house. I guess I could start on the writeup tonight...

How do you calibrate the MAF?

Given the gas mileage and performance improvement, this write-up is sure to be a sticky... wait for it... wait for it...

The MAF has a potentiometer on it just like the AFM, but this one trims the airflow signal throughout its range. 120 on the freeway doesnt seem to be a problem now, but the chassis/ tires beg to differ. I have to double check the car's speedo against the GPS in my phone, but she was turnin' a little over 4 grand and according to my math that's 120.

The writeup:

1. I assume no liability for any problems stemming from this.
2. You're on your own passing smog.
3. Get a NA z31 harness, CAS Wheel, coil, Ignition module, fuel pressure solenoid and EGR solenoid. Get the boost sensor and vehicle speed sensor as well. Get anything else connected to the harness including the connector the goes to the chassis harness. It depends on the year whether you will need these last two or not. Dont forget to get a FSM for the year Z31 you just stripped.
4. Get a s130 turbo distributor and oil pump driveshaft. The shaft is available from Courtesy part no. p8000-15040 they call it a spindle.
5. swap dizz. and shaft. at TDC the flat edge of the shaft should point at 11:30, or just to the right of the upper hold down bolt hole. It's a big help to have a helper for this.
6. Determine if you will need to use dropping resistors or not. If you do, you're on your own.
7.Spend hours pouring over diagrams. You've got to run wires from the right side of the engine compartment to the chassis harness connector on the ECU harness You, ve got to re use or re make the ignition wiring in the left fender. I ran new fuel pump wires and used a seperate relay so I didnt have to hack the stock wiring should I ever have to put the old harness back in.
8. Mounting the MAF is up to you. I made a new intake tube from an old intercooler pipe and put the bungs for the air regulator and idle valve in it. I then used some silicone couplers to join it all together. Don't do this until you mount the dizz, cuz its a lot bigger than the stocker.
9. I used the z31 solenoid valves to control the FPR and EGR valves, thus eliminating all those old vacuum valves and hoses.
10. the VSS on analog gauges cars is just a grounding switch apparently, so I think you can use the setup in the 280 speedo provided that your car had cruise control. This is just speculation however.
11. I know Im missing a lot of stuff, but this should get you started. I work on worse crap than this for a living (garbage trucks) so a 1'' diameter bundle of wires and four or five different wiring diagrams wont slow me down much, specially when its not covered in old diapers and broken glass. Feel free to ask questions and please gain a thorough understanding of whats going on with the ECCS before you start cutting.

Awesome! How bout some pics?

I think it's amazing, that it seems like the 280ZX keeps seeing the most innovation brought to it out of the Zs. Sure it may not be anything spectacular, but finding out new things like how the Z31 suspension can be swapped, swapping in Z31 Setup into the 280ZXT and now N/A.

Again, amazing work on bringing something new to the 280ZX.

i think i am going to do a z31 ECU swap into my z32!

You realize I'm coming over to your house this weekend to see this right? :D

im still confused. does it run good? or bad? lol... why does everyone beat around the bush on this question!?!?!

It runs good. He said it's running like a raped ape, which means real good.