81 turbo swap question
 

hey guys,

I know I should have no questions when it comes to swapping a turbo motor into an S30 chassis since i have done it 3 times now but I'm doing a 4th and this time its my first 81. After wiring in the harness I realized other than the ECU and dropping resistors and ever so slight changes in the non ecu plugs on the harness its pretty much the same thing. I actually didn't even realize it was an 81 and just wired from memory then I was like oh crap this is an 81 popped out the write up for it and saw I only had to add one extra constant power and instead of having a start" signal I use a switched power" signal in place. Otherwise the exact same thing. Now here is my problem. The ecu I got sent with it didnt power up. LED never lit up. Said ok well ECU is possibly burnt out. Got another one sent to me... same problem. So now I'm going over my grounds and go hmmmm.... So i grab my 82-83 ecu plug it in, it powers on. Now, I didn't hunt down the exact differences in the harness years but would you all make the same assumption I am, that if I can power on an 82-83 ECU off an 81 harness wired as per the write-up on hybridz

aka: A quick FI and ignition 280zxt to S30 turbo swap guide - HybridZ


that I yet again have another crap ECU or is there some 81 turbo trick I'm oblivious to... I'm getting a bit frustrated haha.

the only trick my 81 turbo ECU did was randomly shut off on the highway had to unplug it and plug it back in to start the car. id say ur better off with the 82 ECU if its workin

How about an '83? Eric I have an '83 turbo ECU sitting in my garage.

Wish it were that easy. We'd have to o swap to a 83-83 turbo harness and dizzy to use tgat ecu

I've got a 89 z31T harness, ECU, MAF, coil, PTU and CAS for $210 plus shipping if your interested.

Thanks hoov. But this actually is not my project I'm doing this swap for mike and have everything done except getting the car to run due to the lack of powering up of the ecu. And I've never done the z31 swap so I wouldn't make mikes car my guinea pig. Ok folks maybe my question isn't concise enough. Assuming the swap I posted is 100% correct and I did the wiring correct. But the 81 turbo ecu's led won't come on when I turn the ignition on yet when I plug an 82-83 turbo ecu in and its led does light up would that presumably mean my wiring is correct and i have two shit 81 ecu's or is there something I could possibly be overlooking.

I'd pull them apart and check for internal damage then with power to the ECU start doing checks with the multimeter.

no one?

n what would I start sticking the multimeter to. I can't find any test methods n comparing wiring diagrams was hopeless

Where did you get this info? Link?

I compared the 81T ecu schematic to the 83T, and THE ONLY differences are:
-ECU pin#6 = Fuel Pump Control Module (81T doesn't have it, 82-83T does)
-ECU pin#114 = +12V unswitched power (81T doesn't have it, 82-83T does)

my info is from the first link i posted. sounds like i got another bum ecu then

The only difference would be that the 81T ecu sends a high impedance injector signal thus needing the dropping resistors vs 82-83T ecu already programmed for low impedance. If the 82-83T ecu lights up, I would just make jumpers to delete the drop resistors and plug in the 82-83T ecu.

the cas signals aren't different?

Yer different! :58:

Nope... Cas signals and wiring are exactly the same-oh. Even the plug is the same between the crank and dizzy CAS (read your link again... :D).

I knew the plug was the same. just figured since one is magnetic signal the other optical they would have different outputs. I see that's not true. I do see there are two turbo afm's though so any idea if there's a difference in those. or is it just jumper n done.

Just do it already! :106:

What's the status yo?

how would one use an 82-83 EFI harness with an 81tECU? The 82-83 harness has a plug for the dropping resistors and the 81t doesnt. Can you wire in resistors or do you have to an 81?

^^^ Moved to Snw's thread. Read this thread... it will answer your question. :023:

haha awesome! Where would i put the jumpers? In the ECU?

The green light will come out when you rev the car up to 2000 for a minute or so,,,then the light will turn on or blinks to give you a signal that the ECU is good!!

81 harness has the dropping resistor in the harness like 1.5 ft down the line from the ecu. I found the 81 cas covered in paint the ecu would never power and the jumper idea was so so. So instead I got an 82 harness dizzy oil pump shaft and ecu and then the motor seized. Pulled it apart did a full rebuild found a washer in 4 pieces in cylinder 2 causing the engine to jam. Put back in runs perfect but turbo won't create any boost.