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HybridZ

In Progress: 75Z getting 81ZX Turbo motor.


EverRude

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Wiring is not that bad. Lay out the entire '81 engine bay harness on the ground, and lay out the entire '75 engine bay harness on the ground. Arrange them as they would sit in the car, and compare the two. Check to make sure all the plugs on the '81 are there, intact, and clean the contacts. Get the harness in the car, and try to match up things like oil pressure sender wires, alt wires, coil wires, gauge wiring, things that you know, and then work on things you don't know, like injector wiring, the computer, temp sensors (all three of them), oxygen sensor, etc. Work it out section by section, use the '81 as a reference for mounting the computer, be methodical. You'll get it.

 

Like the others are saying, don't give up now, it will be so worth it in the end.

 

I could try. But I never unplugged anything from the turbo harness that was attached to the motor. Seemed to me to be easier leaving as much as possible plugged in. That way anything disconnected was the only things I would need to sort out.

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Ok. I'll keep trying. Atleast I managed to get it cranking again. I had disconnected part of the Z harness and hadn't pluged it in yet. I'm sure most of the rest of my problems are simple overlooked items. Aside from the ECU and AFR mounting mods. I'll keep working but I'm still far less than happy about my progress. I appreciate you guys encouraging me to keep at it. Still wish it was a carb'd motor tho.

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You've let an absurdly large amount of data seep into your brain regarding this issue in recent weeks. It is simple data, but there has been a FLOOD of it. Simple or not, it takes a bit for your brain to really digest it all well enough to come back and actually work with it all as functioning knowledge and not abstract knowledge. Simple it is, yet hair-splittingly specific and detailed.

 

Take a break, take a few days off and help the wifey, ignore the car for a little bit, and come back.

 

Its a very very common thing in my experience, and all the perseverance in the world can be to no avail if you don't take that all-important step back before you persevere.

 

Alternately, I will talk to my old man and see if we can put together a carb setup :D (only half serious, don't hang any plans on this tongue-in-cheek post unless I say otherwise later)

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I appreciate the advice and support Daeron. I'm going to make myself overcome this challenge. Mounting the AFR is going to be a pain. Especially with the engine installed. I'll get it figured out though.

 

I like fabricating custom stuff so atleast that part will be fun. Unfortunately it's not going to be as simple as welding up a a new bracket. It means cutting my radiator support and wheelwell. Still that stuff is fun. Then I'll get back to the wiring crap I hate.

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Post some pics too! Hang in there, I think you will be quite happy once you get it going. Everything I've read on the swap seems very straight forward. If you get stuck just post a few questions, there should be a ton of people who will chime in and help out.

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That sucks to hear. the Magic Smoke is never a good sign. Like others have said, just step back a bit, and work on something else. Hell, I've got 10-12 months of bodywork done, and another 10 months worth to go before I can even think about the motor, but sometimes I just have to let the bodywork go and play with engine parts for a while. Hammers and Bondo gets easier after that.

 

these cars aren't like the mustangs and camaros. You've really gotta work on them to get it running good, but by god, i'd never trade it for anything.

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The smoking wire was a ground when trying to turn it over. Not a real issue but certainly shows I have it all wrong. I'm going to clean it up and reassemble everything not put together (driveshaft, hood...etc) and sell it. Hopefully I'll get most of my money back.

 

Expect to see it in the For Sale section in a few days. 1975 280z L28ET 5 speed (not T5). Does not run. Needs wiring. Solid Frame rails, quarters and rockers, but rusty fenders, spare tire well, rear hatch ledge, and passenger floor. New clutch and slave cylinder. Clean title.

 

Lesson learned, stay away from EFI. This is a real heartbreaker. S30 is a dreamcar for me and I failed to make it work.

 

Thanks for your support guys. I'm sure I'll be back if and when I find a 240.

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Sigh...

 

I'm still trying. Still frying wires too. Going to try to take it one step at a time. First get it cranking. Right now it attempts to crank and grounds start smoking. Posting a question in the electrical section about it.

 

Then I'll try to get fuel working. And finally spark.

 

First the cranking tho and wiring repairs to the fried ground wires.

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You'll make it man. trust me, once you get that L28ET running, get the car derusted and painted up in your favorite color, and adjust the driver's seat to your most comfortable position, you'll never be the same.

 

You'll be...a HybridZ'er. No finer automotive achievement in the world, in my opinion.

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i used the 77 wiring harness a and computer on my turbo swap and it works perfectly other than a little rich around 3/4 throttle and up i just adjusted the 77 afm spring a little tighter to make upfor the turbo sucking the afm wide open too soon.i wouldnt trade my 77 turbo car for anything. i built a trubo waste gate controllerusing a standard pressure regulator set at 10 psi and used thestock blow off valve to make sure it doest overboost.i had to change out the oil pump drive and distributer to use the 77 distributer. i tried the using the 81 turbo wiring and computer but this way was so much simpler

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  • 3 weeks later...

Well I did get the car to crank without smoking wires. Turns out there was a ground to the main harness I hadn't connected when I swapped the motor. The old wire was Red and I didn't realize it was a ground until I traced the pinouts at the ECU connector.

 

I get spark but only when I run a hot from the battery to the + post on the coil. Means the coil and distrubutor are fine. There's 12v to the ignitor with the switch in "on" so it could be the ignitor isn't properly grounded or it's bad. Injectors aren't firing.

 

So even if I manage to get spark properly I still have to sort out the injectors. It's really too much for me. Too many thinks it could be and my troubleshooting skills are far too haphazard and impatient to make it work. If I ever manage to get it to run it'll be pure luck.

 

I tried. I'm not upset that I failed to make this work. In fact I'm proud I swapped the motor all by myself. I usually have help for that stuff. As long as I have the car I'll keep playing with it but I won't spend any money. I've listed it for sale but maybe I'll get it running before that happens.

 

I appreciate everyone's support. I feel like I let you down more than myself. Sorry.

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Well I did get the car to crank without smoking wires. Turns out there was a ground to the main harness I hadn't connected when I swapped the motor. The old wire was Red and I didn't realize it was a ground until I traced the pinouts at the ECU connector.

 

I get spark but only when I run a hot from the battery to the + post on the coil. Means the coil and distrubutor are fine. There's 12v to the ignitor with the switch in "on" so it could be the ignitor isn't properly grounded or it's bad. Injectors aren't firing.

 

So even if I manage to get spark properly I still have to sort out the injectors. It's really too much for me. Too many thinks it could be and my troubleshooting skills are far too haphazard and impatient to make it work. If I ever manage to get it to run it'll be pure luck.

 

 

I tried. I'm not upset that I failed to make this work. In fact I'm proud I swapped the motor all by myself. I usually have help for that stuff. As long as I have the car I'll keep playing with it but I won't spend any money. I've listed it for sale but maybe I'll get it running before that happens.

 

I appreciate everyone's support. I feel like I let you down more than myself. Sorry.

dont give up you are just doing it a little hardr than i did mine using the 77 wiring harness and the 77 dist and dist drive and it works good

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I'm giving up but I'm not. Listed it for sale here on the boards and my local craigslist. I'll still keep working on it but if someone offers to bail me out for the cash I have in it i'll take it. I just refuse to spend any more money on it till it runs. However I manage it.

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When I swapped the l28et into my 260z, I had the problem of no spark, the problem was due to powering the efi relay with an acc power instead of "on" power.

 

If you wire the relay with an acc power it will cut power while cranking.

 

As for the injectors, did you pull the dropping resistor with the harness?

 

The dropping resistor are in series with your injectors, without them the injectors won't fire.

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  • 2 weeks later...

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