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L28ET Z31 ECU/MAF build thread


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Well, here goes. I suppose an introduction is due before diving into the oil and grime.

 

My name is Andrew, I'm nineteen and a community college student, saving funds to start an EE degree program at University of Texas at Austin. I own and drove a 1978 280z, orange with black stripe, and mixed history. I picked up this car through datsun trader, then found it for cheaper on eBay. Primarily interested in it for the lack of rust, I bought it and shipped it home, well aware engine longevity could be a problem. Then again, these engines were supposedly indestructible, or so I thought. 

 

About two months ago I was driving back home from Springfield, MO, during a blizzard. High winds, bad aerodynamics, and poor traction had my eyes glued to the road, and I failed to keep my eye on the other gauges in my dashboard. Apparently a piece of road debris cut into my oil pan, and I didn't even notice it. Soon, that starved engine grinding noise came from my engine bay, and the car died as I clutched in. Long story short, it took several friends, two tows, and about $270 to get my car home. Then came the decision of finding another stock NA block or going turbo. I would have preferred to find a full turbo parts car, but after searching local listings on multiple sites, finding someone selling it cheap wasn't going to be a simple matter. Then, about five hours away, or $70 drive with my mother's Buick, I found a JDM turbo block ordered a good ten years ago sitting in someone's garage, paperwork and everything included. Picked it up for $150, stuffed it into the back seat, and buckled it in. vwleE77.jpg (Damn, that sucker was heavy, even with three guys trying to stuff it into my mother's car)

 

After that was removing the old engine. emeQoCJ.jpg Fairly straightforward. Then drop the new one it. kzILrPs.jpg

Too bad I didn't notice I was dropping it in with the motor mounts reversed. Took me a while to figure out why my transmission was tilted. :oops:

I went on a parts hunt, along with diving heavily into the torrent of information on here. It feels nice to say I actually understand how my car was put together now.

 

Basically, here's my parts list:

Stock turbo system

DIY'd MBC - not run yet

1st Gen DSM BOV - I actually welded this to the before-turbo intake pipe. I'm an idiot, I know. But I guess I'll leave it off until I find an IC to mount as well.

81 block, 82 harness/dizzy with 85 chopper wheel, 87 ecu, 85 MAF.

I have a new fuel pump, but not even Bosch can give me information regarding its flow rate, so that puts a stick in my installing it.

z31 ignition coil and power transistor

still running the original transmission, no problems with it. Redline mt-90 is the best stuff ever. 

4.11 LSD R200 diffy

370cc ford brown top injectors

 

Most of the fun came in the wiring, where the original owner took a few glances at the wiring diagram, screamed "F*** this S***" and did his own thing. That was fun. Fried two coils before getting it right. I guess that means I should never assume anything. Ever. Not with this car. Well, I finished all the wiring, and after all is said and done... 

 

 

 

So there's a few timing issues, and I failed to notice there was a plastic plug holding in my oil at the oil filter sandwich. Oil went everywhere. Yeah, not a single place in town could make fittings, (NAPA just opened, and Autozone and O'reilly were stumped. The plumbing shop couldn't help either) so I had to jury rig something with hydraulic lines, JB weld, teflon tape, and ultra black permatex. Qo492zb.jpg

 

That's a shot of how messy my shop is. I'm moving pretty quickly with this considering how much time I've had allotted for it. I just finished finals in college so this past week I finally got the engine running. I'll always appreciate a few comments. The main one is regarding installing the distributor shaft. I've heard to install it at 11:25 when at #1 TDC, but A, I had to find my own TDC with rope and a file, and B, I can't really find the picture in my FSM I downloaded. I'm fine with just a page number if you guys know which fsm has an install picture. I might be a bit off, so are there any tricks to optimizing timing without the marks? 

 

My power goals are about 280 hp at the wheel. I figured it'd be a nice tribute to the nomenclature of the s30 I drive. Maybe in the future I'll go crazy (after I have my degree and a bit more of an idea what I'm doing) for super high horsepower numbers, but right now a hair under 300 hp is fine with me. 

 

I'd like to thank awolfe for his wiring diagram. Saved my life. http://www.classiczcars.com/forums/misc-s30/44992-somewhat-color-wiring-diagram-1978-280zs-enjoy.html

 

I'd like to thank afshin for his guide to adapting the ECU http://forums.hybridz.org/topic/26230-z31300zx-ecumaf-to-280zxt-swap-guide/

 

I'd like to thank Tony D, NismoPick, and Bleach for the information they've provided on multiple occasions, and for making me laugh through this otherwise strenuous research phase. 

 

And I wish I could thank the rest of the OPs who created topics asking the same questions I had as I was doing this. 

 

Where are the wiring diagrams for the z31? I've been unable to find them anywhere. Color would make my eyes less... Crossed, as I follow the pinouts for the efi system. 

 

Edited by noelawinslow
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sounds awesome, with that power transistor on the coil, try and get the z31 version that allows you to mount the ground separate from the coil.

 

Fried two of them on accident, one by having it not grounded (s130 grounds through coil mounted on chassi and I had it off), and the other by wiring it backwards.

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