z31 injection on l28

[Guest 240zturbo]

I was wonderinr if any one had info on using the complete injection system from a z31 on a l28. I have a 240z with a l28 that I would like to turbo and install better more capable electronics. I have seen all the posts on converting a 280zx turbo to z31 ecu, but since I'm starting from scratch why not use the whole ecu, wiring harness, maf etc from a z31? any help please.....

[GrayZee]

It can be done, the biggest challenge is the crank angle sensor. You would need to get a distributor from a 82 or 83 turbo engine, you would also need the oil pump shaft to go with it. I am working on a way to adapt a z31 distributor directly to a n/a L block. Once I've built one that works well I will start selling them. I am also selling wiring harnesses for that application too.

[Guest 240zturbo]

would I need to change the wheel in the dist. to the z31 wheel? and whats the reason for this?

[GrayZee]

Either way you need a z31 crank trigger wheel. The z31 distributor obviously already has one, but if you use a 82/83 turbo distributor then you need to take out the S130 trigger wheel and replace it with a z31 wheel. (the slits in the wheel are different) It fits right in a 82/83 dizzy. Or I can put it another way.

 

To run a z31 CAS on a n/a engine you would need the following parts:

 

1. 82/83 280zx turbo distributor

2. 82/82 280zx turbo distributor/oil pump driveshaft

3. a Vg30 CAS wheel

 

OR

1. z31 distributor (84-89)

2. adapter kit (which I plan on selling soon)

 

Assuming you had all those parts then you would still need a modified 280zxt injection harness. A z31 harness could be used as well but would require more work to fit the L28.

[Sean73]

I am running 88 Z31 EFI. almost everything is from the Z31, including the wiring harness, ECU, and MAF. I use the ZXT distributor with the Z31 CAS wheel installed in it. I am also using the Z31 ignitor and a generic aftermarket coil.

 

I mounted the ECU on the driver side kick panel, and trimmed the Z31 wiring harness to fit the L6 engine. I pretty much took apart the whole Z31 harness, and deleted the items that I didn't need. Having a wiring diagram helps.

 

The advantage of using the Z31 harness is that they are newer, and in mostly better condition at the junkyards. Also, since the wires are extra long, you will only need to cut them once, and install new connectors.

 

I made 232 HP at 10 psi on this setup. Will shoot for more power with an injector upgrade and ECU re-program. The 88-89 Z31 efi is the better choice over the earlier Z31, because they are relatively easy to re-program with an EPROM burner.

[twistex]

Instead of starting a new thread I thought I would bring this one back from the dead.

 

You all may know me from putting a 3.2 in my 240sx.. yes yes yes I'm already hating the 45mm side drafts on it. hmm do I waist my time with the fuel injection ? Or do I keep letting my girlfriend tell me my 3.2 is a POS because of my poorly tuned side drafts. I try to tell her they bog but thats because I'm going for top end. Shes use to EFI and well yes.. I'm use to efi since I spoiled myself with ka24de and e injected datsun 510's and ls1 powered 240sx's. I really would like to keep this 3.2 in my car because I don't want to let it sit in my shop and not get any use. I will later swap this into a 79 2dr 810.

 

Anyways lets get back on track here. Today I went to the yard and got myself a 1987 N/A Z31 Engine harness, ecu, maf, tps, o2 sensor, coil, cas wheel, injectors. I also have 280zxt dist and oil pump shaft. My plan is to rewire the z31 harness to adapt it to fit my l-series with a efi non egr manifold i have with ka 60mm throttle body. From the looks of the z31 harness it gets its power and has relays for efi right next to the battery tray on the z31. Does anyone have any input or doubt that this will not work ? I figured because my motor is a 3.2 that a z31 setup would get me close enough to drive around for a bit until I could tune ecu and upgrade maf and all that. I'm sure the 280zxt harness would have been a better option! I cant seem to find any that haven't been cut or destroyed. I know this may not give me the ultimate power and all that I just want to get the motor running nice and smooth and figure things out later. thanks.

[zcarnut]

.... Does anyone have any input or doubt that this will not work?

 

Sorry for the late reply, but I just noticed your recent post.

 

On my 1979 Datsun 810 (two-door hardtop) I used the ECU, the mass air flow sensor (the “hot-wire” type), the injectors, the O2 sensor and the fuel injection wiring harness (that was cut up to fit) from a 1987 NA (non-turbo) Z31. I also swapped out the 48mm diameter 810 throttle body with the 60mm 240SX one, swapped the intake manifold with the non-egr N42 one and used one of the aftermarket Z car fuel rails. I left the cable linkage on the 240SX throttle body and ran a throttle cable to my accelerator pedal. This also made adapting the cruise control easier.

 

For the trigger signal I used a 280ZX turbo distributor re-fitted with the Z31 optical trigger wheel. The ZX turbo distributor requires using its own unique oil pump driveshaft.

 

I retained the stock 810 electric fuel pump, but because the Z31 fuel pump is driven from both of its wiring leads, I designed an “interface circuit” to power the 810 fuel pump without having to re-wire it.

 

The Z31 injectors I got were the “high impedance” type, so I got rid of the stock injector dropping resistors. The Z31 uses an O2 sensor to help adjust the mixture which I had to add to the exhaust head pipe of the 810. I used the 810’s cruise control sensor as the “speed sensor” for the Z31 ECU. If you don’t then the hot-wire “burn-off” (cleaning) function will not work. I mounted the Z31 ECU where the 810 was (driver’s side kick panel). For the ignition circuit I used a 280ZX coil and ignitor box but you can also use the Z31 ignition items.

 

I first tried to mount the Z31 mass-air flow sensor between the throttle body and the 810 air-box, but I discovered that the later Maxima mass-air flow sensor could be made to bolt to the side of the 810 air box. At first I was going to transfer the “guts” of the Z31 air mass sensor to the Maxima one, but I decided to try the Maxima one “as is” and it seemed to work just fine. I eventually swapped out my 810 air box to the 1981-84 Maxima diesel air box which has more volume.

 

The only reason I went this route was the fact that I had obtained a Z31 parts cars for very little cost. The L28 in the 810 has been stroked and bored out to 3 liters, so the Z31 fuel map is close enough. During the swap I made notes and diagrams that I kept in a notebook, but I have not been able to locate it after I moved to Huntsville last year. I’ll keep looking for it.

[Kennysgreen280zt]

During the swap I made notes and diagrams that I kept in a notebook, but I have not been able to locate it after I moved to Huntsville last year. I’ll keep looking for it.

 

That would be awesome. It sounds like a few of us are in the midst of doing this setup.