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Unilite Install Help 78 280Z


Jimzee78280

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Hello all, I am preparing to install a new Mallory Unilite distributor into my 1978 280Z. First off, if anyone has done this successfully and has photos please reply with them attached if possible. I have a few questions:

1) Like a previous post I read, I noticed that the #1 plug wire is not in the exact same position on the mallory cap as it is on the stock cap. The advice given was to go ahead and install, and simply rotate the distributor to align with the rotor. Did that work? Send photos if possible. If that did not work, please advise on how to resolve this.

2) How (exactly) do I run the red, green, & brown electrical wires from the new Mallory unit to the stock electrical wire locations, referring specifically to the connector bracket located on the driver's side inside fender? Again any photos?

3) Regarding the adjustment bracket received with the Mallory unit. Please send me photos of how this is installed onto the stock bracket.

 

Thanks for your help!

Jim

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This should help, generic instructions from the internet - http://prestoliteperformance.com/Portals/0/downloads/mallory/pdf/Mallory_Instructions_unilite_distributor_wiring_diagram_test_procedure_1214M_0000.pdf

 

Looks like the Unilite has an integral ignition module. So you should unplug the stock 1978 module one up under the passenger side dash by the fuse box, it won't be used anymore. The wires from your old distributor don't matter anymore, that connection you show just leads up to the old ignition module. Make sure to keep the blue wire from the coil (-) connected since it runs your tach and EFI system.

 

Looks like you might need to install a resistor between the coil (+) and the power line to save the Unilite electronics, according to the instructions. The 1978 doesn't come with one. This might not be best for spark energy though, I think that it will add required dwell time. Not very clear on these generic instructions.

 

As far as alignment of the Unilite compared to the old distributor, just make sure that the the rotor points to the same spark plug terminal in the distributor cap after the switch, then use a timing light to set timing.

 

Why are using a Unilite? It doesn't seem to offer much over the stock 1978 distributor and ignition module.

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The Mallory can be altered with the centrifugal weights somewhat easier than the Hitachi unit in there stock. Mine took a dump fairly quickly, and I've been Hitachi or distributorless since.

I was going to ask if the instructions came with the dizzy, it was a complete breeze when I did my swap back when this was basically the only alternative... Looks like the same instructions, too.

The wiring is exactly like most other aftermarket ignition triggers:

 

RED=12V Ignition on, Coil + (CURRENT LIMITED WITH RESISTOR on this unit-a weakpoint IMO)

GREEN= Coil -

BROWN= Block/Chassis Ground

 

That hasn't changed in 27 years...

Edited by Tony D
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Re the resistor recommendation - At the top of the first page Mallory (or Mr. Gasket) has a paragraph under the heading IMPORTANT. They even give a Mallory part number for the resistor and say that failure to use one will "eventually destroy the UNILITE ignition module." It does seem odd to design a performance ignition module that limits current to the coil. Who knows, it's probably better than the points system it was designed to replace, but not quite as tough as the electronics that came later. Maybe that's why yours took a dump?

 

I'm no expert, I just browsed through the instructions to see what was what, and that caught my eye. Seems like Hitachi and an HEI module would do the job, if you're not swapping the weights, which I would guess the OP is probably not planning to do.

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Mine was a mechanical failure, to this day I have never had any aftermarket optical pickup units I've installed fail.I have had one reflector-based system fail.

 

That puts me squarely in the optical trigger camp,

 

The caveat tells me the Unilite is a 6V component-the resistor limits current in the switching module NOT the coil, universal application over all years. Every other one I've installed either works off 12V, or has a special part number for 6V application.

 

For this reason, that would make two strikes AGAINST using the Unilite... Really, buying the advance kit is the only thing that is easy about this distributor.

 

Using a stock dizzy with a standard optical trigger to a MS triggering MS-n-S is the way I would do it now, the advance curve will fo things you only DREAMED it could do with weights and springs...

Edited by Tony D
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mallory offers a replacement e-spark module for those that is more durable and actually cheaper than the one that the old models come with. the old module was very sensetive and would leave you stranded. the new one can handle the voltage without resistor. i had to replace my module when i was trying to make it work with megasquirt. i felt it was more accurate than the reluctor style my 79 had stock

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I would HIGHLY recommend the spark module upgrade in that case!

 

The assumption on optical triggering is also correct. It will trigger on first light consistently, while a hall effect or reluctor magnet based system has to have a consistent rise to trigger point...and depending on RPM it doesn't. There are also RPM limitations on magnetic pickups which is why most are monuted on the flywheel and or crank pulley. The resolution afforded by the physical limitations of the triggering 'spike' to pass the coil pickup will loose resolution after about 4000 distributor RPMS and start having errant triggering issues.

 

In comparison, the STOCK NISSAN Z32 optical trigger showed absolutely rock solid triggering to 12,000 DISTRIBUTOR RPMS! (that's to 24,000 engine RPMS!!!)

 

Optical is really the way to go for consistent triggering in a distributor-sized package.

 

Magnets work fine on the pulley or flywheel, but they will have limitations in the smaller diameter distributor housing.

 

More useless knowledge from yours-truly! :P

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All, I appreciate the dialog. I went with the unilite because the vacuum diaphram failed on the stock unit. I will try to order a replacement diaphram for the stock distributor, but for now I am kinda stuck with this new Unilite distributor and I'd like to get the most of what I currently have. I did purchase the mallory part number 700 resistor as recommended, and I have purchased a new crane performance ignition coil, part 730-0060 PS60 performance coil as part of my attempted upgrade. I will continue to research and I appreciate all the information so far.

Thanks for any further advice on installing what I have.

Jim

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IMO throw that mallory as far away as you can, and do it quickly!! My Z ate 4, 2 on mechanical failure, 2 on electronic failure. They use a LED for the trigger (unilite), and LED's DO NOT like voltage changes. The unit was properly wired and I was using the mallory ballast AND "noise filter". Just use the stock unit, they are easy to get and rebuild. I picked up a 3 pack on flea bay for 29.95$ with shipping.

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  • 2 weeks later...

All,

I have ordered a stock distributor, which I will checkout and rebuild eventually, but for now, I'd like to get my Unilite working with my Z. Please try to avoid responding with "throw the unilite away" type responses if possible. I hate to waste the money I have spent that way.

 

I am thinking I have something not wired correctly.

 

I wanted to ask for more help if possible....here is what I have done so far.

1) Removed old distributor mechanically and disconnecting red & green wires from terminal block on driver's side fender.

2) Install new unilite mechanically with Unilite power filter in harness

3) Install mallory ballast resistor

4) Disconnect blue wire from harness going to negative side of coil, taped up blue wire, no longer required...right?

5) Connect Z harness black & white wire from positive coil to ballast resistor. This is the ignition switch wire....right?

6) Connect red wire from Unilite to same end of ballast resistor where black & white wire from Z'z harness (ignition switch).

7) Fabricate wire, connect from positive on coil to other end of ballast resistor. Note, this is only connection to positive coil terminal.

8) Connect brown wire from Unilite to engine ground

9) Connect green wire from Unilite to negitive on coil. Note, this is the only connection to negitive coil terminal

10) Red and Green connections from "Terminal Block" on inside of driver's side fender remain not connected to anything.

11) Mated black wire coming from the condenser on my Z to distributor housing...approximate location of stock installation for this wire.

12) Transitor Ignition Unit is still plugged up.

 

Crank, crank, crank. Getting really good spark, but no fuel is getting into cylinders.

 

Double and triple checked TDC, it is correct.

 

Fault isolated all circuits per Factory service manual..all continuity and voltage checks perfect!

 

What is next? Any suggestions greatly appreciated.

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4) Disconnect blue wire from harness going to negative side of coil, taped up blue wire, no longer required...right?

 

12) Transitor Ignition Unit is still plugged up.

 

Crank, crank, crank. Getting really good spark, but no fuel is getting into cylinders.

 

Double and triple checked TDC, it is correct.

 

Fault isolated all circuits per Factory service manual..all continuity and voltage checks perfect!

 

What is next? Any suggestions greatly appreciated.

 

Coincidence that yours is the first post I see. Not a stalker...

 

2. Leave the blue wire connected. It sends the "break" signal to the ECU to fire the injectors and to the tachometer. There's also a resistor in line to the ECU, that the ECU needs to use the signal correctly. That's probably why you're not getting fuel, the ECU isn't "seeing" (feeling?) the coil activity.

 

4. Unplug the transistor ignition unit. I don't know if it hurts to have it connected, but I do know that the car will run without it connected, if you have an ignition module at the coil, which you do. You're getting spark so it must be working. Watch out for loose wires on the disconnected end, some of them will be hot when the key is on.

 

I didn't really look at your other connections. I think that your main problem now though is the disconnected blue wire.

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  • 4 years later...

Crank, crank, crank. Getting really good spark, but no fuel is getting into cylinders.

---

Fault isolated all circuits per Factory service manual..all continuity and voltage checks perfect!

Found this discussion because I'm having the problems Jimzee78280 had in post #12... especially "Crank, crank, crank. Getting really good spark, but no fuel is getting into cylinders."

 

Just bought a 280Z that wasn't running... it has a Mallory Unilite distributor the previous owner installed... he said he had it running... 2 years ago, and lost time to tinker with the car so he sold it.

 

Called MSD (owns Mallory now) and the technician was surprised to hear the Unilite is on an EFI car. He said it needs a tachometer adapter so the ECU knows when to trigger fuel injection. Also, searched "280Z Mallory Unilite" and the first hit is http://www.thezstore.com/page/TZS/PROD/12-4042 where it says "Mallory Unilite distributors will not work with the stock Nissan fuel injection system ECU."

 

Those two things confirm my suspicion that the EFI/ECU is fine (passed all tests in the EFI Bible), but the ECU doesn't know when to fire the injectors...

 

So, do I:

1) Find a way to make the Unilite work? How?

2) Buy a stock distributor at AutoZone... but I wonder what else he's altered/removed from the car that may not allow the stock one to work.

Edited by Jason
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