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MSD6AL with 280z '75 wiring question


tamo3

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I try to hook up MSD 6AL.

 

I found some write up from John Coffey, but I still don't get ingite.

http://www.zcar.com/forum/10-70-83-tech-discussion-forum/21909-msd-6al-ignition-77-280z.html

 

RE: MSD-6AL IGNITION / 77' 280Z
<HTML>Repost on the same topic (another thread) from yesterday...

Here's the wiring instructions: 

1. Red 12 ga wire direct to battery positive. 
2. Black 12 ga wire direct to batter negative. 
3. Red 16 ga wire to ignition switched power - mine is wired to the black wire with the white stripe that went to the original coil. 
4. White 16 ga wire to the points, XR700, Unilite, or Allison trigger. 
5. Orange 16 ga wire to the positive side of the coil. 
6. Black 16 ga wire to the negative side of the coil. 
7. Don't use the purple or green wires unless you have a magnetic pickup for the ignition. 
8. Tach goes to the blade connector on the end of the MSD. 
9. Make sure the red wire is clipped under the little black plug on the side of the MSD. 

- John</HTML>

 

 

My question is where should I hook up white wire?

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Thanks for your help in advance.

 

tamo3

Edited by tamo3
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If I recall right, the problem with using MSD on the 280Z EFI is that the ECU doesn't handle the multiple sparks.  So you might get spark, but no injection.  There's probably a way around it but I don't know what it is.

 

When you say it won't ignite, do you mean there's no spark, or just the engine won't start?  And are you using the stock 77 EFI control system?

 

According to the instructions you should connect the red wire from the 280Z distributor to the violet 6AL wire and the green 280Z wire to green 6AL, for a magnetic pickup, to get spark.  but this may not give injection if the ECU doesn't get its signal.

 

If I was trying what you are I'd connect the tach output wire on the side of the MSD to the blue wire that runs to Pin 1, and the tachometer (copied the relevant text below).  That should/might give the right single trigger to the ECU, if not the tach also.  You might find that you need to split the blue wire apart from the ECU the tach to get them to work.  Just guessing.

 

http://www.msdignition.com/uploadedFiles/MSDIgnitioncom/Products/Ignitions/6420_instructions.pdf

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Thanks NewZed for quick reply. 

 

 

Yes, I don't get any spark.

I unplugged spark plug and put it on strut tower mount and turn the key to start position, but I don't see any spark. I'm still using stock '75 EFI system.

 

I haven't hook up tach cable yet.

 

 

I did not know original EFI is incompatible with MSD6AL. 

 

After your post I research the MSD6AL with EFI incompatibility issue on web and I found this thread.

The MSD technician recommend to bypass original ignition module. Does it mean transistor?

 

http://www.zcar.com/forum/10-70-83-tech-discussion-forum/17137-msd-installation-question.html

 

MSD installation question
I am a little confused by the MSD technician and was wondering if any of you could help. First, my car is a 1978 280z with
fuel injection. The MSD technician has advise me to use the white wire of the MSD unit, however, this is for a points type ignition. I would like to use the magnetic pickup trigger (violet and green wire) of the MSD 6AL however the technician does not know if it will trigger the ecu correctly. My question is has anyone got a MSD 6AL with blaster II coil and 8920 tach adapter(adapter for magnetic pickup ignitions) to work in a 280z with fuel injection using the magnetic pickup trigger (violet and green wire of the 6AL)? 

I have copied my email communication with MSD below. 

Thanks Jeff,

Date: Mon, 17 Jan 2000 11:16
From: Joe LaPille <jlapille@msdignition.com>
To: "'jw90130@goodnet.com'" 
Subject: FW:FW: MSD on 1978 280Z

Sir,
If you are going through the computer and fuel injection, you should use the white wire of the MSD box when wiring this up. I do not know if when triggering this with the magnetic pick up if the tach adapter will trigger everything properly. You will also need to completely bypass the factory ignition module, wherever it is at in this vehicle. Fuel Injected 280Z that we have dealt with all use the white wire of the MSD box and go through the factory ignition and do not use the magnetic pick up. Wire this up with the original coil negative wire to the white wire of the MSD
unit.
You can then use the 8910 Tach Adapter if needed. I was under the impression initially that you were using the white wire as the trigger. 

Thanks,
MSD Tech

 

RE: MSD installation question
Jeff, I think you are getting confused with the magnetic pickup statements. The mag pickup on your stock system just tells the transistor ignition box when to remove the ground from your coil. Think of the transistor ignition box as electronic points, and your tach, coil, and ecu get pulsating grounding signals from your transistor ignition box. The mag pickup is only talking to the transistor ignition box and then the box talks to the coil, ecu, and tach. Soooo... the trans ig box is points for all practical purposes.
 
John Hull 

 

RE: MSD installation question
John, Reading your response, It sounds like the original transistor ignition box is still used as an input to the MSD 6AL. Is this correct?
When I was wiring the MSD 6AL, I removed the transistor ignition completing and routed new wires from the magnetic pickup terminal junction directly to the MSD 6AL(violet and green wires). The MSD does fire, it is just the ecu does not like the signal and does not fire the fuel injection. The signal is very close to the original stock signal just needs some tweaking. I am looking into modifying the signal from the tach adapter so that the ecu is happy. I am not sure if anyone has try this method before or if everyone is using the transistor ignition box as electronic points for hookup to the MSD 6AL. 

Thanks for the reply.
Jeff

 

RE: MSD installation question
I have the exact same system as you guys, I can't remeber wire colours . You don not bypass original transistor box . Take old coil wires feed into box, new wires go to coil . The tach adapter is nessary to trigger rom guage .

 

RE: MSD installation question

Why is the tach adapter even needed? If the transistor box stays connected to the distributor as stock ... and it's output (coil -) goes to both the coil and the tach(splits inside the firewall at the resistor) ... then everything is stock until this signal is used as a trigger in the MSD, instead of going directly to Coil (-). The MSD of course then generates it's own Coil (-) signal that then fires multiple times per the stock unit single fire.

I agree that in this configuration the MSD wants a signal like what points would generate. But what is the tach adapter doing then?

On the other hand:
If you use the magnetic pickup signal into the MSD. The MSD will probably generate firing signals ... but the stock ECU fuel injection system will be confused with that signal, since the MSD is firing several times instead of the normal single time. This would cause the fuel system to run rich ... if at all. Remember the ECU uses the tach signal timing to inject the proper amount of fuel.

As Clint has said: You can do all the wiring directly at the coil ... except for running a new 12 Volt power lead directly from the battery.

ConorP

 

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I think that I got my magnets mixed up.  Apparently, the MSD magnetic trigger is not a variable reluctor setup, it's different, backward, with magnets moving past metal sensors instead of metal moving past a magnetic sensor.  Designed to be used with an MSD trigger wheel.  I'm not sure what the output looks like or how the MSD box uses it.  My mistake.

 

There seems to be a ton of confusion around the internet and even from MSD on which wires are triggering what.  People seem to confuse triggering the MSD box to give spark, with triggering the ECU to cause injection, and also triggering the tachometer to move the gauge needle.

 

Frankly, I don't know why people use the MSD boxes.  Multi spark benefit only at low RPM, with a lot of problems and effort to get things working.  Seems like there are better ways out there to get strong spark with or without the extra spark timing controls or rev-limiting.

 

Sorry, and good luck.

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One thought that crosses my mind whenever I see these problems is to just run a separate coil and ignition module, with the coil just dumping to ground.  Use the coil negative to run the EFI and tach, and let the MSD box do its thing on its own circuit.  The 280Z VR signal should be strong enough to run two modules, I'd think.  If you have a dual pickup distributor you could even use one pickup for the MSD and one for the EFI.  That should definitely work,  they wouldn't even see each other.

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Thanks for your advice.

 

My plan is to run as Fuel Injection and later swap with Triple weber. Since I start rebuilding my car, engine was running, I though it's much easier to back my car on street with fuel injection setting comparing with carb tuning....

 

My distributor is none-CA model, so it's dual pickup. I will try that.

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  • 3 weeks later...

One thought that crosses my mind whenever I see these problems is to just run a separate coil and ignition module, with the coil just dumping to ground.  Use the coil negative to run the EFI and tach, and let the MSD box do its thing on its own circuit.  The 280Z VR signal should be strong enough to run two modules, I'd think.  If you have a dual pickup distributor you could even use one pickup for the MSD and one for the EFI.  That should definitely work,  they wouldn't even see each other.

That's the way I'd do it. The Dual pickup is an advantage in this scenario.

 

As far as which wires to use to trigger the MSD, Use the Violet and Green wires hooked directly to the now isolated VR pickup in the dizzy.

 

A Variable Reluctor pickup and a Magnetic Pickup are the same thing as far as Pickup signal for an MSD or Crane HI-6 ( CD ) ignition are concerned. Doesn't matter if you have a Flying magnet on a crank pulley  or coil type reluctor in a dizzy. The output is the same and that is a modified Sine Wave. So you should be using the Violet and Green wires to trigger the MSD if you connect it directly to the pickup coil of the distributor.

 

Note: If you use the Violet and Green wires you do NOT connect the MSD to any output signals from the OEM transistor ignition box. The Violet and Green wires must be connected directly to the VR sensor lead wires. Note that VR pickups are sensitive to Polarity. MS Manual gives advice on this.

 

The White wire on MSD boxes are for Optical and Hall effect sensors. Those put out a square Sine Wave. 

 

Megasquirt has more info on pickup types.

 

http://www.megamanual.com/ms2/pickups.htm

Edited by Chickenman
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Edit: EFI ECU receives trigger signal from Coil negative terminal. You should be able to get a claen Trigger signal for the EFI by using the MSD Tach output. You may or may not need an MSD Tach adapter. Whatever you do, don't leave the OEM ECU/Tach trigger wire connected to the coil negative terminal with the MSD Box. You'll fry the EFI ECU in a microsecond.

 

Triple carbs will make things much easier... :D

Edited by Chickenman
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Just a thought... but if you are going to swap to Triples down the road, why don't you do things the easy way? Leave the stock ignition in place while you run the EFI, and install the MSD when you switch to carbs. Dead simple that way.

 

The 1975 and 1976 Trignition boxes are pretty weak sauce, but the 77's and 78's are a bit stronger. If you want a stronger ignition, swap in a 79 280ZX Matchbox dizzy while you run the EFI?

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