Ducer Posted January 13, 2012 Share Posted January 13, 2012 (edited) Hey guys, I have an early 74 260z and Im running the stock distributor with a stock coil. I since bypassed the ballast resister and am running 12v constant to the coil and it's been running great. I was wondering was the 260z ever made for 12v constant system? As I know the 240z's were points and 12v's can reduce the life of the points and cause jumps. The 260z as I read is "Electronic" but it has a ballast resistor from the factory. Now Im assuming that the 260z's electronic distributor system was not meant for 12v? Anyway, I just bought a 1979 280zx Dizzy with the E12-80 ignition module box on it, and I also picked up the ZX mounting base at the pick a part today, BUT my main concern is ..........Is there a big benefit from upgrade the ZX opposed to the 260z's stock electronic system running at 12v constant? And If it is beneficial, and I do the 280zx dizzy upgrade, can I run a MSD blaster SS coil opposed to the old school cylindrical type? Coil is a coil? In addition, on the 260z there are 2 wires coming out of the dizzy, a green/white and a green/red which I believe is the "pick up?" Which wire is the tach sending wire anyway? are these green/white green/red pick ups related to the tach, or is it the green wire on the Negative of the coil which is related to the Tach? And will I lose my TACH? or is there a way to wire up the Tach to work after the ZX dizzy swap? Thank you very much. I await to be educated. Doing the swap seems quite straight foward, practicum is easy, theoretical eludes me a bit. Is it worth doing or "don't fix what is not broken?"" Edited January 13, 2012 by Ducer Quote Link to comment Share on other sites More sharing options...
Leon Posted January 13, 2012 Share Posted January 13, 2012 The FSM has been instrumental in helping me deal with my early 260Z. I suggest you first reference the FSM (hint-hint: the wiring diagram and ignition sections) and then try the archives for some of your questions. I will say that I stayed with the 260Z's stock ignition versus a ZX distributor because I did not see much to be gained (and rebuilding the ZX unit didn't seem worthwhile). If you plan to run the ZX unit, I would at the very least take it apart and regrease. I found that my unit had a broken ball bearing carrier on the breaker/advance plate (typical problem), and then found that a new breaker plate is about $75 shipped while a refurb'd ZX distributor is about $100. I decided not to spend any money on it and am now going to fully programmable EDIS, as it is a truly worthwhile upgrade over any distributor ignition system, for the Z anyway. I saw no reason to get fancy coils and distributors when I could have a rock-solid, crank-triggered ignition system that I can completely tune with the press of a key for a few hundred bucks. Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 13, 2012 Share Posted January 13, 2012 (edited) The ballast resistor reduces current flow through the whole circuit. So the electronic ignition module and coil will now have more current flowing through the primary coil charging circuit. More current = more heat. The odds of an ignition module or coil failure are higher now, especially considering the age of the parts. There's a lot of good reading out there about your other questions. Wire colors are in the FSM and wiring diagram. The swap is pretty easy, but you'll have different timing advance curves afterward. Edited January 13, 2012 by NewZed Quote Link to comment Share on other sites More sharing options...
Leon Posted January 13, 2012 Share Posted January 13, 2012 The ballast resistor reduces current flow through the whole circuit. So the electronic ignition module and coil will now have more current flowing through the primary coil charging circuit. More current = more heat. The odds of an ignition module or coil failure are higher now, especially considering the age of the parts. There's a lot of good reading out there about your other questions. Wire colors are in the FSM and wiring diagram. The swap is pretty easy, but you'll have different timing advance curves afterward. Spot on with the resistor comment. Bringing up the timing curve is a good point. One of the reasons I wanted to get rid of the 260Z distributor was because the timing curve does not match my setup. It has a lot of mechanical advance (26deg!) and I'm running triples Webers, which means there is no vac advance. The result is that my base timing can't be more than 10BTDC and there is no load sensing advance to boost fuel economy, therefore the spark timing is far from optimized for the operating range of the engine. Quote Link to comment Share on other sites More sharing options...
Ducer Posted January 20, 2012 Author Share Posted January 20, 2012 Spot on with the resistor comment. Bringing up the timing curve is a good point. One of the reasons I wanted to get rid of the 260Z distributor was because the timing curve does not match my setup. It has a lot of mechanical advance (26deg!) and I'm running triples Webers, which means there is no vac advance. The result is that my base timing can't be more than 10BTDC and there is no load sensing advance to boost fuel economy, therefore the spark timing is far from optimized for the operating range of the engine. So I had purchased a new ballast resistor months ago, and my memory is so horrible I lost it. There goes $13 bucks. I picked up a 1979 280zx dizzy with the E12-80 and it works great as I tested on the work bench. My question is that this particular distributor has dual diaphragm a vacuum advance and I believe a vacuum retard, Can someone tell me which one is which? The outter one on top I assume is the vacuum advance. And is the inner bottom one a suck type or a blow type diaphragm? Look at the distance! Is the Quote Link to comment Share on other sites More sharing options...
Justinp551 Posted March 1, 2012 Share Posted March 1, 2012 What I am learning from reading all these and other posts is that the main benefit of the zx dizzy upgrade in a 280 is the ability to run full 12v all the time. Is the performance worth the money in a 280? Quote Link to comment Share on other sites More sharing options...
NewZed Posted March 1, 2012 Share Posted March 1, 2012 There's not a lot of benefit to the ZX distributor in a 280Z. Nissan dropped the ballast resistor in 1978 anyway. If, by performance, you mean running a wider gap on your spark plugs, then probably not much, for a stock engine. Plus, the later ZX distributors all have lots of vacuum advance designed in, probably to work with EGR. If you're not careful, you'll just get a weird advance curve and a bigger shock when you grab the spark plug wire. Plus, an expensive module replacement cost if the E12-80 module dies. I think that it's popular on the 240Zs to replace points because it's everything in one package, with just a couple of wires to connect to make it work. On a 280Z you could just replace the coil and add an HEI module and probably get the same spark performance or better, but keep the stock advance curves. Quote Link to comment Share on other sites More sharing options...
Justinp551 Posted March 2, 2012 Share Posted March 2, 2012 Newzed, I like your idea. Not to familiar with the hei unit. What's involved? Looking to clean up the engine bay a bit more and get that little bit more performance. Quote Link to comment Share on other sites More sharing options...
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