Easiest way to eliminate points on 240z

[jmortensen]

If you just install an MSD, the MSD will still be triggered by the points. For the OP's purposes, the Pertronix is the important part. I like the ZX distributor upgrade wiring is so stupid simple that even I could do it myself, and I disconnected and disabled the vacuum advance, which is almost always broken on these distributors IME.

[Pop's Z]

Re: "The '79 ZX dizzy won't work with the '73 tach." I don't know where that info comes from, but my '73 tach works perfectly with my '79 ZX dizzy w. the 12-80 module...just sayin'

Cheers, Mike

[EScanlon]

The Pertronix or an equivalent (if there is one) is likely the easiest and will work with the stock tach. The '79 distributor might be better but is not easier and it will not work with the stock tach.

Sorry, you have it completely backwards.

I have the original 71 tach (4-wire) in my car and I'm using the 79 ZX Distributor.

I tried the Pertronix in three other cars (two Roadsters-1600 & 2000, and a 73 240), and found that I then had to monkey with the wiring to get them to work. Finally got it to work on the Roadsters (Tach is not part of the ignition circuit in those two) but had problems with the Z's Start, and Run settings with the standard coil and resistor wiring. Finally removed the resistor and was able to run and start, but then found the coil over-heating. At that point I pulled the unit and shelved it. I guess if I'd gone ahead and upgraded the coil, removed the resistor it would have worked, but I was never very comfortable with simple tape holding the small magnet in the piece that replaced the rotor.

The tach has never been a problem with my car and has been working fine since 2001 when I bought the car WITH the 79 dizzy installed. Since I had the problems with the Pertronix installation on the 73 I never really ran the car to state that the tach was trouble free, it may have been, but I can't state that as I didn't notice it.

E

[Stanley]

Off topic since it doesn't eliminate points, but if you're going electronic because the stock distributor is worn and new ones are NLA (MSA had them up til a couple years ago) you can get new ones from Japan (see Nostalgic Hero ads and elsewhere). They probably have the sportier JDM or euro advance compared to detuned USDM.

[Jarvo2]

I've been seeing the re-manufactured ones pop up on eBay as well. Very reasonable price, just need to keep an eye out for them.

[EScanlon]

As a side note, the ONLY function of the distributor IS to distribute spark. The Advance mechanisms you mentioned are an INTEGRAL part of the distributor's mechanism to keep the spark at the proper point of the combustion cycle.

2¢

E

Not really clear what you're saying there. Maybe you meant that distributor is a misnomer, or a misleading name. The "thing" called the "distributor" by most that work with it, contains the spark triggering device and the timing control mechanisms for doing that at the appropriate time based on engine conditions, along with the spark distributing hardware.

It just comes down to how far in to it you want to get. You can go simple and "slap" any old combined spark distribution, triggering and timing control device (aka distributor) in there or go a little deeper and think about the other functions. That was my intended point.

The 79 ZX probably has a decent timing curve. But the later ZX's have some radically different curves. There are ways to make things worse. No good reason not to consider it.

Ahh... it's obviously a thing of "deep" thought.

Nonsense. While you can attribute all sorts of complex theories and supernatural heeby-jeebies to it, it isn't as esoteric as you make it to be.

The "Timing" of the engine has all been calculated from the beginning of the engine's design, before the first casting of the block even gets poured, the timing is set. Does this mean we need to consider the angle of the even number cylinder axis in relation to the odd number cylinders in a V style engine before we can effect a timing change? Engineers do so during the design, and if you're considering a major change (engine points system to individual cylinder coil/spark systems) then yes you should also. But were not discussing the theory of internal combustion engine timing nor the considerations required to effect system changes on these engines.

The question is in the title of the thread: "Easiest way to elinminate points on 240Z", and not "Obfuscations on Internal Combustion Timing that confuse all."

The only way to get away from the Mechanical spark generator which are the "points" is to go to an electronic unit. Whether Pertronix, MSD or the 79 ZX Dizzy is the next consideration. (Yes you could go to the individual cylinder spark systems available on newer vehicles but the first word in the title is EASIEST.)

Of the three methods, only the 79 Dizzy is a simple Remove and Replace process when done properly (meaning you don't spin the dizzy and you take care to match the position) even including the vacuum and mechanical advance systems.

The Pertronix CAN be made to work and so can the MSD, but even the experienced mechanics who have done that mention that they still have to "play with it".

E

[Zed Head]

Getting a little meldramatic, aren't you.

Let's assume, then, that "easiest" means the least amount of wrench work, with the lowest potential for complications. I think that Pertronix wins in that scenario. Take the "distributor" cap off, remove points, install Pertronix unit. Tach works, car runs. I think that all you need is a Phillips head screwdriver. Pertronix is the easiest.

[Zed Head]

For the record, I wasn't trying to jerk anybody's chain or confuse the issue (for some reason there seems to be a time limit on editing posts, hence the new post).

I think it's fair to respond to the statement that the 79 ZX is a simple "remove and replace" operation. It's not. The ZX distributor requires a mounting base for an electronic ignition distributor. The 240Z points distributor base will have the dist. clocked incorrectly if the correct mounting base is not used, making it difficult or impossible to set the static timing. If the OP buys a rebuilt distributor from any auto store he will not get the base, he will have to source it from EBay or CL or a salvage yard. Kind of another illustration of my point that there's always something else to think about when you get in to these kinds of upgrades.

I'm a big fan of more information than I need when I start a project. Getting the perfect amount is almost impossible, and the only alternative is not enough info. to do the job right.

[ninjazombiemaster]

I had the Pertronix in mine for a while, and it worked great (until I carelessly routed its wires in such way that the rotor sliced it after some routine dizzy checks). Best part is if it ever does fail, you can retrofit the points back on in under 10 minutes and 10 dollars - which is what I did at that time.

[EScanlon]

Checking my installation further, since it was done 12+ years ago, apparently my swap included the proper base for the ZX dizzy, which in my mind didn't register.

As a result, in straight SIMPLE terms, the Pertronix should be the easiest.

However, my experience and others do show that there CAN be problems with it's installation and subsequent short term service life. My problems may have been due to a sensor plate that was slightly off spec, whereas others that have written their trials and tribulations mention dizzy bearings and (separately) over heating of the parts with eventual failures.

Arne has an excellent test/trial/result article where he goes back to Points after trying the ZX, the Pertronix and one other (which eludes me at this point). However, he went back to the points and was completely happy with them.

I searched high and low for references to the proper dizzy base and the only thing I found was post #5 in this thread:

http://www.classiczcars.com/forums/showthread.php?t=43498&p=374406&viewfull=1#post374406

Maybe there are other incidences, and if you know of them it would help if you posted them here.

E

[Oiluj]

I read a few posts on how some have had issues with the pretronix set-up, and don't doubt what's been reported, but I've never had a problem.

I've Installed them wihout issues in 3 different 240Z's and in a 70' Capri. Worked flawlesly every time.

Maybe Pertronix had a quality problem or the seller sent the wrong model?

[Zed Head]

This is probably the most popular thread on installing the ZX distributor, a link the OP could use anyway if he decides to go that way (with attention paid of course to the fact that the writeup is for rewiring a 77 280Z setup). It shows pictures of the two different mounts also. The problem is in the position of the lock down screw.

http://atlanticz.ca/zclub/techtips/distributor/index.html

Looks like he has plenty of choices. Wonder where he went...

Edited December 23, 2012 by Zed Head