Pertronix vs Points

[StinkyCheese]

I was having a problem with my Z cutting out at 4000 rpm so I came to these wonderful forums and did some searching. There are quite a few threads that say, "I just fixed this by installing a Pertronix electronic ignition". There are also quite a few that say, "install a dizzy from a 280z and that fixes it." That seemed like an easy solution, so I bought the Pertronix gear.

I installed the Pertronix and it works great, but now my tach doesn't work! So back to the threads I go for more research. This is also a common problem for Pertronix igniters. It just seemed like I was trading one problem for another. :stupid:

I kept reading several people saying, "points ignitions worked great for cars for a long time". And a lot of people that don't trust their electronic ignition and keep a spare points system in their car.

After all this screwing around, I have to ask - the solution to cutting out at 4000 rpm is to put electronic ignition in. But what's the root cause of the 4000 rpm drop-out? Is it just that I have a 40 year old distributor? And if that's the case, wouldn't it make more sense to buy a rebuilt dizzy?

[Z train]

Points belong in museums-not street driven cars.

[Zforce]

I have been using the pertronix in a mallory dizzy since 2003 without any problem at all. And I don't think the 4000 rpm barrier even exists, at least not ignition wise. I think people are installing the pertronix and then driving the crap out of thier cars and uncovering other problems and blaming it on the pertronix. Fuel system problems are more likely the real issue. My car was cutting out at 4k also, but after installing the sm needles that problem went away,so did rich idle problem, smelly exhaust and my plugs are clean.

Your tach should work fine, go back over the wiring, red pertronix wire at 12v ignition before the ballast resistor and black wire at neg side of coil, that's it.

[StinkyCheese]

Points belong in museums-not street driven cars.

yeah, I read that sentiment a lot, too. Not buying it!

[Arne]

These are simple cars. It really doesn't much matter how you trigger the coil, just that everything is up to snuff. Points will work, so can electronic ignition. Use whichever works best for you.

For your question - there are several potential root causes of the 4000 RPM wash-out. Since you were experiencing this with points, but it went away after the Pertronix was installed, I suspect a bad (or inadequate) condenser. Just a guess, diagnosing things like this over the Internet is difficult.

As for the tach, a '73 should be fairly simple to make work. I think those are the more modern tachs that just need a connection from the negative side of the coil?

[Z train]

yeah, I read that sentiment a lot, too. Not buying it!

I'd agree with you,but then we'd both be wrong.

[ajmcforester]

Personally I like the points over the Pertronix system.

Z train quote:

Points belong in museums-not street driven cars.

Statements like this is what you get from people that don't know how to adjust points properly.

I've had both systems on my car. My first Z had points never switched over. When I got the second car it had a pertonix system it when I bought it. After cleaning the distributor it worked well for about 3 months and burned out and was the first time a Z left me walking. I switched the car over to points at least if they have a problem I can makeshift them to get home. Performance wise I didn't notice any difference between the two systems. My advise don't switch it is not worth the money points are not hard to adjust.

StinkyCheese Quote

I was having a problem with my Z cutting out at 4000 rpm so I came to these wonderful forums and did some searching. . .

I've had this problem with the 2 Zs I owned, what I found it to be was the breaking-plate. I found the ball bearings created a groove with ridges I buffed it smooth, and fixed the problem.

[Z train]

1)Personally I like the points over the Pertronix system.

Z train quote:

Points belong in museums-not street driven cars.

2)Statements like this is what you get from people that don't know how to adjust points properly.

3)My advise don't switch it is not worth the money points are not hard to adjust.

1)What YOU or I like is irrelevant.What is a superior system is the point.

2)Wrong-statements like come from 40 years of wrenching.Owning two Z cars doesn't qualify you as a ingintion expert.

3)People really shouldn't follow your advice if they want to improve their cars.

Edited July 2, 2011 by Z train

[Arne]

I've had both systems on my car. ---snip--- Performance wise I didn't notice any difference between the two systems.

Now that I have gotten the Pertronix and new Crane coil working properly on my car (finally), I have noticed a couple of small improvements over well-adusted and maintained points. The car needs less choke to start, and the choke can be released sooner. Perhaps a little less cranking required to start as well.

But really, that's about it. So if you don't care about the minor stuff like that, and don't mind maintaining the points now and then, stick with them.

Oh. Yes, I do carry a set of points in the car, just in case the Pertronix goes out. I'd do that with a ZX ignition too, plenty of those E12-80 modules have died w/o warning as well. So it's not just a Pertronix thing.

But on the flip side, I carried a spare set of points in the car when I still had points, too.

[beermanpete]

On a stock engine the points are adequate. The primary advantage with the electronic ignition is reduced maintenance. If the eninge is modified for higher power (especially at higher RPM) the points type ignition shows its weaknesses.

As for the 4000 RPM cut-out problem, we had a similar problem but it occured at about 5000 RPM. The problem turned out to be the wrong points cam. The lobes were too high and pointed causing point bounce at high RPM. Fortunately we had another distributor with a lower, more rounded lobe profile. Now that we got that sorted the car runs great to red line.

Your tach problem might be due having the current sensing (4-wire) type. If it was working properly and the only change was the Pertronix module then the tach must not like the current pulse shape of the Pertronix. Did you eliminate the ballast resistor or in any way modify the wiring near it? The wiring goes back and forth from the instrument panel and the coil a few times. You might have simply unhooked the tach without knowing. Otherwise, try a tach from a later year. They are the voltage sensing (3-wire) type. Or use a new aftermarket tach.

[StinkyCheese]

Update - turns out i had the tach wired wrong, I just played with it like you said, Zforce. So... it runs great (as before) but now I get a tach, too! However... I took it for a nice long ride, running it hard. Lots of power, feels great, and then it started hiccupping at 4000 rpm again! Aaaaaaahhhh!

I let it cool all the way down and poked around some more. I took my daughter out for a ride to show her -- it didnt cut out again, until it was up to temperature. Any ideas? (I havent searched the forums yet..)

[Arne]

When you installed the Pertronix, did you also replace the coil? Do you have a condenser/capacitor connected to one of the terminals on the coil? And lastly, do you still have a ballast resistor connected?