Petronix ignition install for 240Z

[ainokoz]

I'm having my '73 240Z engine rebuilt and am trying to install the Petronix ignition system in the stock distributor. I purchased the unit, but the garage that is rebuilding the car is telling me that the system isn't fitting correctly in the distributor. Something about the unit not being able to rotate.

Can anyone tell me if the system does just "drop in" or is there something else that needs to be done? I have a manual transmission if that info is needed.

Thanks

[EScanlon]

You'll find that most people (myself included) who have done the mod to electronic ignition have used the E12-80 Nissan distributor mod to their 240's. That's a distributor from a later year Z (78 or 79, others will undoubtedly chime in and correct me).

I know the problem your mechanic is referring to, as I've done that same mod on my 1600 and 2000 Sports Roadsters.

The problem is that the jig they use to drill the mounting holes for the Pertronix base plate has the centers of the holes just slightly off and the sensor on the plate rubs against the magnet holder that mounts over the dwell nut....mostly due to the tape they had to add to the magnet to ensure the magnets don't fly out of the holder.

The jig they designed years ago to hold the plate did NOT have the thickness of the tape being considered as part of the diameter of the magnet holder. As a result, the magnet ring with the green tape RUBS against the face of the sensor and it's impossible to move the base plate out enough to provide a gap of any size. I called Pertronix about this and unfortunately there's some bozo there who is convinced that since they've been manufacturing them for over 35 years (his words) that there isn't anything wrong with their manufacturing process and the problem MUST lie with your car's distributor.

(Makes you wonder how their QC dept must do their job.

"Did you do it the same way we've been doing it, even though there's been a change?";

"Yes!";

"Then it MUST be OK. Tell the customer he's full of beans.")

The solution I came up with was to very carefully slot the mounting holes (and we're talking THOUSANDS of an inch) such that you could in fact move the base plate and the sensor away from the magnet holder. Be careful of this, remember you only need enough clearance for the sensor and ring to NOT touch. Be sure that your distributor has no play in the shaft (no wobbling back and forth) and you should be fine.

FWIW

E

[MikeW]

I don't recall having any problems with my installation. To help clarify what Enrique is describing I've attached a picture of my setup.

[DeesZ]

I had no problems of that sort with my installation..... but yes, there was very little clearance as mentioned above - a bit less than the installation instructions called for if I recall correctly. I'm pleased with the unit and its performance.

[ainokoz]

Thanks for the info. I printed out the messages and passed it along to my garage. Hopefully they'll be able to cut the notch and make it work. I also purchased a 280ZX dizzy with the E-1280 module last night on e-bay if this doesn't work out. Now the 280ZX dizzy should be a direct drop in, right?

Thanks again for sharing the knowledge.

[Arne]

The ZX dizzy requires the ZX mounting tower as well. But with that, it's about as bolt-on as it gets.

But check the one you get carefully, as many of these used ZX dizzies have worn bushings and/or bad vacuum advance units by now.

[ainokoz]

Is the "ZX mounting tower" also called a distributor support? I see a distributor support in my MSA catalog---are they the one and the same?

As I don't see anything about replacement bushings, and if that is bad, should I just go about getting a rebuilt one at the local parts store? We don't have a lot of junkyards here to pick from so I'm pretty much left to the catalogs and local parts stores. Thanks for the info.

[hd240z]

I don't have a MSA catalog to look at, but it sounds like the two items could be the same thing. If you are lucky the distributor support will be included with your ZX dizzy. The ZX support is similar to the 240 support in that it is about 2 inches tall and the bottom of the support will have two mounting holes to attach it to the engine. The top part of the support is different in that it has two mounting holes to attach to the distributor and provide the timing adjustment. The 240 has only one mounting hole. Unless your 73 is different from my 71.

I doubt your local parts store will have replacement distributor bushings. You will probably have to find a machine shop to make one if you need it. Even the distributor vacuum advance may be a little difficult to locate. I had to get my replacement from the Nissan dealer.

[Arne]

Yeah, different name, same part. But as was mentioned above, don't buy one until you see if the dizzy you have coming has one already. A lot of them do. Was there a picture in the auction? Give us the link and we can look at it.

As for the bushings, my advice would be that if the bushings on the one you get are bad, use it as a core for a rebuilt unit.

[xray]

...be careful with the 280ZX distributor swap...may cause your tach to stop working.

http://datsunzgarage.com/engine/

"A 240 tach will not work with this setup. It uses a inductive pickup that isn't compatible with the signal from the E12-80. There are two solution: Replace it with a 75-78 280Z tach and connect the tach sensor lug to the - terminal on the IC module. If the tach jumps around, solder a 7500-10,000 ohm resistor inline with the sensor wire to reduce the signal voltage. If it still won't work buy a Autometer #3990 black face tach."

Some folks report no issues with the swap, however. I did the Pertronix install just for this reason.

[Arne]

...be careful with the 280ZX distributor swap...may cause your tach to stop working.

http://datsunzgarage.com/engine/

"A 240 tach will not work with this setup. It uses a inductive pickup that isn't compatible with the signal from the E12-80. There are two solution: Replace it with a 75-78 280Z tach and connect the tach sensor lug to the - terminal on the IC module. If the tach jumps around, solder a 7500-10,000 ohm resistor inline with the sensor wire to reduce the signal voltage. If it still won't work buy a Autometer #3990 black face tach."

Some folks report no issues with the swap, however. I did the Pertronix install just for this reason.

I'm certainly aware of that claim by Bryan Little, but I've never heard from anyone who has experienced that issue. I've tried mine on three different 240Zs, all the the 4-wire tach. Worked fine on them all. I also know of several other people running the ZX dizzy on 240Zs, with both 3-wire and 4-wire tachs. All of them work. So I'd have to say that it works in more cases than not.

[ChrisA]

All of them work. So I'd have to say that it works in more cases than not.

Ditto, runs fine on my stock 73 tach. Had a MSD 6AL and MSD tach adapter, swapped it out for the ZX dizzy with E12-80 module. I actually think the car runs better on the Nissan parts than the expensive MSD stuff.

Somewhere on the net is a tech article to rebuild the dizzy. Here it is....

http://www.jrdemers.com/280ZX/distributor/distributor.html

FWIW,

Chris A.