Hey guys,

I just replaced my 73 stock distributor with another one. What was happening is that the rpm and tach would hop around wildly and then the motor would sometimes die. There's some mechanical wear in there somewhere. After removing and a quick look it wasn't obvious where the mechanical slop was so I guess I'll take it appart and have a look. I saw some posts about the bearing in the bottom but that looks tight at least from the outside. Does it need to be taken appart to see the problem?

Question is, does anyone sell the detail parts for these or do folks just buy a rebuilt one? I'd prefer to buy one or 2 parts and just fix it myself.

BTW, I have experienced the same exact problem on my old 81zx and its not fixed either. Seems to be a common problem once you get to >200K miles. Until now I didn't know what the problem was, now I do.

tks

Don

Considering what it costs to go breakerless now, you may want to punt on the original ignition. Amazon.com or CenturyPerformance.com's price on the Malory Unilite distributor (MAL-4763901) is hard to beat. You used to have to throw down to get those (I did!!!)

Mine is matched up with a MAL-700 ballast resistor and a MAL-29216 Chrome Coil. Looks nice with the MAL-29224 Chrome bracket.

I'm a motorsport auto fan, but not for ignition. You can get a new ignition and a bumper for the price of the Malory distributor at MSA...

Is there some reason you don't want to go with a up grade and use a electronic ZX ignition. They are a great upgrade. I just picked up on from a '81ZX that is in fantastic shape for $25.00 . For a spare. I have been running one in my car for 6 yrs. Started with it in my L-24 and moved it to the F-54 engine now in my 240. Vary simple to install . Just do a search , there is plenty of posts on this mod. If you do need help with this just ask . Gary

Mine is matched up with a MAL-700 ballast resistor and a MAL-29216 Chrome Coil.

Just curious, but why would you use a ballast resistor with an breaker-less ignition? Is this something that Mallory recommends with their breaker-less dizzy, if so why? Or are you not using an breaker-less dizzy?

Actually the question is related to an 81ZX dizzy as well. I've got one in a my 81zx and its rpm has been hopping around the same way as the 240 did. At first I thought that it was the broken magnets which I replaced only to have no improvement. Now I realize after the 240 experience that it is wear slop in the distributor somewhere that causes the problem. Lower bearing?

Actually the 240 is fixed although I'd like to fix the old one as backup. To make the story complete, I actually have a modified HEI ignition from a Honda on the 240 although it still uses the mechanical points. Puts out a helluva spark! Scary actually.

I'd like to fix the ZX too so hence the question about replacement parts. I know I could do much better with Mallory and all that but I guess I'm just

1. cheap

2. Mechanically curious that I just want to find out what went bad and fix it.

3. the 81zx is such a rust bucket that a Mallory dizzy is probably worth more than the whole car.

I suppose that there's a good chance that I can get 81zx parts from the dealer like I got the magnet assembly but I thougth I'd ask here first.

Don

One more note, the reason I didnt' go with a $25 replacement was that I figured something like that might have that same worn out jumping problem. That's why I want to figure out what causes it.

Don

Just curious, but why would you use a ballast resistor with an breaker-less ignition? Is this something that Mallory recommends with their breaker-less dizzy, if so why? Or are you not using an breaker-less dizzy?

The Unilite distributor can trigger an external electronic ignition, the stock coil, or a high output coil. I think most people go straight to the extenal electronic ignition. I didn't do that, I have it triggering a chromed Mallory high output cannister coil. The distributor instructions say in my case the resistor is needed, but if triggering an external electronic ignition module, the ballast can be installed or removed (neat!). The coil instructions say this...

NOTE: Most late model cars are equipped with a ballast or loom resistor. Do not bypass this resistor when installing this coil. If there is no original equipment resistor in the circuit, use Mallory Resistor Part No. 700.

Playing around with GIMP on Linux and my camera. Here is a photo of my ignition setup. I have a bigger image going to my gallery.

... it is wear slop in the distributor somewhere that causes the problem. Lower bearing?

I fried two distributors, one in my green 240 and one in a 260Z. Both times it was the lower bearing. Also had problems with shot springs on the timing advance weights. The springs are pretty easy to fix. When I lost the lower bearings 15 years ago and I assumed that meant the distributor was a total loss.

I've heard that said by others that the lower bearings go bad. I guess I'll just have to take appart that old 240z dizzy just to see what's in there and what it takes to manage. Keep in mind that the end goal was to fix a 280zx one that has the same exact problem so I was gonna use the spare 240z one to learn WHAT NOT TO DO. There's a place (RockAuto?) that sells rebuilt ones for a bit over $110 so that may be the easy out by the time you figure in the time to do all this.

It may take some special tools to get that messed up bearing off, clean up the shaft and put back togetether, not to mention possible spring problems, calibration, etc . I've got plenty of modules so I don't have to be concerned about that. I just figured getting another one at my favorite junkyard that ultimately I'd have the problem again if not right away since these things are practically guaranteed to fail once you get past 200K miles.

Don't make them like they used to I guess.

tks for the comments folks.

Don

OOPs Greenz, I see that you are in Austin. I'm from Georgetown and make the daily drive alternating the 240z, wifes camry, and a suburban. Do you attend the Z club meetings locally?

Don

There is also the Pertronics conversion that many seem to like. Originally I intended to do the ZX dizzy upgrade to my 240 but everyone I came across was pretty worn...the bearing plate assembly always seems to be shot as well as the mechanical advance mechanism. Maybe just my luck!!? Anyway, I decided to go with the Mallory UniLite. Purchased it from Summit Racing for approx $350.00 (with vac adv). It's worked flawless ever since the 240 was put back on the street in 2002. And, besides working flawlessly, it certainly has a lot of HRC!!! (High Rate of Coolness)

Tom