Zed Head

Mopar's old video, from that link above, at 4:44 is interesting. I'm learning stuff.

That would be 'cool'. I think that just watching current with time might be telling. Or temperature rise at constant voltage. Or voltage drop with time. You know what I mean. If there is a change then the rate of change is probably relevant. You're probably right and I over-mystified the situation. But I think that the other stuff I brought up is relevant. It's an interesting subject. Mopar had a dual ballast system on some models. Not sure if one was for starting or if the other came in to play during operation. Looks like maybe the ignition module controlled or switched the other side on when appropriate, according to this article. Check out their igntion tester. They even modified it later to test the ballast resistor. How complex could it be!? https://moparconnectionmagazine.com/gallery-mancini-racing-reintroduces-the-orange-box-videos/

Even if it doesn't help, it's always good to have a spare ignition module ready to go. That original one is going to fail eventually, probably sooner after you get the engine to rev right. The typical parts failure cascade.

p.s. an aside, kind of - if the resistance is moved to the coil then the heat goes with it. Something to consider. p.s. 2 on the sparking - the fact that spark jumps to the body means that the ignition system is working correctly. You have an insulation problem. Keep the current inside until it gets to the spark plug. p.s. 3 the other stated purpose of the ballast resistor - to allow proper current through the coil when the starter is creating a voltage drop. If you replace the ballast with a high resistance coil you lose that current during starting. In theory the engine should then be harder to start. I'm just pulling out odds and ends. It might be a combination of many things. In manufacturing R&D they typically stop when it "works" and can go to market. Many of the compex systems in automotive are fixes on top of fixes.

It's hard to find scholarly articles on the internet because everyone is trying to make money off of them. You have to pay to read them. Even 60 year old articles. $35 just to read a paper from the 50's. I try to learn what I can inexpensively. Here's an example, linked below with an image, of a crumb of knowledge that disappears when you click through. Gotta love the Google machine. I really should sign up for a course at the local college so that I can use their library. Things like this drive me closer. https://scholar.google.com/scholar?hl=en&as_sdt=0%2C48&q=ballast+resistor+coil+ignition&btnG= 1932! Theory. Who knows if it went in to practice. https://digital-library.theiet.org/content/journals/10.1049/jiee-1.1932.0001

Here's a possibility, that I understand in concept but don't know exactly how it would work. The ignition modules have a feature designed to cut current after a certain amount of time fi the key is left on. Maybe that is what is happening. When the current is cut a spark happens and the injectors squirt. Actually, the current would have to be cut three times for each click, so that would mean every 10 seconds. You should be able to see it on a meter. Of course, that suggests that the current comes back on again, so the feature is not one and done. It's more like a setting on an oven dial. The FSM says within 10 seconds and calls it a lock preventive circuit.

You should describe the state of the car at this point in time. Coil, ignition module, throttle body, any wires left hanging, etc. Is the coil still whining? Is that why you're standing there with the key on? How many 30 second intervals have passed where you heard the injectors click? Is it actually 30 seconds or just your guesstimate of time passed? Are you sure that your friend isn't messing around with something in the cabin? Does he have other odd devices wired in somewhere? The car seems possessed.

The ballast resistor is actually an early form of current-limiting. Probably too slow and imprecise to allow lower overall resistance. An interesting piece of technology. Kind of a shame that everything today has been shrunk down to microelectronics and computer code. https://hardwarebee.com/ballast-resistor/ p.s. after you absorb the concept of the ballast resistor you realize that you can't just use a higher resistance coil and remove the ballast and get the same result. Pretty sure that I have been guilty of suggesting that in the past.

zspert's posts about the V-3 system might have some clues. It would be great if he pulled them out in to a separate thread, but you can find them in this one. Post #2141 if it doesn't click through. There are two more somewhere before it. p.s. has anybody noticed that the search function does not work at all? Nothing, even if you copy the phrase exactly as it is in a post, Search does not find it. "Did someone say V-3 kit" returns absolutely nothing.

Yes, that looks like the stock 260Z distributor. @SteveJ would know for sure, he has one. It is electronic. The ignition module is under the glove box on the kick panel. Looks space-agey with aluminum heat sink fins. Watch the tachometer needle when the problems happens. If it is jumping around, not following engine speed, that's a sign of a failing module.

Post a picture. 260Z's had electronic ignition. They were the first Z's to get it.

Of greater capacity. The crankshaft position and the oil pickup position do not change if you change the capacity of the pan. If the pickup position is changed then an argument can be made for a dipstick that has different marks on it. The marks indicate level. When people say add the quantity that the factory said to use then mark the dipstick, there is an assumption that the oil pan capacity is what the factory had in mind when they put the marks on the dipstick. If you're not sure what dipstick or dipstick tube that you have then remarking your unknown dipstick is valid IF you have the factory oil pan. Most of the statements in this discussion need to be qualified.

Let's call this a "bench building" thread, like bench racing. No verification, lots of pontification. On the dipstick, if you put a larger oil pan on your engine do you change the dipstick? No. The dipstick is there to verify the proper "level" of the oil, not the quantity. For some of the very reasons that you described, windage and the pickup tube entrance. Both of those are determined by level, not quantity. Your logic went awry, you made the points against your own "no". Anyway, I was hoping to learn something interesting regarding the odd pressure readings. Didn't learn anything. Lots of contributions, not much returned.

Thanks RacerX but I already posted that drawing of the oil passages. And loose and missing are not the same thing. And, you can't know the quantity of oil that will pass through a loose or missing oil galley plug or the pressure drop that will result if a plug is loose or missing. You can only assume. Anyway, this looked like an interesting problem but it's not clear at the end here that the problem was anything more than just a goofy gauge or a piece of crud stuck in the gauge port. Lots of parts moved around and removed and replaced but no reason shown or even guessed at for the low gauge reading. For some unknown reason the gauge now reads oil pressure that is perfectly suitable for the engine. The dipstick is meant to show the distance of the oil from the bottom of the block. That distance could have been confirmed while the oil pan was off. The dipstick has to match the dipstick tube. Carry on.

Any chance you could tell the people what you saw while you were in there? Before you move on to the new wiring problem? A story that ends unresolved is very disappointing.

Did you turn the Nissan gauge by the body and not by the nut at the base? You can twist the wires off inside. Sounds like an electrical problem. At least you have good numbers. Mystery unsolved. Cause not found.

Here's another interesting thread from before my time on the forum. Says that there are also crankshaft plugs. Makes sense, anywhere a passage is created there will be an end that needs plugging.

He said he checked it in post #55. But that would not cause his system pressure problem. It just bypasses the oil filter. Won't be a surprise if the problem remains when it's all back together. Here's a question for the engine builders. Maybe it's in Monroe's book. Are there oil galley plugs that could be loose or missing? Of course, they would have to be internal since there are no huge oil leaks. I just did a quick Google and found a reference. Different engine, still Nissan. https://www.311s.org/phpBB3/viewtopic.php?t=10024

Even if they were over-torqued that's not going to be the cause of your problem. You've spent a lot of words on torque settings. How did the parts look? The pickup tube and the bearing clearances? Not seeing any signs that you found the source of low pressure.

If you read around you'll find that the Mallory distributor seems to be of high quality. I posted a link to a site that might have replacement ignition modules/trigger sensors (the red part inside the distributor). Z car distributors aren't a "buy new and replace" part anymore. They all take some extra work and many of the options don't have the best advance curves for the engines. After doing some reading it looks like if you do decide to disconnect the MSD module then you'll have to use a ballast resistor to avoid damaging the Mallory module. They were developed before current control technology was incorporated in to the modules. So, don't just disconnect the MSD and run it, or you might burn up the Mallory module. So, no easy routes to a fix. If you do buy a new distributor and use it with the MSD and find that you still have the problem at least you'll have a spare. You could probably replace the MSD with a GM HEI module as a cheap test. But, still takes some electrical knowledge. We could go round and round for quite a while.

Here's an interesting one, ending today. Probably going to be RNM, based on the seller's comments. A PO "rebadged" and retitled it with tags that don't match the VIN. Then it got retitled with a brand new AZ VIN. Just sold for $19,600. The seller said he had more in it for restoration costs. https://bringatrailer.com/listing/datsun-240z/

Just posting this for future reference. Don't know if one of them fits yours. Get the number off of your part. https://www.summitracing.com/search?SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=Mallory Replacement E-Spark Modules

I would just focus on the MSD and the Mallory parts and the coil to start. Look for signs of overheating, clean things up, assess the quality of the parts. Be careful moving things around the Mallory module might be adjustable. p.s. I didn't really study your pictures before. Looks like you have the full Mallory distributor. Not sure if you can get replacement parts for those.

The heat comes from the electrical current. It might be worthwhile to disconnect all of the connections and clean then up then see what happens. Bad connections can cause heat, and they can also open up after they get hot. It might not be one of the two ignition modules. Then you'll know exactly what you have and what state the parts are in.

That's an old original Mallory Unilite. I don't know much about them, except that I think that Mallory sold a complete distributor but might also have sold a conversion kit. I think that you have the original light triggered Unilite. The black disc on top has a vane that breaks the light beam. I think that Pertronix might have converted the "light" trigger (hence Unilite) to magnetic. Here's an old thing I found. https://www.zhome.com/ZCMnL/tech/MalloryDist.htm Since you're in there you might as well check your mechanical and vacuum advance mechanisms. See what shape the distributor is in before deciding how to fix it.