Zed Head

Just remembered an old problem with the MSD and EFI. Somebody just wrote about it. Might change your decision making process.

I've heard of this problem before. The EFI ECU needs a good voltage pulse on Pin 1 to work correctly. That pulse is supposed to come from the coil negative terminal. If I was trying to do this I might use the tach trigger wire from the MSD 6A and not the 8920. Connect the MSD tach trigger wire to the blue wire that connects to the coil negative. This should supply a voltage pulse that will drive both your tach and the EFI computer. Don't forget to disconnect the old ignition module by the fuse box. The gray wire... https://www.summitracing.com/parts/msd-6201/media/instructions

It has a title and it rolls. i bet he'd take $800 if somebody showed up at his door with a trailer. It would probably fit in a UHaul van.

If the vacuum hose to the vacuum canister leaks you won't get heat. The vacuum cark needs vacuum to expose the heater core.

Yes, the ZX distributor body has a spot to attach the miniaturized module directly to the side. The 280Z distributors run a long set of wires to a remote module in the cabin, by the fusebox. Your 280Z module is probably still working. But, it's old. But, it can be replaced with a GM HEI module. EuroDat even wrote up a procedure to make it look stock.

Put up a parts wanted ad. I know that I have passed a couple of good used 280Z distributors on to others. Classic Z people know what to look for and might have a used one that will be just fine for a reasonable price. You can even use a 240Z points distributor with an MSD or Crane module. But the MSD and Crane modules are still kind of spendy. 260Z is like a 280Z also, so there's an oddball you might look for too.

That's one option. I think that most of us just make the most of what we can find. You'll find stories of people returning multiple Cardone remans until they got one that worked. Reman world is rough. Here's a ZX distributor for $1000 -

None of that makes things more clear, does it?

You can run an MSD or Crane or other using the 280Z distributor as a trigger. You still want the advance mechanisms to work right. The GM HEI rev limit is an old and unfounded rumor stated by David Vizard many years ago, in Chevy world. GM has used the module in their cars for many many years. I dug in to it once, a while back. See below. Again though, the advance mechanisms need to be right. Pertronix has shifted to offshore manufacturing. There are questions about the quality of what you would buy today, versus the guys who have had one for ten years. And, advance mechanisms. It's a problem. Separate the advance control, vacuum and centrifugal, from the ignition module, in your thinking. If you get a good distributor, like a 280Z unit, with a good breaker plate, you can use it to do a lot of different things.

Give some specs. Is it a coupe or a 2+2? Automatic or manual? Download the Service Manual for reference, linked below. Surprising that it runs and drives, did you have some help getting it going? Usually the fuel system is pretty well buggered up, after ten years. Spokane is pretty dry though. https://www.classiczcars.com/files/category/13-280z/

With a solid valve train they say a noisy lifter is a happy lifter. You can set valve lash cold. The specs are in the earlier FSM's, like 1976.

That's a classic bad booster sign. If the engine is running a bit rich the idle speed will go up. Sounds like your engine is tuned about right so the idle speed drops. The boosters usually go bad when the master cylinder leaks. So watch out for brake fluid in the booster. It will drip on to your paint and stain it. Boosters are getting harder to find also.

Is the car factory stock or has it been modified/lowered? And does it have a turbo now or are you planning to add one? @turbo280z

In Chicago you have some pretty big temperature swings. Wouldn't be a surprise to find your gas tank rusted, due to condensation. Might even find some water in the oil pan. Carb float bowls probably dried out. Drain the oil and the fuel tank and you'll know a lot more about how much work is in front of you. Good luck.

Look at at 30, 31 and 32 here - http://www.carpartsmanual.com/datsun/Z-1969-1978/power-train/transmission-case/4-speed/from-sep-71

What happens if you connect the two wires? If it's a switch, then something should light up or buzz or something. I seem to recall also, that the "top gear" vacuum advance function was actually introduced before EFI. It's an emissions function and 73 was one of the first emissions vehicles. Might be a top gear switch.

He apparently, according to the words on the page, installed the 123 directly after having the engine apart. Must have had the oil pan off to check the rod bearings, and must have changed the water pump. So a fair bit of disassembly. Put it all back together, installed the 123, and cranked it up. Then smelled smoke on the drive and the engine was struggling to run. That sounds like overheating to me. Breaking the rings on a single cylinder will cause the engine to run rougher but it will just keep going easily on 5 cylinders. Might burn some oil but it will probably run okay, on 5 cylinders. Seems like he did a repair and an "upgrade" at the same time, had a problem and blamed the upgrade. But it might have been the repair. Overheating can lead to detonation. I wonder if he got it fixed and realized the true cause. Who knows.

Rill Cosby hasn't been back since December of 2019. I did notice another odd thing in his first post.

The parts look like 280Z parts if you compare to Rockauto pictures. If moozieman is 100% sure that it's the distributor then there's only one thing to do. Remove the distributor and check it out. The overall description doesn't really make sense anyway. Why would the rotor grinding on the cap cause the engine to die? The engine would happily just grind that cap and rotor in to dust.

What do you know about the engine? Why was it parked? You might get the engine spinning with starting fluid before spending on new carbs. Like site says though, clean things up first. Check your air passages, the intake manifold, etc. Squirt oil in the cylinders and let it soak for a while. Take the valve cover off and check the cam shaft. Spin the engine by hand and with the starter and no plugs to make sure it doesn't have a rod about to poke through the block. Basically, try to be sure the engine is worth spending money on. Then start spending.

I thought it was a heat shield.

Put your finger on the top of the shaft and see how much play there is. Wiggle it and see if it moves far enough to touch anything. Or just take the distributor out and see if there are any obvious problems. While it's out see if the drive quill (down in the hole) has problems. Your problem doesn't sound complicated but you're going have to go farther to solve it. It's an uncommon issue, nobody out here will have the easy fix. Time to take things apart. Removing the distributor is super easy. One screw, and disconnect the red and green wires, and it pulls right out. It only goes in one way, so you can't really mess things up. That distributor is so rusty inside that it's almost guaranteed that your vacuum advance doesn't work anyway.

Don't the push button style work by only partial thread engagement? Only at the button? Will it survive the stress of the puller? Guess you'll find out...

Doesn't really sound like a distributor problem.