NewZed

I think that carb is too big for the engine. The typical carb is the 390 CFM Holley. Might be better off to get the right size and tune it for the engine. Might save you a lot of time.

One of the first thing many people would do with a problem like yours is to measure fuel pressure while the problem is happening. There are many threads describing having a fuel pressure gauge attached while driving. Proper fuel pressure is critical to proper operation for any fuel injection system. It affects how much fuel is injected. You could save a lot of money by more reading. The injectors aren't going to stop working while driving then fix themselves when things cool down. Neither is the AFM. Or the coolant temperature sensor. And the cold start valve is just another injector that only gets power when the starter is engaged and the engine is cold. You've narrowed the problem down to parts that you haven't replaced, not potential causes. Odds are high that it's your fuel pump. A measurement would confirm a pressure problem. And your fuel pump should'r run when the key is on unless the engine is also running.

That's a lot of carburetor for an L24. http://www.edelbrock.com/automotive/mc/carburetors/performer.shtml http://www.edelbrock.com/automotive/misc/tech-center/?query=1405&submit=search The manual says no more than 6 psi - http://www.edelbrock.com/automotive/misc/tech-center/install/1000/1405_manual.pdf Could just be a bad needle and seat or a sunk float.

That's not why you said you were removing the head. I went with what you wrote. Work on your writing skills. The last two statements are ironic. Brand of timing chain set would be a little detail, considering the scope of your project. You got three answers already anyway.

Why take the head off to fix the threads of some valve cover bolt holes? Makes no sense.

Not quite. You'll be moving the module away from the distributor. For the ZX the two wires from the VR are connected internally, behind the module, where you don't see them. They're still red and green though. Just connect red to red and green to green and make sure that the module is grounded. Grounding of the module body is key, that's where the coil current goes.

You'll do a lot of work for not much benefit. Probably seemed like a good idea and worth doing once, but most people seem to end up with problems. Here's one. Notice that the "benefits" are reliability and removal of the AFM restriction. A stock 280Z EFI system is reliable though, and the AFM is not the big restriction on an NA engine. http://forums.hybridz.org/topic/49087-z31300zx-ecumaf-to-280zxt-swap-guide-1981-supplement/

There are always mounting issues. There's a good thread on another forum by a guy who mounted an HEI module inside the box that the original 280Z module was in. All of the wires are already there and it's protected from the elements. You could do the same with the ZX module.

Yes it is, Two wires to the VR, two wires to the coil, and a good ground circuit.. Not sure what you mean with the "mounting issues". A GM HEI module would be the same amount of work though.

Focus on function and specifications. The 6BTM outputs a 12 volt square wave (open MSD6 BTM instructions below), designed to run tachometers or other "RPM-activated devices". Make sure that Pin 24 is okay to use a 12 volt square wave and you're probably fine. There are many ways to get the same thing done. The guy who wrote the instructions above was using an HEI module so didn't need the tach output from the MSD unit. He probably could have used it though and been fine. He "over-commented" when he said that the yellow wire was "tachometer only". Megasquirt is not plug and play. Some electronics odds and ends knowledge is required. It's easy to get lost if you don't have some background. http://www.msdignition.com/Products/Ignitions/Street/Strip/Analog/6462_-_MSD_6-BTM_Boost_Timing_Master.aspx

These articles probably contain enough to get it done. Think in terms of function, rather than wires and wire colors and you can probably figure it out. Many cars use the same types of ignition systems, throttle body switches, etc. so the knowledge translates. If you use a distributor it's even simpler. Just get a proper signal from the coil to the MS ECU. http://www.diyautotune.com/tech_articles/megasquirt_install_writeups.htm

Could be the ignition module. They get hot and go bad, cool down and fix themselves. You didn't say when or why you replaced all of those parts so no way to make a cause-effect assumption. I copied the other stuff just for the amusement.

The guy who knows already said yes. We all can see all of the threads, no need to keep asking the same question everywhere.

There are "bump stops" on the strut shock shaft. If the car is lowered and the shocks toasted, "slamming" could happen. The front struts have a bearing inside the insulator so the strut can twist. The rears don't. Here's some pictures and names - http://www.carpartsmanual.com/datsuns30/DatsunZIndex/Axle/FrontSuspension/tabid/1729/Default.aspx http://www.carpartsmanual.com/datsuns30/DatsunZIndex/Axle/RearSuspension/tabid/1731/Default.aspx

Windows Media Player on Windows 7 too. Upside down. No option to flip. Quicktime plays it correctly. Looks like one of those Apple versus Microsoft battles. https://www.apple.com/quicktime/download/

If you don't know how to find a short you need to find some help. Replacing more parts isn't going to get it done. It may not be a short but that's one of the simplest electrical problems to diagnose. It could just be something always on and killing your battery. If that's the case, you'll get a spark when you reconnect the battery and everything is supposed to be off.

Looks like a bad alternator. Even though you replaced it. The need for a jump with a new battery suggests a short, killing the battery, then when you jump it, the load from charging the dead battery, or the short, or both, kills the alternator again. I would first verify no short circuits.

You could use cgsheen's friend from post #8. Odds are good that he knows what he's doing. I would have verified the timing, at least, before even coming back here. Then you would at least know a little more about the guy you took it to. Timing numbers are on a sticker under the hood, and/or in the FSM Engine Tuneup chapter. If you don't feel comfortable working on engines, cgsheen's guy is probably your best shot. You're not far off, but it's the little things like cleaning connections, turning the idle air bypass screw in the AFM, checking for vacuum leaks, etc. that will get you the "pass". If you don't enjoy fine-tuning, probably best to take it to the right guy.

Have you checked for spark? Could be no tach signal because there's no coil charge/discharge. Your 260Z should have electronic ignition with a variable reluctor distributor. Has it ever run?

It says "VISCOUS LSD" on the orange sticker. And it's obviously a short nose. Looks like cheap on the cheap. I think that later 300ZX's, like 1990 on, came with short noses. Still a common, inexpensive diff that is not a bolt-in for a Z.

I gave you the wrong link but it looks like you found the right section anyway. This chapter is what you want though - http://www.nicoclub.com/FSM/260z/1974/EE%20Engine%20Electrical.pdf

Thanks for that. The one thing that pops right out is no zinc additive for the cam break-in. Is that correct? I've never used a zinc additive on my old already broken-in engines and never had a problem. But the need for zinc during the first few thousand (million?) revolutions of raw steel on raw steel seems to be clear.

The batter(y) goes to the alternator and the alternator goes to the wiring harness which goes to the black cylinder which is the ignitor correct? - No, this is wrong, in many ways. Too many black cylinders in the engine bay to really know which one you're talking about. The black cylinder is probably your coil. The other stuff doesn't make any sense since you keep talking about an "ignitor" and your 260Z shouldn't have one. You're going to have to find a full-size computer and open up the FSM if you want to make any progress. The phone screen isn't going to get it done. There are drawings of the coil, so you'll know what that black cylinder is. At least put the phone to good use and take a picture.

Too many pages for me but maybe somebody could summarize the five setups. Rockers arms, cam brand and type (new or regrind), break-in oil, etc. The stuff that matters. They're not all the same type of rocker arms and cam are they?

Looks rich. You haven't added any details on the engine settings. " I've retarded the timing, messed with the afm, changed sparkplugs, adjusted the air bypass, and a couple of other things. " The statement above doesn't tell anyone anything. Numbers matter. Put everything back to stock including timing, Initial timing is important for idle. Verify that your timing advance mechanisms work. Advance is important for the load test. Measure timing with a light, not by ear or butt dyno. There are other tuning tips for passing emissions tests. But you need a good starting point. You didn't say if you get any retests or if you'll be testing at a shop before you go back to the state.