Zed Head

"Loose" was a poor choice on my part. How about poorly or incorrectly assembled? The rotating mechanical parts are misaligned with the rotating electrical parts. So your basic question is "Are there supposed to be two electrical circuits possible in the one Start position of the switch?" Seems to me that if Nissan intended two circuit possibilities that they would show two circuits possible at Start in the wiring diagram. Anyway, might be fun to have a few people test their spare switches. I have a 78 280Z switch in the garage, but they stopped using the ballast in 78 so don't know if it would be the same.

You have the correlation or cause-effect conundrum. The loose wire might have been significant but not the cause of the problem. Intermittent problems are the hardest to solve, you have to be ready to test and diagnose right when they happen. When you say "spark" do you mean that you actually removed a plug wire and checked for spark? Or that the engine wouldn't fire? No spark could be the fairly common ignition module problem, no-fire could be wet plugs.

Not really clear (to me anyway) what you mean by "further against the detent spring". Are you saying that the Start position has two states? Start is at the end of the cycle so there shouldn't be another position beyond it. Sounds like a loose switch that is passing its contact point. Defective. Pretty sure that SteveJ has written about the differences in the Ignition switches, in the past. @SteveJ

You can build a simple plate with two holes in it to seal it. A test might be to remove it and leave it connected to the fuel hose, but disconnected from the electrical connection. Stick the nozzle in to a small jar or cup. Then remove the starter solenoid wire and turn the key to Start to pressurize the fuel system. If it's leaking you'll see it. You won't have to worry about intake vacuum with the starter disconnected, you'll only be testing the CSV when its pressurized.

I might go directly to the coolant temperature sensor circuit. The best way to test it is at the ECU connector, since what the ECU sees is what matters. Compare the resistance measured to the value in the chart. If it's too high you'll get too much fuel. This book has tests for all models up to 1980 -

I think we're just a little miffed to be the last resort instead of the first. You probably spent a lot of money that you didn't need to. And sometimes old Nissan parts are better than new aftermarket parts. As far as measuring things, people do it all the time without realizing it. If the engine dies you measure the fuel level by looking at the gauge, if it starts running weird you measure coolant temperature by looking at the gauge, voltmeter, oil pressure, etc. A multimeter is just a way to get a little bit more valuable information. It's just another gauge.

I was thinking about the instrument lights. The 240Z wiring isn't quite the same as 280Z wiring though. Not sure how they did turn signals, or instrument lights for the 240Z. But the switch pitting and wearing, causing overheating, is just a design weakness that they carried all the way through the Z car years. Edit - most of the switches in my car worked more consistently after I sprayed CAIG Deoxit in to the internals and worked the switch. The inherently moist Z car interior isn't good for the switches. How is the dimmer switch for your headlights doing? Mine didn't work until I Deoxit'ed it. Bummer that you tore the whole interior out only to find that damaged switch on top of the steering column.

The wire breaking off at the solder joint is fairly common, I think. Not unknown anyway. My headlights wire did that. I ended up running the running lights and the headlights through relays to take the heat out of that switch. The cause for that, as I've seen it discussed is that the contacts get pitted and carboned up and get hot, hot enough to either melt that solder or cause it to fatigue after many heat cycles. Better check your tail lights. They share power with the instrument lights. No instrument lights means no tail lights on my 76 car. The fuse is probably blown. Looks like two problems, one is the overheating switch, and the other is the blown tail lights. The current from the shorted tail lights might have pushed the switch over the top before the fuse blew.

You probably solved the real problem by trying to solve one that doesn't exist. You supplied power to the coil through the pump power circuit. Didn't read back through your thread but you need to take measurements with a meter or use a test light, to know what's happening.

Ya gotta measure stuff. Fuel pressure, coolant sensor resistance, etc. If all of the measurements are right, another possibility is a bad ECU. People have temporarily fixed them by knocking on the side or wiggling the connector. You'll want to take your measurements at the ECU connector so that act alone might solve your problem. You can test site's suggestion by removing the black cover on the side of the AFM and watching the weight while it runs.

Not sure but I think that he was saying that the coil driver wasn't "triggering" or being driven by the VR signal. It's not damaged. But not really clear why it worked once with the same low voltage pulses.

I'm thinking that Elite Auto is just using eBay for free advertising. Their name and web site address is in the picture. Probably no real intention of selling the car on eBay.

I guess you never know. I had a wood chipper that wouldn't start with one year old fuel. EuroDat got a 1/2 tank full of water in a car he was actively driving. Roll the dice!!!

If you have two out of round tires and their wobbles get sync'ed up you'll get a really bad wobble. A jack and 16 lug nuts is pretty simple. But all of that other stuff is fun work anyway. Except for the risk of creating new problems. Not really many new problems that you can create by swapping wheels. Just my keep it simple approach. Carry on. At least you're trying one thing at a time so you'll know what the cause was when you're done. I can't stand the shotgun approach, with no answer at the end.

Nobody is going to make you an offer on that tiny bit of information. Need more info. Pictures would be good. https://www.hagerty.com/apps/valuationtools/1984-Datsun-300ZX

If you didn't have the problem before then 98% of what you're doing and planning has no real basis. No offense. I would focus on the tires. I had a tiny wobble on my other car that slowly grew in to a bigger wobble that I knew was tires but I waited too long to fix. Had a blowout on the highway at 70 that probably started out as a busted belt in the tire. The blowout ended up as a softball sized hole in the tread with frayed steel wire from the belts poking out. In the few seconds it went from wobble to blowout I thought a gang of bikers was passing me, I actually looked in my mirror for the choppers. Just an aside... Try swapping your back tires for the fronts. If it's bad front tires you'll notice a difference.

Is there supposed to be a picture attached?

Here's a car that "people also viewed" from the 105 page. Somebody values their work highly.- http://www.ebay.com/itm/1972-Datsun-240z/112437184911?_trksid=p2047675.c100010.m2109&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D44732%26meid%3D7928fd31efa84d09bd18a0c7fdc6a641%26pid%3D100010%26rk%3D6%26rkt%3D6%26sd%3D292151078816 Edit - if the engine is not in stock form, is it still a concours restoration? Concours restomod maybe?

The basic fuel pump test is to remove the small yellow wire from the starter solenoid and turn the key to Start. That should provide power to the fuel pump. With the engine not spinning noisily the pump is easy to hear. You'll probably hear the pump relay click also. The EFI systems are a collections of sub-systems. Each needs to be checked for function. It looks complex but if you just start running through each you'll be done pretty quick. They're not like the old carb'ed muscle cars, where you just need power to the coil and a screwdriver at the starter. All of the electrical stuff tends to get a little bit of corrosion that causes problems. The headlight switch, turn signals, maybe the Hazard switch, horn, various relays. But there's probably a thread about each one in here somewhere. Almost all people new to the 280Z EFI try to jump ahead but in the end we all had to work through the electrical systems, one by one.

There's an old yellow 280Z under a broken down shed on Skyline Blvd. Still there. They'd be useful for whoever can break that car free. @Mark Maras

That is a cleaner, neater approach. Just don't let it run if it does start spinning. The car has been sitting for ten years though (2007, first post). So a person could argue that if he just wants to hear the engine run that he should probably plumb up a suction line to a clean can of gasoline and bypass the fuel tank completely. The odds of 2007 gasoline being run-worthy are super-slim. I don't see any mention of new gas or new parts. Getting even more basic, if one of us was looking at this car the first thing we'd probably do is pop the gas cap and smell the filler hole. "Eeeewww,..that's not going to work" is my guess.

I would do what site says but also disconnect the hose before the fuel filter, in the engine bay away from any sparks, and catch what comes out in a 2 liter bottle or gas can. Check the quality before you pump it through your filter and fuel rail. If it smells sickly sweet and is orange let the pump drain your tank and refill with fresh fuel. Also, read up on the fuel pump contact switch in the AFM. It's a simple check of the power circuit for the pump. Open the vane.

He's selling another Z too. Same phone number. I love and hate the internet. http://www.autoquid.com/car-detail/z-series/1972-Datsun-Z-Series-1972-Datsun-240Z_292140781007.html

I almost wrote earlier about 105 seeming familiar and maybe being associated with the Harmony guy who posts but never sells. Pumping up the values. Can't find it on the site though, maybe somebody's memory will find it.. Google "HLS30-000105" without the dash and a bunch of other stuff comes up. Google extracts data and posts it on the search results page that can't even be seen when you click the link. Like a leaky NSA. Joel Harmon, car is in Las Vega, Nevada. Edit - I see that this in the eBay ad too. "(702)-460-7122 it is located in Las Vegas Nevada 89115." https://www.google.com/search?q=HLS3000105&oq=HLS3000105&aqs=chrome..69i57&sourceid=chrome&ie=UTF-8 http://cars.oodle.com/detail/1970-datsun-240z-series-1/4578497274-las-vegas-nv/ http://www.buyautoshere.info/292151078816.html

My mistake. They put the vinyl on pretty tight on the early cars. My 76 is loose and puffy. My 76 has gray primer. Did Nissan use red primer for the early cars? Just adding to the puzzle. Edit - is that a factory green color? Seems kind of bright. Edit 2 - there's overspray on the serial number badge. Edit 3 - two tone seats. Not stock, or an early option? Yellow sway bar. That's the thing about barn finds. They're time capsuley. Restoring removes all that.