Zed Head

There's a guy who just started a thread about a whole yard full of Z cars that he was helping somebody part out. Many of the pictures showed 4 barrel manifolds. I'd post a link but it's not in the last day's worth of activity and I can't find it. Search around. The title was something like "240Z, 260Z, 280Z parts", or something like that. There were a surprising number of 4 barrels. If we could just get an endless scroll of activity on a page to look through that would be so awesome. So much stuff disappears after a day. The old conversations are the reason people come back.

I don't think that the ignition module actually "flows" much current. It senses voltage but the current flow is probably more like what a capacitor might see, I'd guess.

BAT seems to be the go-to 240Z site these days. Have you been watching there? There's a member here who comments over there and might have made deals. Sccobyroo or scoobydoo or similar (edit - SCRAPPYDO is the guy). Can't remember who he is here. But he probably knows how deals get done over there. Seems reputable. http://bringatrailer.com/search/240z/

Oops. Stepped on Dave's lines... You can get spark testers also. I've never tried one but they make sense. Hard to see the spark sometimes if it's bright out.

That was interesting. I pulled down my 78 parts box and the old switch was right on top (meant to be!). I hooked up some leads so that I could easily turn the key and listen to my meter-beeper (I know CO doesn't like them but mine has a readout to watch also) and found that R had continuity with B right away and to the end of rotation, but S was iffy and seemed to only have one narrow range where it had continuity. Then I remembered that I had pulled it apart in the past when I had a problem with my 76, and had ended up bending the internal actuating rod to make it work right. Testing with the switch pulled apart and turning the electrical portion with a screwdriver showed that both S and R could be over-rated to where they lost continuity. The only thing controlling the total degrees of rotation is the mechanical (key) part of the switch So I'd guess that your new switch is just adjusted to turn the electrical switch too far. Not good news but it can be fixed, if you unstake it and take it apart. You can twist the flat rod with a pair of pliers. But I don't think it's right, it's a flaw in operation. One big "Ah Haa" from back when I used to start the 78 parts car is that now I know why it would start to turn over then let go all of a sudden, leaving the starter spinning loudly. I thought it was a starter problem but now realize that it was just the ignition switch rotating past the contact and losing the S circuit. I spent a lot of time trying to reason that problem out and never really had a good theory. Edit - more interesting stuff. I noticed that the brass male S pin was wobbly on the back of the switch. So I restaked it with a drift pin, put the whole assembly back together, and both S and R worked as expected, full continuity over the full Start rotation. So, check the pins on the back, maybe R is loose and can be reset with a little tap of a hammer.

So, to summarize - within the range of the Start position,which is essentially just off of the Run position, your switch completes the S circuit immediately and holds it, but loses the proper R circuit after a certain amount of rotation. Looks like 1978 still has an R but I can't find a diagram that shows it connected to anything. I'll dig mine out if I get out there.

All of that is correct. The nut is supposed to clamp the insert in to the strut tube. The sleeve keeps the insert centered. Your gland nut does look a little bit deep though. When you tighten it down are you sure that it is actually clamping the top of the insert? It might be bottoming out on the internal threads. Tighten it down with the shock/insert inside then grab the shaft of the shock and see if it can be moved side to side or up and down. You can put a washer on top to get more clamping if it's bottoming out on the internal threads.

Here's something that might be illuminating - what happens to the circuit to the starter solenoid when the power to the R terminal switches? If you don't get power to the starter solenoid then the R terminal is kind of irrelevant. Instead of looking at key position look at solenoid power.

"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?