FastWoman

Hey Chad, I know the '78 has a large intake screen in the tank, probably about the size of a small coffee can lid. I don't know about the '76. If you didn't see tons of debris in your tank and didn't try coating the tank with epoxy, the screen should be fine. Some people acid wash the tank and then coat it with epoxy. (Because the acid wash would eat out the screen, there's probably nothing left to clog with the epoxy.) I suspect the coolant temp sensor is a more likely cause for your problems. Keep in mind it might not be the sensor, but rather the connector it's plugged into. This connector sits at the front of the engine and gets REALLY dirty, crusty and brittle. If you were to unplug the sensor, your engine would be choking in fuel and blowing black smoke, if running at all. BTW, 280, teflon on the EFI's coolant temp sensor wouldn't affect functioning, as it doesn't use the body as a ground. However, the temp sensor that feeds the instrument panel (that has a 1-wire connector), does use the body for ground, so I suppose teflon tape would be a bad idea (although electrical contact would probably be made anyway, depite the tape).

I'm totally lost in this thread, but I can help you with the vacuum hoses. These control your heating/AC system. 1 supplies vacuum to the system, running to the check valve, magnetic vacuum switches and vacuum reservoir on the opposite side of the engine compartment. Those feed a like that goes through the firewall to supply the mode control vacuum switch (off/vent/ac/heat/def/etc). They also feed a line that comes back to #2, which pulls up the idle when the AC compressor is running.

Argneist, I'm wondering whether your #6 injector is injecting. You might have a bad connection. #'s 1-3 look lean. #'s 4 and 5 look really rich. I'm also wondering whether you have connectivity issues with your injectors or drop resistors. And of course you might have significant valve adjustment issues. Perhaps Cylinders 1-3 are drawing a lot more air than cylinders 4 and 5. (All cylinders supposedly get the same amount of fuel, assuming the injectors fire.) What are your compression numbers, again???

Here's a pretty good annotated slide show... http://www.picturetrail.com/gallery/view?p=999&gid=1803105&uid=786489

Be sure to pick up a set of insulators and O-rings for your injectors!

FAIW, I've turned those stupid idle mix screws back and forth, with apparently no effect. I'd be very interested to see what sort of effect that adjustment has on the exhaust readings! I'll stay tuned.

Rob, that instant happiness thing might well be worth $350! There's someone else on this forum who is suffering with a wiring mess that used to be a working harness before some kid got hold of it.

Hi Argneist, It sounds like you're getting to the point where I was a while back. You've done a LOT of work and your engine still isn't right. Cozye got to a similar point, and we sort of worked through a common solution together. It turns out that our ECUs had drifted in their timing properties over the decades, and so we had to trick them about coolant temperature in order to correct their timing. You can read all about it in this very long and meandering thread: http://www.classiczcars.com/forums/showthread.php?40234-Purs-like-a-kitten...&highlight= Somewhere buried in there is my "yogurt cup test," whereby you remove the AFM, stuff a yogurt cup into the AFM/throttle boot, place a hose on the vacuum booster nipple, and blow on the hose with your mouth to "inflate" the entire intake system. A bit of air will leak out, but if the intake is tight, it won't be much. It's a very quick way to confirm that you've found all your vacuum leaks (rather than searching endlessly for a leak that might or might not be there). Once you've put the vacuum leak issue to bed, you can move on to other issues. Anyway my engine wasn't running quite as badly as yours (judging from vacuum numbers -- mine being maybe 14 in Hg initially), but I was able to get my engine running quite well by adding resistance to the coolant temp sensor circuit (thereby correcting mixture). I now run with about 18.5 in Hg. Cold and warm running are quite good. I think I'm just a tad on the rich side, but better rich than lean. (I can adjust the mix leaner with the turn of a screw if I want.) My engine almost always starts in less than a second (1 revolution?) and runs strongly. The only exception is if it's been running and sits for about 20 min, during which time it becomes heat soaked and might take a few revolutions to start. Mileage is about 19 or 20 combined, and more towards the upper 20's on the highway. The magic that made all this happen is a little resistor in series with my coolant temp sensor. :-) Anyway, study the thread I linked, and you'll see how Cozye and I systematically went through all this stuff. (He achieved similar results, BTW.) Oh, and don't worry about the valve adjustment. It's a very easy and strangely satisfying undertaking. You'll be working on the most beautiful part of the engine, IMO. Just don't get your hopes up that it will awaken the beast in your engine. It probably won't make a huge difference, but it definitely needs doing from time to time. Enjoy!

FAIW, I firmly believe that the value of almost any "ordinary" collector car (i.e. not some rare limited edition car, extremely low VIN car, historically important car, etc.) is based mostly on the effort and cost usually necessary to restore a car to that condition, coupled with the willingness of someone to dump that sort of time and money into the car. A rough 1964 1/2 Mustang fastback might be worth $1000. A rough 1970 240Z might also be worth $1000. Restored as nice DD cars, both might be worth $8-12k. Frame-up, show-condition cars might be worth much more. These nicer cars demand these sorts of values mostly because they cost that much to put in that sort of condition, not because there are a bunch of enthusiasts somewhere rah-rah'ing their cars in multiple orgasms. I also own a Miata and am active on a Miata list. Miata owners drool over Miatas even more than Z owners drool over Zs. While Z owners freely admit there are a few shortcomings in the Z design (e.g. in the charging system), Miata owners are steadfastly incapable of realizing there are any shortcomings in the Miata design (e.g. some very badly designed hydraulic lifters, a problematic cam angle sensor O-ring, a really fragile heater core, etc.). To them, the Miata is the PERFECT car. So why aren't Miatas more valuable than Zs? Miatas seem to cost maybe 1/3 what Zs do in parts, and they're not old enough yet that they require much work to put them in top condition, so not surprisingly, pristine NA Miatas will sell for maybe half to a third of what pristine Zs sell for. Wait until the parts get rare and the bodies get rustier, and the gap will close. Believe me, if value were only driven by enthusiasm, Miatas would be commanding enormous prices. In the end, are Z cars undervalued? Maybe just a bit, but maybe not by much. We like to feel slighted when we compare the value of our cars to the great American Muscle cars of the 60's, but honestly we're comparing two different decades. How many 1970's muscle cars sell for what the 1960's muscle cars do? What do you think a 70's turbo Trans Am (hailed by many at the time to be the epitome of American Muscle) would sell for in fine shape? Have patience, and our cars will command the better prices too. I don't think there's any disrespect of Japanese collector cars. I just think the Japanese cars didn't come into their own until the 70's. It's not yet time for them to be extremely valuable. And to be perfectly clear, I never said the perfect 240 isn't worth $38k. I was merely joking about anyone who has that sort of money to throw around in these very challenging economic times. I know I wish *I* had that kind of money to throw at such frivolities, but my frivolity budget is much more modest.

WOW! You've about covered it all. OK, did you check your throttle position switch? You might be getting full throttle enrichment all the time. How's your fuel pressure? (Yes, I know you checked your FPR for blockages, but did you measure pressure?) If it's too high, you'll be injecting too much fuel. Another potential problem would be that your AFM's main spring is too loose, perhaps because someone tampered with it. Atlantic Z has an article about adjusting the spring to alter the fuel/air mix. I doubt poor atomization by your injectors would be to blame, but it probably couldn't hurt to change them. Do you think they might be sticking open from varnish? (Do any of the plugs foul more than any others?) You might run some Chemtool B12 in your gas to dissolve any deposits. If all else fails, you might try tricking your ECU into cutting your fuel back a bit. Just like some of us run a resistor in series with the coolant temp sensor to enrichen the mix, you might try running some resistance in parallel with it to lean the mix. I wouldn't do this until you've ruled out the above, though. Good luck! And welcome!

Stuff is spliced everywhere?! Oi! I once bought a car like that. In hindsight I might have been better off with a new wiring harness. Fortunately it wasn't a car I really cared about, and I sold it after it served its purpose.

bhermes, you should only post your question once (in a thread that you start, not on the end of someone else's thread about something else). I'm not fussing, but just saying. Here's the other thread under the "help" section: http://www.classiczcars.com/forums/showthread.php?41946-Multiple-problems-1st-time-owner. FAIW, this is a somewhat low-traffic list by comparison to some. You won't get instant responses, but you'll get good ones -- less noise, more quality content. We all sort of know each other too, in an internet sort of way -- and often in person. There's also HybridZ, which has a lot more traffic. It's all about mods -- mostly engine mods -- to these Z cars. It's a much more high-key list. This list is more for the folks who get excited about these cars in their stock form!

E, I'm not saying it's not an amazing car! I hope someone clicks that "buy it now" button. Too rich for my blood, though.

Touch a small wire from the battery (+) terminal to the little spade connector on the starter's solenoid. If the starter springs to life, the problem is somewhere in your ignition switch wiring, and not in either the battery or starter. If so, it could be a bad fusible link.

First, WELCOME and congratulations! You'll love your "new" car, once you get it straightened out! Let's see... Dash lights: NONE of them are working? Probably a bad/dirty rheostat. Clean with contact cleaner. Also clean your fuse block with contact cleaner. You can't find the original panel bulbs, but you can replace them with Eizo A-72 bulbs... http://bulbster.com/lightbulbs/eiko-a72-48002-p-3002.html Brake light staying on: There used to be a little rubber plug in a hole in your brake pedal arm, just underneath the brake light switch. It's rotted and fallen out. Substitute a bolt. Smooth the head, and apply a tiny bit of grease to it. Not familiar with the "voltage light." Can you elaborate? Squealing brakes: Might need to turn the rotors, but sometimes you can just roughen them up with a very coarse grit of sandpaper. You can also try washing down the rotors and pads with brake cleaner. Small gas leak: Honestly, I'd recommend you pull your tank and fuel/air separator, clean out the tank, check all the fittings, and replace all the hoses. There are many threads on it. Click on the magnifying glass at the upper right (search) to search for those threads. It's a nice, not too difficult little project. Be sure to use all fuel-rated hoses, including the large 5/8" diameter vent hoses. You can get those from a tractor supply company. General advice: You should definitely get a factory service manual for your car (the Datsun publication). If you search only a short while, you'll find out where to download a copy for free. However, I prefer the paper copy, which can be found from time to time on Ebay or Amazon. Each year is different, so get the right year. Eric (Cozye) is a fellow Kentuckian, although I don't know where in KY he lives. You might give him a shout. He knows quite a lot about the EFI 280Z engines and does some very impressive body work. Again, welcome!

Nice! But contrary to the seller's claims, there's a touch of rust in the hatch area. I'll pass.

Oh, I didn't get that part -- engine previously running with tach plugged in. Hmmmmm.... Are you sure your tach is wired correctly? Is there any part of the tach's wiring that you worked on? I'm sorry I can't be of much help here, as the 260's tach circuit is wired differently than my 280's, which is electronic.

You also can't mix Freeze 12 with R12. To go from one to the other, I believe you have to evacuate the system first, but research whether there's anything else you need to do too. FAIW, we did a cheap 134a conversion on a GM R12 system (changing a few fittings), and it worked pretty badly, ultimately blowing up in an impressive display of spraying freon. I wouldn't recommend it, especially in a place as hot as Houston.

By the pigtails, I mean the little hoses. As I recall they're about an inch too short. What you have to do is CAREFULLY slit the rubber around the injector barbs, cutting at an angle that would just graze the soft aluminum barb, not scratch it (or else you'll have a leak). You should actually only cut deeply enough to slice through the cloth reinforcement, but not through the inner layer of hose. Then you can peel the hose off of the barb and out of the little end-cup/cap that's used to secure it. You can put on another fuel-injection rated hose with a regular clamp around the barb. The cup/cap thingie is an alternative to a clamp. The hose butts into it, and it keeps the hose from backing off. The barb has pretty aggressive ridges to grip the rubber. I suppose you could reuse the cup/cap, as it's not damaged during removal, but I just trust a clamp more than I trust that little thing. BTW, I'd pick up the Comp Cam clamps from Summit Racing -- the ones with the smooth inner surfaces that don't eat into the hoses. You can pick up larger clamps of that variety from Hampton Rubber, but they don't have the smaller ones. Or at least they didn't when I was buying mine. Get the ones like these (but pick the right size): http://www.summitracing.com/parts/CCA-G3912/

Well, if you DO end up pulling the full cap off, you might consider replacing with a half cap if it will do the job. The instruments are still removable with a half cap, but it's a squeeze! But yes, others have dealt with this same issue. You should be getting some advice pretty soon.

^^ What Grant said. I didn't learn the hard way, but I did find this was the case. It's not difficult to do.

Oops... double post

Ben, you can look at insurance the way I do. It's not a money saving thing on the part of the insured. Risks are carefully computed and entered into actuarial tables, and a premium is charged very comfortably in excess of expected claims. So if you can afford the loss of your car (not saying that you won't be sobbing like the speaker of the house), you're probably better off without collision coverage. I carry liability and comprehensive (not at all expensive -- covers things like vandalism, but might not cover me for my concept of what my car is worth), but I leave collision to the goddess of stochasm. I'm a careful driver, live in the country, don't subject my car to known risks (e.g. rush hour traffic), and don't log that many miles per year anyway, so my risks probably aren't even as high as would be reflected in the actuarial tables. If I wreck my car, I'll have zero grief with a claims adjuster and can repair my car as I see fit -- or not. Meanwhile, I'll have probably saved enough money on insurance premiums to cover the repairs.

The tach is probably shorted and shorts the (-) post of the ignition to ground, ergo no spark.

Aside from snow/salt, why don't y'all drive your Z cars year-round? OK, I admit I do have a rule during the winter that I don't drive any car I care about after the roads have been salted and until the first good rainfall thereafter (to wash the stuff away). Gawd, with climate change, we sometimes have snow after snow here in Virginia, so sometimes my poor Z has to sit there for as long as a month before I can drive it. But I do... even in the cold.