FastWoman

Here's the silver lining, though, and I don't understand why more people don't see it this way: The 260 is every bit as much car as the 240 or 280. It just doesn't get the love. So you can buy a really nice 260 (if you can find one) for less than a 240 or 280. And while it's true you won't have as valuable a car, is that something you really want/need? What if I told you I'd sell you an Acme GTO -- an exact clone of a Ferrari 250GTO in every way, equal in quality -- for $1000. But it would only be worth $1000, and it wouldn't appreciate any faster than the Ferrari. Maybe a decade from now you could sell it for $1500. Would you be interested in owning it? I would. There's a reason I sold my perfect '66 Mustang and drive a less than perfect 280. It's cheaper fun. In fact the Mustang was valuable enough as to have lost all its fun.

It's very simple to find out. Just pull off the black plastic cover. You'll find blobs of glue and caulk that mark the factory settings. If they've been disturbed, you'll be able to see it. You'll also be able to tweak the mechanism with your finger to see if you're running lean or rich. It's no big deal reattaching the cover. You just need a thin bead of caulk in the groove. You can hold the cover on temporarily with rubber bands or small bungie cords (or maybe tape?) until you're finished diagnosing/fixing/tweaking the system.

Yeah, it's the middle child. I don't think it's any less noteworthy than a 240 or 280, but rather that it doesn't get noticed because there are so few of them. Dunno.

Brian, SORRY ABOUT THAT! I just mentally grouped you as "down under" and didn't re-check before posting. I do realize NZ is a different land -- with a government that I very much admire, BTW. I believe Lord of the Rings was filmed there. VERY pretty place. I hope to visit someday, but it's a VERY long and expensive journey. Robftw, there's no reason to speculate on ring wear. Just do dry and wet compression tests. You'll have your answer very quickly. I don't think valve adjustment issues could result in oil in your intake.

Oh, getting back to Eric's question about remaining vacuum leaks, have you done the "yogurt cup test" (aHEM!... intake/crankcase leakdown test) yet? Oddly, you can have a vacuum leak and still have a high vacuum, as long as the resulting mixture is correct. In that case if you were to fix the leak, the mixture would be too rich, and engine vacuum would actually be lower (after you opened up the throttle plate a bit to compensate for the drop in RPM, of course). All the vacuum reflects is engine running efficiency, although a leak will certainly throw your mixture off.

Eric, if his non-running pressure is really 40, the fuel pressure will always be too high, irrespective of engine vacuum. However, depending on what his engine wants (and if he has yet another lean-running condition that seems to be so common), that might not actually be a problem. FAIW, the conversion between psi and in Hg is very close to 1:2. So it would take approx. 20" vacuum to drop the fuel pressure from 40 to 30 psi. (His gauges are a bit inconsistant, perhaps.) If he's getting 34 psi at 14" vacuum, that would correspond to 41 psi with no vacuum. An additional 4" vacuum (total 18" vacuum) would give him a pressure of 32 psi, when he should really be getting more like 36.3 - 8.8 = 27.5 psi. Again, it's not a problem if the engine has a lean-running condition anyway. Fixing the problem would make the engine run leaner/worse.

^^^ What the snail said! Nissan describes the reversal of gas movement in the FSM's section on the PCV system (EC section). Under load, the PCV system doesn't suck up all the blow-by, and so it blows back out from the valve cover to the intake boot. Under low throttle and high vacuum, fresh air goes from the intake boot into the valve cover, down through the engine, and out the PCV valve into the intake manifold.

I assume Arizona dust gets everywhere almost as badly as West Texas dust. I'd definitely go with a paper filter.

Well, your fuel pressure does seem a bit high, but as you say it could be inaccuracy in the gauge. If it's really high, the effect would be to richen your mixture. It would be good to have a static fuel pressure reading, just to be certain your pump is 100%. You can do this by plugging the return line. Alternately, you can just pull your supply line off of the fuel rail and connect it to the gauge. The only mixture adjustment on an unmodified EFI system is the idle mixture screw just below the outlet of the AFM. In theory, you screw it in (clockwise) to richen the idle mix. In practice the adjustment doesn't do much at all, at least on my engine. You can seek out some useful articles on the Atlantic Z website (google it) that discuss adjustments to the AFM. This is one approach to adjusting the fuel/air ratio. The other approach is to add a potentiometer (maybe 5 or 10 kOhms) in series with the coolant temp sensor. This is only useful if you want to richen the mixture. You could also add resistance in parallel to the CTS to lean out the mixture, but none of us have tried that yet -- haven't had to. Don't worry too much about messing with the AFM. If you're careful about what you're doing, you won't mess anything up. Just be sure to mark all your positions before moving/adjusting anything, so that you can return back to factory settings. (You may find that your AFM has already been violated -- broken glue blobs.) You can get into the potentiometer housing by prying off that black plastic cover on the side. It's very easy to tell whether your mix is too lean or too rich by gently tweaking the vane with your finger to find the fastest idle. CW leans out the mix, and CCW richens it. By doing this, you'll get a pretty good preview of how your engine can run with the correct mixture, and you'll also confirm which direction your mix needs to go (richer or leaner).

The thing on the throttle body (with electrical tape residue) is a dashpot, used to slow the return of the throttle. It's not necessary, but it does help. Contrary to appearances, nothing connects to the crumbly plastic cap. The translucent bottle in the next picture is a vacuum reservoir for the HVAC system. The vacuum is used to control the high idle on the engine and the various doors and workings in the air handler. Yeah, stock on the suspension -- with nonstock paint. Those vents are one of the "cooler" (no play on words) parts of the car, and yet I forget to use/enjoy them. BTW, there's no reason to be clueless about these things. You can download a copy of Nissan's Factory Service Manual at: www.xenons30.com You can also buy a paper copy used on Ebay or Amazon from time to time. Good book -- well worth the money.

Probably. The way the assembly fits into the car body, there's probably little or no chance of any sort of leakage. If you're still worried about it, you could always use a thin bead of silicone caulk. That shouldn't hurt your paint.

Eric, I haven't done the full seal replacement, but I've R&R'ed one of my quarter windows. There was no adhesive between that lower strip and the paint -- or on the paint anywhere, for that matter. Everything was just screwed in place. No leaks or issues.

... to which you replied, "No, it's normally aspirated."

Ah, com'on, Tomo!

Thanks! And you're welcome!

It's good that the problem is resolved. Here's a suggestion, though, somewhat related to this thread... kinda... Use an electric fuel pump with a kill switch on it. That will allow you to... -- starve the carbs when you're going to let the car sit for a week or more, so that the ethanol gas won't take its toll. -- prime the carbs prior to starting the engine. -- prevent theft of your car when the fuel pump switch is turned off (best done if the carbs are starved first).

It COULD be the relay. You'll find it inside that black box attached to the passenger-side inner fender. It could also be a bad contact in one of the big wiring harness connectors just inside the passenger-side firewall. As I recall, it's a blue/green wire in the corner of one of them. Mine had become hopelessly crusty and melted, so I broke it out of the connector and connected it with a bullet connector. Note that your fuel pump won't run any longer than 5 sec when you turn the key to START. Beyond that, it won't run again until the engine is actually running and has either oil pressure or voltage. In the '78, there's no longer any fuel pump shutoff switch in the airflow meter. Failure for the pump to operate could be attributable to the oil pressure switch AND alternator output. (Both would have to fail.) I see you're new. You can download your own FREE copy of the Nissan Factory Service Manual here: http://www.xenons30.com/reference.html It's a very good manual and will be invaluable for tracing stuff like this. A paper copy is even better. You can pick those up used on Ebay or Amazon from time to time.

Tomo, your arteries can't be THAT hard! As a former professor, *I* should be the language prude here! Slang has been with us forever and will be with us forever more. In my generation, the words of choice were "cool" and "neat." "Groovy" was on the decline, and "swell" had long since left the house. Doesn't bother me a bit. Even incomplete sentences. At least for informal writing. Of course if you hand me a paper, I expect formal grammar, spelling, usage, and punctuation. However, if you're addressing me on the street, y'all can tell me my car is "sick" anytime. 23 skidoo, y'all!

It's not the word itself, but how it's used, Tomo! For instance, "that's one BAD machine" is quite a compliment -- or not -- depending on who says it.

Wow, great pic, and great story! I remember in Texas there was a stately Rolls Royce Silver Ghost permanently parked beneath the canopy of the historic Stagecoach Inn that always seemed to fascinate me. But the Z makes a better mascot for Zanzabar!

Steve and 5th, that's not bad at all! I generally bristle at these sorts of discussions, because by engaging in them, we're only telling thieves how to steal our cars. However, this is one solution a thief can know about and still not have a clue how to defeat, unless he knows exactly where the defeat device is hidden. Very nice!

WHICH S30? Electronic ignition, if it doesn't have it already. Modern fuel injection? (I'm watching the MegaSquirt folks with interest.) Later model alternator. Heftier alternator wiring. Headlight relays. Maxifuses to replace fusible links. Some sort of engine defeat, so some ne'er-do-well doesn't destroy your car.

Yeah, it brings a smile to my face, too, when some kid says my car is SO SICK! It doesn't matter that it's only got 160 hp under the hood. Its beauty is timeless, as you say. I'm reminded of an early Chris Craft speed boat I saw that was... er... SO SICK! Under the hatch, it had an engine from a WWI fighter. As I recall it was a V12 -- almost a flat 12 -- with enormous polished cylinders bolted separately onto the crank housing, and it was finished with the perfection of a Bugatti. It was clearly the "sickest" engine I've ever seen. It was HUGE, and it packed a wholloping 85 hp, as I recall. The power didn't really matter. It was a thing of beauty.

Steve, see the link in my post #7 above. Not a bad little gizmo. I think I'd pop for it just for the convenience and neatness factors, even though I could easily design/build the circuit myself.

No, my BCDD doesn't work anymore. I should just remove it. Many people remove the thing and just fashion a plate to cover the hole.