FastWoman

Well, I have a '78 280Z, the last model of the Z lineage. I'll assume yours is wired the same, although it might not be. Assuming it is... The fuel pump will energize for 5 sec when you turn the key to "start," and then it will click off, unless the engine is actually running. (I'm pretty sure I have that right.) The system knows the engine is running when either the alternator is putting out voltage, there's oil pressure, or both. These inputs feed to the fuel pump control relay, which is not the same as the fuel pump relay. The fuel pump control relay then actuates the fuel pump relay. Either or both of these relays could be clicking out on you. You might get some advice that there's a fuel pump shutoff switch in the AFM, but that wouldn't apply in the '78, and I'm almost certain the switch isn't even present in the ZX AFMs. (I have one as a spare part.) So I'd just start tracing signals -- oil sender, alternator fault signal, fuel pump control relay, fuel pump relay. You might have a bad connection, corroded wire, and/or faulty sender. Sorry, no quick/easy fixes. There's not anything that "usually" goes wrong up to the level of the relay. Beyond the relay I suspect there is a common corrosion problem in one connector, but it wouldn't cause your relays to click.

Yeah, I imagine it's crimp -- and it's quite lovely.

I think headers CAN be civilized. I say that only because my stock Saturn SL2 and my stock Miata NA both have headers and don't sound obnoxious, but I think they also have conventional baffle-type mufflers. On the other hand, when I pulled the PO's obnoxious headers off a '77 Suburban and put on manifolds, it made a WORLD of difference! OH, GOD, the beast was finally QUIET! So I guess it could go either way. Maybe you should seek out fellow Z owners with header systems and decide for yourself how their systems sound.

Oddly, even used parts suppliers might sell a ____ for a 1982 280Z or somesuch. You would think they would know better, being in the business. A bit less egregious, I'll often go to the parts store where they actually know me and know my car, and I'll ask them to look up a part for me, reminding them it's a '78 280Z. Half of the time, they'll enter a '78 Cheverolet Camaro Z28. The other day a woman my age saw my car and exclaimed, "Cool RX-7!"

All good advice. With regard to hoses, I'd just get the generic fuel-rated stuff, unless you want to be a purist about everything being all-original. There are a couple of formed, woven larger hoses (the 5/8 variety). The longer one has to make a couple of turns that are somewhat tight, hence the pre-formed bends. A non-purist solution to this is to get a couple of 5/8" Goodyear EZ-Coil doodads to go over generic hose. They're stainless steel slinkies that slide over the hose and hold its form in a tight bend. Also make that hose just a bit longer, so that it can make gentler bends. It's not a particularly expensive job when done this way. I bet ezzzzz and I bought our marine-grade 5/8 hose from the same place! Michael, there are lots of people who just replace what breaks and nothing else. There's nothing "wrong" with this approach. However, a lot of us like to replace everything that looks frail whenever it's convenient (e.g. when we're into the job). That saves us from a lot of diagnosis and wrench twisting, although we might end up paying more in parts in the end. Two different philosophies.

Yoshi, when your engine reverses (as it's dieseling), it will blow exhaust out your carbs. That will deposit all sorts of stuff on your air filters. Although it's possible to do a rough timing by ear and by feel (if you know what you're doing), I think it would be far better to buy a basic inductive timing light from your local auto parts store and set your timing the correct way. (It should cost you $40 or so.) The bottom-most pulley on the front of your engine is the crank pulley. It's got a shallow notch in it somewhere, and that lines up on a scale that hovers over the top righthand side (passenger side) of the pulley. You'll hook up the timing light to the battery and the front-most (#1) spark plug wire and run your engine. The light will flash everytime the #1 cylinder fires. When you point the light at the crank pulley, it will look like the notch is "frozen" in place beneath the scale. Then you twist the distributor to line up the mark at the correct advance, approximately 10 degrees on the scale. You'll want to pick up some general sort of "how-to" book to explain this better. Timing will also have a lot to do with the adjustment of your points, so you would check/replace/adjust those first. You'll need a set of feeler gauges for that. Again, that would be in a general how-to book. For the specifics of how your engine is put together and how to service and adjust it, I can't recommend a Nissan Factory Service Manual enough. Get one for the year of your car. The L28 under your hood is very much like your original L24. You can find them used on Ebay and Amazon for roughly $80, which is worth every penny.

Cute!

Michael, I wouldn't re-use any of the hoses, with the exception of the filler neck. That seems to be made of something like nitrile rubber and was in like-new condition on my car. But the hoses were all pretty tired. The problem with old hoses is that they oxidize and slough off a sooty debris that deposits itself throughout the fuel system. While the tank is down, you may as well start with everything being fresh.

Crikey, Jeff, now THAT'S RUST! Argneist, it shouldnt' be hard to drain the tank. Just pull the drain plug, and let it go. Drain it into a pan. If the hole gets plugged, just poke whatever is plugging it with a wire/stick/nail/screwdriver. I wouldn't have a hose list for you, but I can tell you everything is easy enough to find at your local auto parts store except the roughly 5/8" fuel-rated hose (DON'T USE HEATER HOSE!), which you can supposedly find at your local tractor supply company. If you can't find it there, give Hampton Rubber a call in Hampton, VA. Talk to them very nicely, and they might mail you out some. (They don't ordinarily do mail order.) Let me know if they say, "Oh, damn, what is it with you Datsun owners?! Why do you keep bothering us with this stuff?" (I have to get along with them for other stuff. ) Sublime, there's no way to remove the intake screen without cutting the tank open. My radiator guy quoted me about $500 on my tank to cut it open, pull the screen, eat out the rust, coat the inside, and put it all back together. Then he looked at my tank and said (with a wink), "Your tank is fine! Get out of here and stop bothering me!" He told me that an acid wash will eat the fine screen, and epoxy coatings will clog the screen (which might not be relevant if there's no screen left from the acid wash). A agree with Andrew that there's no reason to get too aggressive with the tank if it's in good shape. All I did with my tank was to pressure wash it, rinse with acetone, dry, repaint the outside, and reinstall.

Cool! A match! Yeah, the PCV hose connects between the crankcase and the PVC valve, which is screwed into your intake manifold. The PCV (positive crankcase ventillation) system is what returns exhaust blow-by to the intake to be burnt off, and it's also what airs out the smoke in your crankcase and keeps your engine cleaner. Check your PCV valve, while you're at it, to make certain it's good. It's very cheap to replace.

I think that's the PCV hose.

Well, you'll need a friend to help you. It takes one person up top to route the filler neck, hoses, whatever, while another person lowers the tank from the bottom. You might be able to do the removal yourself, but you don't want to get stuck under a bulky tank. It's good to have someone else there, just in case. For the replacement, you'll definitely need someone else to route the filler neck, hoses, etc., and to hand you stuff. Is it difficult for a noob? Probably not. It's just dirty. Cozye cautioned somewhere that the passenger-side (?) strap bolt tends to rust and break, but mine moved pretty easily. My tank was also in very good condition, so maybe it was replaced somewhere along the way. Spray the bolts with your Kroil, and you should be good. Try your bolts first. If they don't move for you, then seek the help of your relative.

Cool! Well, there ya' go!

I forgot to mention that the vacuum control hose runs from the vacuum switches on the righthand side of the engine compartment, through a grommet in the passenger firewall. Pull the hose off and try blowing through it. If you can freely blow air through it, either it's leaking, you have a hose pulled off somewhere, or that vacuum switch is crudded up -- in which case you'll need to pull your center console and go diving into your HVAC control stuff. (Have fun.)

Yeah, argneist, that's a LOT of rust! You've just now replaced your injectors and don't have any significant run-time on them, so I doubt you've done them any harm (yet). IMO, there's no reason to pull your injectors and fuel rail. Just drop the tank, clean it out, seal it, change your filter, and you should be good. Good thing you checked!

Buddy, my fuel pump relay would stay on too. The connection to which I refer is between the fuel pump relay and the fuel pump. As far as I'm aware, there are only three connections between the relay and the pump. The first is the plug that goes on the relay, the second is the harness connector inside the firewall, and the third is the post on the fuel pump.

I have to agree with Steve. I've soldered connections in cars for maybe 30+ years and more recently in boats for about 7 years, including a complete rewire of our powerboat. Obviously most of the connections would be smaller than 8 ga, but I've soldered up to 4 ga. I've never had a problem. OTOH, I've seen many a crimped connection fail, usually due to corrosion -- especially on boats, but also in old cars. Probably the most hostile connection I've soldered was the ABS sensor wire on my Saturn, which became ripped long ago. Rather than to buy the $$$$ part, I just soldered the wire back and heat-shrunk it. The connection wasn't a particularly good one, as it's always difficult to solder corroded wire. It's spent a decade (including in Ohio) exposed to salt, heat, and lots of flexing and vibration. No problems. I admit I wouldn't have as much opportunity as Steve for problems to surface, as I probably haven't worked on as many cars. However, I've had no problems at all. If you have problems with solder joints failing, you might not be leaving enough slack in your wires to flex without bending. Although soldering might aggrivate the problem, I don't think it would cause it.

Actually it's always good practice on ANY car to disconnect the (-) first and reconnect the (-) last. If you do that, then there's no risk of shorting the battery to the frame/body.

I don't know on that model whether any relay would be mission-critical, but I'd track the thing down while it's clicking back and forth for you! It's going to be easier to find now than when it fails altogether. Just sayin'...

I wonder if a dislodged battery would burn a hole in the hood with the posts flipped around. As far as I'm aware, the inspection lid protects the (+) post from accidental contact with tools and such. I'm almost positive that's how all the Z's came from the factory. I suppose there are good and bad points either way. It would probably make a lot of sense to put some thick, self-adhesive plastic on the underside of the inspection lid (or hood, depending on battery orientation) to insulate in the event of accidental battery post contact. They make the stuff for electronic use, but I have no idea where you'd find it. I suppose an insulating cap over the (+) battery cable connector would help too.

Eric, it might not be a vacuum leak. You can get a low vacuum with the engine running very inefficiently, where the throttle/bypass is opened up a lot to keep the RPMs up to normal idle. I suppose the throttle/bypass might be the vacuum leak, so to speak. Argneist, you're using too many tools! Your FPR doesn't need 18" vacuum to work properly. Rather, it needs whatever vacuum is inside your intake manifold. Its job is to keep a constant pressure between the fuel rail and the inside of the intake manifold. That way the ECU can deliver a specified amount of fuel based on how long it opens the injectors. Anyway, by drawing 18in vacuum at your FPR when your manifold vacuum was really 5 in, you were leaning out your mixture (by causing your fuel pressure to drop). But since you have that hand pump thingie and the vacuum gauge going at the same time, how about an experiment? Start without any vacuum on your FPR, and watch your vacuum gauge (on the intake manifold). Slowly apply vacuum to your FPR, and change your vacuum level around to find the point at which your engine idles its fastest/smoothest, with the highest manifold vacuum. That point would be your best mixture (at least at idle). Now compare the vacuum in your manifold with the vacuum to your FPR. That difference would be the amount you would ideally change your fuel pressure set point to achieve the ideal mixture. For instance, if you've got a manifold vacuum of 10 in and a FPR vacuum of 15 in, then you would benefit from an FPR that regulates pressure 5 in lower. Now divide roughly by 2 to find the difference in psi, which would be about 2.5 psi. So your FPR would be regulating about 2.5 psi too high. But then again, at vacuum levels that low, other stuff is clearly wrong. I'd guess it's a lot more than your FPR. You might hang on to your FPR for a while, even if it's regulating a bit high. That might be OK if other parts of your system are running you lean.

You can hook up the vacuum gauge almost anywhere you want. I think Eric likes to tap the line to the FPR with a T-connector. I prefer pulling off the HVAC vacuum control line near the brake booster vacuum line and measuring from there. Normal vacuum should probably be at least 17, and 19 if you can get it. I'm pulling 18.5 at idle. Higher is always better.

Zed, interesting that your FPR regulated differently hot and cold! I'll have to check mine sometime to see if it does that. Argneist, I meant to simultaneously hook up your fuel gauge and a gauge of known accuracy to the same compressed air source. They should both read the same. When comparing gauges, I look for consensus. If two read the same and a third reads differently, then the third one is probably off.

Argneist, you must be richer than Midas! You don't need a $150 inspection camera! Yes, you can inspect your tank. First use most of your gas up. Then drain the remainder of your tank via the drain plug on the bottom. Inspect the drained gas for debris. Pull the inspection cover to reveal the fuel level sender. Unplug the sender. Gently tap the retaining ring with a screwdriver and hammer to rotate it. Note the orientation and how the notches line up. Then gently pull the sender out. Shine a small flashlight through the hole. Use a small mechanic's mirror or dental mirror to peer around inside the tank. Debris from the tank won't hurt your injectors; however, it will clog up the intake screen on the intake. If it somehow makes it past the intake screen, it could harm your fuel pump. However, any debris will be captured by your fuel filter before it could make it to your injectors. The fine, soot-like debris from deteriorated rubber hoses has probably coated the inside of your tank. I'm certain it makes it past the intake screen, does not harm the fuel pump, and mostly gets lodged in the fuel filter, but I suspect some of it passes through the fuel filter and reaches the injectors. I suspect this would slowly diminish injector performance, so it would make sense to replace fuel hoses.

Oh, and yes, the pressure should hold for as long as possible after you shut off the engine. (All night is pretty good.) I've read others reporting that their fuel pressure rises slowly after shutoff, so I suppose it's normal. I suspect it's due to heat buildup and the vaporization of fuel in the fuel rail.