Zed Head

That may be the most important wire of all. Did you complete that circuit? Note in your picture the blue wire with the bullet connector to the BCDD solenoid. Maybe that's your extra wire.

Who is the seller and why would they blame it on your car? Did they advertise as a 280Z bar or do you think that they are scammers? It's common knowledge that the 280Z strut towers are taller and closer together at the top. 240Z = 853 mm center to center 280Z = 836.4 15.6 mm - 0.6" Share, so that others can avoid your fate.

Not a short. No connection at all. The blue wire runs to the ignition module to make and break the electrical circuit to the coil, to provide spark. That's why you have no spark. It also branches off to the tachometer. And the ECU, to provide the signal for injection. Zoom in on the lower left of the picture I provided and you'll see the ballast resistor, coil, and the blue wire.

I think that blue wire is the key. I didn't go in to all of the details of the blue wire but it also runs to the ignition module and the tachometer, branching off to each along the way. I think that you should check the wiring diagram and get that blue wire connected to where it should be, before buying any parts. Does your tachometer move when you're cranking the engine? That would be a clue. Here's a picture and a link to its source. It's 1976 but 1977 is essentially the same. http://www.classiczcars.com/forums/open-s30-z-discussions/36494-free-full-color-wiring-diagram-1976-280z.html

Apparently the NA 280ZX and 240Z both use the same 25 spline axle pattern and size on the companion flange. So you can swap a 280ZX companion flange on to 240Z axles and use the 280ZX CV driveshafts in place of the stock u-joint driveshafts, if you have the clip-in axles in the diff. The CV driveshafts have the axle connected to the driveshaft as one unit, it's not bolted on. The only part that takes more than wrench turning is the dust shield, it needs modifying. So there are 240Z's out there with CV axles, but they're not factory-produced. I can dig up a writeup I found on the interweb that I have saved somewhere if anyone is interested.

Did you actually check for spark with a spark plug on the end of a plug wire or are you assuming because you have fuel in the fuel rail and nothing happens? The one disconnected L (blue) wire might be the signal wire to the ECU to fire the injectors. It should be connected to the same post as the wire to the negative terminal of the coil at the ballast resistor. Without that wire, no signal to the ECU, no injectors spraying fuel. Maybe. Your picture doesn't show where the wire ends are, which is the important part.

I second the fork seating possibility. The angle of the rod is wrong, it should be close to a straight shot to the seat in the fork. Looks like the fork is sticking out of the transmission too far. That means the fork ends (tines?) are not riding on the throwout collar correctly. Grab the fork and wiggle it and see if the spring clips are holding it on to the pivot ball. If it's loose you might still be able to force it on without removing the transmission. Push it in to where it should be, where the angle is right (almost a right angle with the rod), and press the clutch pedal.

When I cut my springs I heated a point halfway around the coil on the cut end to red hot and bent it to give a flat perch for the spring. Otherwise the bottom coil sits on the point of the cut portion and puts bow in the spring. Maybe they did the same. If you can see the spring perch you might be able to see signs of heating on the last coil.

Where there's rust there was/is water. Could be that you just have a puddle of separated water at the bottom of the tank and some sloshed over to the tank outlet. If you haven't looked at your plugs in ten years, I'm going to guess that this not a daily driver. Does it sit for quite a while between drives? Today's ethanol-containing gas will suck up water pretty quickly if it can. Are your charcoal canister and gas cap intact, to keep the tank sealed from the atmosphere?

How big is the park and what was the drive like? Were you showing the neighbor what the car would, with some high RPM stuff or was it just a mellow three or four block trip? Were it me I might drain the tank contents, change the filter, and refill with new gas, just to take that variable out of the picture. You can use the fuel pump to drain the tank by running a hose from the filter to your portable tanks, removing the solenoid wire and turning the key to Start. As far as other sources, what was the tachometer needle doing while the bucking was happening? If it was moving faster than the crankshaft could possibly move, jumping and/or reading abnormally high, you might have an ignition system problem, maybe the module.

Harbor Freight has a ball-joint splitters that are fairly cheap but look sturdy. The mechanical type, not the pickle fork. Looks like it might work. They had a 20% off coupon going for the summer too. Found a picture of it on the Google. 3/4" Forged Ball Joint Separator Put the tension on and wack the side with the hammer.

Don't forget to factor in boiling temperature depression due to intake vacuum on the PCV system! Nissan got more specific on thermostat temperature choice after 1972. Here's the 1976 chart. You still have to figure out Tropical and Cold. There's probably some general world-based definitions out there somewhere.

Here's a picture of something I did just to see if it would have an effect. Big steel washer, and big rubber washer that fit the outer diameter of the bar but with a big hole in the middle, for up and down, and also smaller washers that fit just inside the inner diameter to reduce side to side. The rubber was just to avoid any buzzing or rattling. The picture is with the jack under the diff but you can see that the bottom scalloped washer still is compressed. I had more installed than shown at one time, enough to transmit diff noise to the cabin. Ace Hardware washers, nothing fancy. It was a good experiment for my purpose. Edit - might as well show my next experiment, to try and avoid the diff noise from the urethane bushings. I cut a boat trailer roller in half for the top bushing, and used the urethane on the bottom. Urethane kept the diff located side to side and the looser bushing on the top damped the up and down. Worked well, but looked ugly and started showing signs of age. Eventually went to all urethane but with an air gap to avoid noise transmission.

A blown head gasket will cause overheating. Check your radiator also, it may be plugged. How did the old water pump look? Were all of the blades intact? Does your fan clutch work? Maybe the overheating happened after you got off the freeway and did a lot of stop and go driving. There are a variety of methods for checking if you have a blown head gasket. A cylinder pressure test might show you something, along with the appearance of the spark plugs and piston tops. The missing thermostat is a sign that the engine had been overheating for a while. It's one of the thing people do when they don't understand the root cause of the overheating problem. One scenario is that overheating started from a bad water pump or radiator, leading to a blown head gasket, leading to more overheating after the common fixes were applied. You might have a warped head also, they don't like overheating.

The port at the back right of the head is only for the heater core supply. It actually affects flow in a negative way when coolant flows out at that point. It's a necessary evil to keep the people in the cabin warm. Some other car models used what's called the block drain plug port, under the manifolds, as the source for heater core supply. Here's a diagram of the coolant flow. Notice that the heater core supply is not even shown. Coolant flows through the block, up in to the head and forward to the thermostat housing, then out to the top of the radiator.

You grind it, you bought it. I'm sure that will void the 30 day warranty. By wipe pattern, I meant the area of the rocker arms that the cam lobes ride on. Checked by blueing the pad, then rotating the camshaft and seeing where it rubs. It's described in the Monroe Rebuild book, page 109. A good book for you to have, if you don't already. At least check wipe pattern before doing anything, if it's off you can spend a lot more money trying to make it right. Plus it's a good indicator of the quality of the rest of the work. I hope that it's a good buy for you, but I would not buy anything from DatsunParts myself. Besides his past reputation, his eBay ads, which you must have looked at, look shady. Good luck.

So the main question is how to keep the fuse from blowing. Fuses blow when they get too hot, usually from too much current but sometimes from corroded connections in their vicinity. Clean up the connections to the fuse and around it to make sure it stays as cool as possible. Look for short circuits on the fuel pump power circuit.

I don't think that you can generalize all mechanics in Panama from the work on one modified old 240Z. You didn't really define a problem in your post. Does the fuel pump fuse keep blowing? Does the car start now? What is the current state of the car, you've only described something that happened in the past. Have you looked in the FSM at the basic adjustments for the SU carbs? Pretty sure that there are some simple things you can check.

Overheating from bypassing the heater core was demonstrated by Tony D on zcar.com a couple of years ago (data seems to be deleted now). Apparently, with no restriction between the head outlet and the water pump inlet, the water pump ends up re-circulating too much coolant from the back of the block, instead of running it through the head and the thermostat. Basically reduces the total flow through the head. If you don't get a heater core soon, just block both holes and the coolant will flow through the head like it's supposed to.

Not to put a damper on the project, but you should check that head carefully, or have it checked professionally. DatsunParts LLC is not known for their expertise, they(he) are(is) just very persistent in a market that has few options. A few years ago he sold some pretty poor work. Word is things might be better now, but early on it was obvious that he just collected parts, then re-assembled them in to packages. You could have a mis-matched set of rocker arms and cam, for example. Check the wipe pattern, check the lash, re-torque everything. Check the head thickness too, to see if the cam towers should have shims or not, calculate what your new compression ratio is since the head has been shaved. Check the spark plug threads before installing the head. If it was a Rebello head I'm sure you could not worry, but still would be worthwhile checking. This guy - you have to verify what you have.

The fine people here can get you close but you won't really know unless you dig in yourself. The EFI harness is almost completely separate from the body harness. It has its own power wires and ground wires. There are connections to the fuel pump relay, which you may or may not need for carbs, and a few other indirect connections which aren't needed to power the car and can be disconnected, like the wires to Pin 1 from the coil (although the wire does need to stay connected to the tach). But, you said you pulled an "engine harness". It's not really clear what that is, the EFI harness is a separate harness and doesn't have a voltage regulator connection. Your best option is to study the wiring diagram and see what you can figure out. A few member of this forum have worked up some nice color diagrams. Here's 1978, and 1976 which is close to 77. 77 might be out there somewhere too. http://www.classiczcars.com/forums/misc-s30/44992-somewhat-color-wiring-diagram-1978-280zs-enjoy.html http://www.classiczcars.com/forums/open-s30-z-discussions/36494-free-full-color-wiring-diagram-1976-280z.html

The wrecking yards in my area get the year wrong all the time. If they went by the build date, it might be a 78. 78 had the internal regulator.

I think that Kerrigan's quest may be to find out what's true and not true. How do you know? Lots of conjecture out on the internet. For example, all of my comments in this thread about no need for L20A until there was L20B are wrong, if the information in the links in Post #21 are right. Apparently there was an L20, then an L20A, then an L20B. Apparently, according to the internet.

By "cooling setup illustration", do you mean the water jacket outlet on the side of the head? You don't have that?

Many people reuse them. You can tell when you get in to the locking part of the thread, it gets much harder to turn. Other nuts on the car are self-locking also, like the ones on the two long transmission cross-member bolts. But, the FSM recommends a new nut. On the axle, probably best to go new. You can still get them at your dealer, I believe. They even show up on the Nissan data base. $4.98 each. Rear Axle :: 280ZX Parts (S130) 1979-1983 :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com