Zed Head

Are you asking if 4659-2700 = 22612-E3001? Or of the cap is from a 240Z factory car? You can still buy 22612-E3001 from Courtesy Nissan for $26. http://www.courtesyparts.com/cap-dist-p-277372.html Since Hitachi is an Original Equipment Manufacturer (OEM) for Nissan, I think by literal definition, that is an OEM cap. Literally.

This is not a sign of a bad pump.

I'm in the water-in-gas crowd. If you're seeing water in the filter, then there's water in the tank. You need to drain all of your fuel, flush the lines, dry the tank out, replace the filter, refill, then add HEET or some other drying agent to disperse the remainder of the water. HEET is not going to fix that much water, if you're seeing it in the filter. Plus, the water will soak the paper of the filter, and it will swell and cause a flow restriction. But, are you sure you're seeing water? The filter can get an air bubble and still function just fine.

I've seen a few threads about detonation and those small marks that look someone used gravel as shot to clean the pistons are typical of the marks detonation leaves, apparently. Detonation can break rings so you'd want to pull the pistons at least. Not a throw it together and go short block, I'd guess. The big gouges look like foreign object damage. I've also seen in a small block chevy motor that hydrolocked, that when the connecting rod bends sometimes it twists. A piston was twisted in the bore. You might put a straight edge across the top and see if all of the piston notches line up. Looks like it has some good parts though. A 3 pulley damper, new water pump, good front cover. Might be worth parts alone.

Body Electrical has a wiring diagram that will show you how the tach works. The coil can't get power unless somebody wired around the tach, The chapter also describes how to remove the tach, No need to tear apart anything. The tachs do go bad. http://www.nicoclub.com/FSM/240z/

The 260Z came stock with electronic ignition from the factory. It was the first year of electronic. It's probably the stock ignition system. The wiring schematic and diagrams are in the nicoclub and xenons30 link provided before. Engine Electrical chapter, for one.

There's a break-in recommendation in the Owner's Manual. Looks like 1000 or 2000 miles is a common number. But those procedures were written when all oils had ZDDP, and may not even be concerned with cam lobe wear-in. So you're kind of in uncharted territory. Pretty sure I've seen higher numbers recommended, out there on the interweb, specific to the ZDDP problem, for new cams and rocker/lifters. Modern engine procedures won't work since they all have roller rockers or lifters.

He has a ZX P79 head. Somebody ran the pigtail to connect it to the coolant temp sensor circuit but didn't finish the job. Compare the image below to post 38. If he finds a meter and uses it right it should be an easy job to find the bullet connectors to the coolant temp circuit then run some wire to the CHTS. Can't get much simpler. On the engine - there should be some letters and numbers molded in to the block beside the driver's (left) side motor mount. Either N42 or F54. 1978 stock is N42, 80-83 ZX is F54. They're both good engines. http://www.xenons30.com/Engine.html

This -

Here's a picture I took long ago of my 76 wires. Your 78 should be very similar. Look for wires with bullet connectors.

You have all of the puzzle pieces now. Your stock engine had, and may still have, a coolant temp sensor right next to the water temp sender (for the gauge), in Post #39. The wires to the sensor would run right next to the wire to the sender. The sensor might still be there and it might still be connected. If not, you need to find the wires and extend them all the way over to the two white wires connected to the cylinder head temperature sensor (CHTS) in Post #39. They do the same thing. That is not the stock head that came with a 1978 car. Look at the numbers on the head up by the #1 spark plug. It's probably a P79.

Your coolant sensor is on the front of the engine close to the distributor, for 1978. The wires to it come from the same harness that injector wires do. ZX engines use a CHTS that looks just like it, but it's mounted on the back right side of the engine close to the battery. It's pretty common to find a ZX engine in a Z.

The wire to your sensor should be in the red circle in my picture. That was my point. Not where your picture showed. Think it through.

You're looking in the wrong spot, and maybe at the wrong sensor if you're over there. Or you have a ZX engine with a CHTS. Added a picture that shows where 78 wiring would be. Here's some links to various helpful sources - Guides, use the 1980 one - http://www.xenons130.com/reference.html FSM, read Engine Electrical and Engine Fuel - http://www.nicoclub.com/FSM/280z/

If you're on a budget, a wrecking yard Ford F150 pump might be an option. They're factory issue Bosch pumps. They have the long cylinder form though, like the Airtex. Late 80's / early 90's BMW's use them also. Many of the EFI sysems I've dinked with in the yards are still pressurized with fresh fuel, even though they drain the tanks. I'd rank quality as new Bosch > used Bosch > parts store Airtex. I wouldn't buy a new Airtex today although the one I have is still going strong, after about 5 years and maybe 50,000 miles.

Bummer! Hope it doesn't last for you, it gets old real fast. I made some injector insulators from old cellulose sponges (so they wouldn't melt, and because they're low heat conductors when dry) and the problem went 98% away. I understood when Nissan went to those plastic one piece injector mounts over the cool looking two piece mounts after seeing that. Might also explain some of the differences people see in addition to fuel. Later, and recently, I filled up with premium fuel over the usual 89 octane I get. So I'm back to no problems even though we've had some high 80's days here. I think that I might have been filling from the same big tank of 89 at my usual station and it was a funky winter blend. I'm sure that 89 doesn't turn over as fast as 87 and 90. Anyway, try some insulation around the injector bodies and see what happens. I had also placed some Mylar film between the injectors and valve cover just to buy a degree or two of radiant heat deflection, and found that the hole in the center of the manifold between three and four gets very hot. Enough to cause the bubble film to deform there. Your 78 probably has the webbed manifold with the little screwed-on sheet metal cover, but that's the hot spot I think.

Nice pictures. I wouldn't be surprised though if he had an aftermarket pump. Have to crawl under and see. Running the pump backward might break it free if it's jammed. Not sure if the stock pump does this, but the aftermarket pumps run fuel right over the electric motor. So moisture and crud can screw that up also. A new aftermarket pump is about $100 at the parts stores. Looks like other places are having sales though. The Airtex E8312 is a common one. http://www.amazon.com/Airtex-E8312-Electric-Fuel-Pump/dp/B000DT7Y7K

It only takes a little bit of moisture to get in to the pump and cause rust, or a few rust particles, and jam things up. The pumping mechanism is just small roller bearings on an eccentric mechanism with tight clearances to push the low viscosity gasoline. Not much to it. I wouldn't be surprised if the pump is just jammed, from sitting. If the motor windings haven't been damaged you might be able to get it moving again with some hard taps to the body. Jack up the back, or one side and remove a wheel, check voltage, then tap it with a hammer and see what happens.

Forgot to say, at first glance the way a regulator works is kind of counter-intuitive. The fuel doesn't push the valve open from the small port in the middle, it fills the volume under the the diaphragm and pushes it up, lifting the valve open and letting the fuel out the center port. Make sure you have your ports right.

It's not really clear that fuel isn't flowing and the carbs aren't getting fuel. You said that fuel flows from the return line, but not clear if you meant from the tank or from the line after passing through the system. In other words, summarizing, it looks like you're saying that you have a gauge that reads zero and a pump that shakes like crazy. But the rest is kind of foggy. Fighting fuel from the return doesn't make sense either. Can't figure it out. Is the regulator adjustable? Could you have the lines backward at the regulator? If you plumb the inlet line from the pump to the return port on a regulator, the pump will not push any fuel. It can't push backward through the regulator.

If your garage has sturdy framing you can use a come-along and move the car, then drop the engine on to a dolly. It makes people nervous if they haven't done any woodwork though. You can spread the load with an extra beam.

Racing oil with zinc complex is still available. S30Driver posted recently about a sale on Valvoline VR-1 at NAPA. Post #48. http://www.classiczcars.com/topic/51299-zinc-additives-cam-shaft-or-rocker-wear-and-mileage-a-poll/page-3 Pennzoil has one also, GT Performance Racing oil. Post #24, same thread.

Methyl hydrate being methanol? With a little hydrogen dioxide added or straight up? I did try ethanol and it cuts through it pretty well. I think the clean rag might be one key. Seem like fabric softener or lanolin is everywhere. I've never had any luck with newspaper. Maybe paper and ink vary geographically. I took out my Home Depot carpet to see if I get a few more days or weeks per cleaning. We're hitting hot weather here so outgassing should be high.

Those are some good points. Don't forget that the system grounds through the distributor body. Coil > points > distributor body > ground to engine block. You might just have a bad ground.

One more goofy 76 switch is the "top gear switch" that actuates the vacuum advance control solenoid. It runs through the transmission switch though so you'd need to extend the wire from the switch location. Looks like they used it to power a lot of small loads, like the hazard switch light and various gauges. It's fused though.