NewZed

It's common for the Z's. Not sure how bad it is for the ZX's. Search "surge tank" and/or "swirl pot" on Hybridz. Use Google and "site:hybridz.org" if the site search engine doesn't find anything.

I think that the seals are different also. You might look at everything involved to get a good working and sealing door. Besides the oddness that the next owner will have to deal with. Are the hinges the same? You could remove all of the latching hardware and test fit the doors. You'll either see just a latching problem or things will be more complicated than you anticipated.

Since you only drove it once, apparently, the problem might have nothing at all to do with the tank work. Coincidence. Do some basic troubleshooting and determine if it's a spark or fuel supply problem. Use the FSM and the Fuel Injection Guide. You can get them at nicoclub.com or xenonzcar or classiczcars.com.

Some people slip a hacksaw blade through the hole and cut a slot, then bend it in with a chisel and work it out. But a large vise, the proper size socket or similar for pressing, and a torch for expanding will do the job also.

Here's what the original bushing looks like - https://zcardepot.com/suspension/rear-suspension/spindle-pin-bushing-oem-240z-260z-280z-70-78.html Many people leave that one alone if it's in good shape.

http://www.chequeredflagracing.net/Datsun.html

The clevis pin for the pedal to MC rod connection can get a notch worn in it. This will click. I had the problem and anew pin fixed it. They were still available from Nissan a couple of years ago. http://www.carpartsmanual.com/datsun/Z-1969-1978/brake/brake-clutch-pedal 8 73 and later - http://www.courtesyparts.com/oe-nissan/46123h850a

Seems like you're really stretching the assumptions out. Leaded gas had been used for many years without valve-sticking problems. Has it been the same valve each time? Then it's a sticking valve problem, not valves. Seems like you could fix the single valve problem and be fine.

Might be easier to swap the propeller shaft yoke instead, if you can find one. The 240Z's have removable u-joints. Don't forget to consider gear ratios.

Pushing the AFM vane makes the injectors stay open longer, so more fuel at the low pressure. So it does seem like a fuel supply problem. Have you tried pinching the fuel return line to verify that fuel pressure can actually go higher than 38 psi? You could pinch and rev and should get the same effect as opening the vane. Or pressurize the FPR reference (vacuum) hose to increase fuel pressure. Could be the problem is that fuel pressure just isn't rising when the intake manifold pressure does.

The bearing inner race is the outer support for the axle. So if you have a stock bearing and a stock axle it doesn't seem like that end would have any "non-stock" action. Seems like the axle slop would be at the clip end. Is it rocking on the bearing race, like loose splines, or is the bearing race itself moving up and down? It's a tapered bearing so shouldn't really move. The axle has a surface for the bearing and another step for the seal, I believe. The seal won't support anything. Do you have any stock diffs to compare to? Might offer a clue.

Many shops charge a "flat rate" also. Sometimes they win, sometimes you win. Here's a tool - http://repairpal.com/estimator/ford/focus/front-wheel-bearing-replacement-cost

How about a holed FPR diaphragm? At intake vacuum a small amount of extra fuel gets pulled in to the intake manifold. At any boost level at all intake air gets pushed through the diaphragm, replacing fuel with air in the fuel rail. Instant lean condition. Plus only the FPR spring is controlling fuel pressure as the air leaks past the diaphragm so pressure control stops. Fuel is much more viscous than air so the difference between the two leaks would be large.

I've expended quite a bit of work on engines that just needed new plugs, cap and rotor. Did you try a basic tune-up?

You'll know more when you get the second one done. How long did the job take? Most shops have an hourly rate. This is not a Z? They don't have sealed bearings in the front end, and no hub to press in. The hub can be handled without the steering gear. Sounds like you took a big bulky thing in and just thought about the simple operations, not everything involved. You probably pissed off a good shop just to save $10.

There's a labeled drawing in the Service Manual. http://www.nicoclub.com/FSM/280z/

Not in-line, but shafts parallel. Crankshaft and pinon shaft. That's why people use the laser method. It can be difficult.

By parallel, I mean side-to side also, not just up and down. And don't forget your half-shaft u-joints, if you're using those. Or a bad CV joint. And the u-joints on each end of the driveshaft need to be in phase. In case you made it yourself. Might have missed it. Fun video -

There's actually quite a bit of old stuff on the forum about how to set the transmission/motor and differential angles. Those are what matter. Their axes have to be parallel. The driveshaft angle is a side-effect. Use Google ans search "site:hybridz.org driveshaft angle", or "driveshaft vibration" and you might find something. Add "laser" and "alignment" and you'll probably find jmortensen's thread on a laser alignment method.

Pretty sure he already has the recommended diff. RebekahZ's diff is in the paragraph in all of his posts describing his car's mods. And most 280Z's came with a 3.54 R200. He just needs an LSD to go with it.

Beautification.

I think that the Service instructions you want are here, in Part 1 - http://www.classiczcars.com/files/file/20-1970-71-240z-factory-service-manuals/ Pretty easy to open for inspection using normal tools. Some special tools required to disassemble it. I took another look at your picture and don't think that that is an early 240Z 5 speed. Might be a later model competition 5 speed. Can't remember the details of how to tell (there are threads on this forum - search competition 5 speed) but your shifter mechanism is the newer "B" style, not "A". So any of the other 1977 to 1983 5 speed instructions will tell you how to open it up. I'd go with 1983. Your rear case looks like a later ZX style. But your output flange is odd. Might be a hybrid transmission. Might be a truck transmission. Doesn't look a like a 240Z transmission. And it looks like the cases have been split recently, they're clean and different color. http://www.classiczcars.com/files/category/9-factory-service-manuals/

I think that he already has a car and he's just going to buy one of these two for the engine or the turbo parts alone. The car body and extra parts will be sold. Look at the other parts like the transmissions and differentials. Determine the value of the other parts, and do some math. Wrecking yards will always give $100 or so just for the value of the metal. If the engine in the bad car runs and can be evaluated I'd probably go for it, especially if you're going to use the ZX ECCS engine management. You'll have everything you need, working. You'll have a running turbo engine for the the car you have, plus a running spare NA engine for when you blow up the turbo engine. The locked up engine car could leave you with a pile of parts and still no turbo engine. Who knows what else is broken in the locked up engine?

A late 80's Pathfinder/Maxima CAS and distributor can be made to work, kind of like this Jeep sensor swap, but with a little more work on the L6 mounting stand, the hole is 1mm too small, and the stand is 5mm too tall. Then you could use DIYAutotune's replacement trigger wheels. https://www.diyautotune.com/product/54-mm-optical-trigger-wheel-for-nissan-l28et-or-vg30e/

This guy has moved on to bigger stuff, like complete cylinder heads, but he might still have some of these. http://forums.hybridz.org/topic/121177-just-finished-a-new-run-of-edis-mounting-kits/