Zed Head

He has a fuel pressure gauge inline apparently. So that should tell if there's a clog. Just saying, he's already head of the game, with the gauge. This just reminded me of the other big sneaky thing that gets people - the fuel pressure regulator (FPR) might have a hole in the diaphragm. Pull the vacuum line off of the FPR and check it for fuel. It kind of fits the symptom, with a small hole getting bigger. The diaphragms get brittle with age. I have an old one that cracked in to pieces when I took it apart.

That's a pretty good clue. Plus the fact that it runs better with vacuum leaks. The fact that it slowly got worse is odd. But it definitely sounds like too much fuel. So that could be injectors staying open too long (ECU controlled) or the CSV leaking (easy to check), to the AFM sticking (also easy to check). Could be that somebody tuned the engine to run with vacuum leaks and when you remove them it runs poorly. Can you crank up the idle speed so that it stays running? That will allow you to examine the parts that could have been "tuned" to incorrectness. I would pop that AFM cover off first thing. Make sure that the AFM vane is moving. Its position has a direct impact on injector open time. It's not uncommon for them to get stuck.

You haven't provided any numbers so it might be that you're just using continuity as your test indicator. You can get fooled on the coolant temperature sensor (CTS) if its connector is attached to the thermotime switch. Make sure that the CTS is correctly connected. Get an actual resistance reading at the ECU and compare it to the temperature chart in the FSM,or the Fuel Injection book. Since the black cover on the AFM is already gooped up with silicone you might as well pop it off and watch the big weight move while the engine runs. Make sure it's moving freely. They've been known to get stuck, showing more air to the ECU than actual. Make sure that your idle setting is high enough to keep the engine running when things are right. Maybe it's set too low and the engine needs the extra air from a loose hose or two. Just thinking outside the box. At least it runs so that you can mess with it.

How do the spark plugs look? Easy to get to and might give you some clues. One reason to do a little detective work early is because you might find that the engine is not "refreshable". Hope that's not the case, but something like a big scratch n a bore can add a lot to the cost, to fix. Better to know now than have the mechanic tell you in a couple of months. Might make your L28 decision easier too.

Just to add to the possibility, and because it could be a while before anybody gets a chance to actually look at the bolt. I snipped a few pictures from the carparts site. The drawing shows line on the mustache bar bolt which seem to indicate a change in diameter, but none on other bolts. Don't know if it means anything. Maybe a draftsman knows. The FSM picture looks like an actual taper, but 2/3 up, with a step. I've never looked closely at the bolt in the several times it's been exposed. Now I have good reason to remove one of those bolts if I ever find another Z n a wrecking yard. They are much sparser now than they used to be just a couple of years ago.

There has to be a used L series engine out there somewhere that you could swap in. They're surprisingly durable. Even a junk yard engine would probably get you by. Despite the weird noises there's always a chance that it's just a head gasket. Might just pull the head first. And/or drain the oil and see what's in it.

Are you using the FSM drawings? You need a reference. I install mine by putting all of the springs in to their respective holes, laying on the shop floor, then grabbing both shoes and folding them like a book. Keep tension on them to keep the springs from falling out. Place the proper contact points on contact points and open the book, pressing the shoes on to the backing plate. The springs will stretch as you get things in place and the book will try to stay closed. Then use a knee or a friend to hold them there while you install the little retainers.

I did measure the hole in the top stopper though. 15.7 mm. So, approximately the stud/bolt size.

No pics but I distinctly remember that the washers that came with my bushing kit had different sized holes. I put the small one on first and had to take the bar down to swap them because it got jammed halfway up the shaft. If somebody has a kit they might be able to measure or eyeball. I think that I have the old factory stoppers out in the garage that might show the same. I'll dig around. Edit - found the parts and took some pictures but realize that they don't confirm a taper. The small one fits on the step on the end of the shaft, for the nut and washer. The kits come with a sleeve that fits over the shaft, so the washer with the small hole only has to be smaller than the sleeve hole. A different system. Could have been "wear and tear" taper, and the washer that came with the kit, that was only needed to not slide over the sleeve, "almost" made it up the shaft. Maybe a non-issue.

Not sweating, just getting facts straight. American technology. Probably American tape. The final puzzle is why the schematic looks British. (emoji here).

It gets more interesting - Compu-Tronix is apparently taking credit for 3906920 now. Whoever they are. http://www.hotrodhotline.com/pr/2011/compu_tronix_american_v8/

It's still undefined. Per-Lux is a mystery firm. You're right though, there doesn't seem to be a U.K. link. Is Hemphill a British name? Maybe that's it... https://www.google.com/patents/US3906920 He's looking Californian, Silicon Systems. https://www.google.si/patents/US3581720 "both of Balboa, CA" - Then Fountain Valley in 3906920, above.

That bolt/stud has a taper. As anyone who got their washers mixed up from the typical PU bushing kit would find out. Don't know why.

Bessie that, assuming that all "tape" is the same and that a good engineer couldn't specify one that did the job is a bit misguided. The tape has worked for thousands or hundreds of thousands of people for hundreds of thousands or millions of miles. It's simple, easy to manufacture, and apparently cost effective process, based on the price of the final product. It's been working fine.

Typical corporate hype story, distributed around to various parts suppliers to make the brand look like it has history. Doesn't' say anything about where Per-Lux started, or who "the engineer" was. He could have been a Lucas engineer.

The part spins so whatever makes you think that it will stay on at high RPM.

That's the right car but Rockauto has the wrong part for it. 1981 was unique. Their compatibility table shows that it's for the later distributor style sensor. You have a big problem. You can convert to the distributor mounted sensor easily but those are hard to find also. borini63 has always been good for old ZX parts. @borini63

I did leave the thought a bit unfinished. When I look at that stamped piece of steel, that only covers half of the length of the cover I think that some engineer somewhere (probably at Nissan Motor Corp.) must have put some time and effort in to it. Can we really just throw it all away? Save some of it. Is there a purpose to those bends and that shape?

http://www.thezstore.com/page/TZS/PROD/12-4020

I pressed out my front control arm bushings with a vise and some well-chosen sockets. Heat made the difference. No heat, no movement. They even stopped moving as the metal cooled after I removed the torch. Pretty sure that people have bent tier arms also, so more force might not be a good option, if it comes to mind. Unless a brace is used in between. Heat.

It wouldn't be as clean and neat on the inside but a person could run a tube to the area of the exit port under (above) the baffle then run the tube to wherever they wanted the new exit to be, inside the cover. You'd have the same design that was originally engineered, except for the volume that the tube occupies. If the multiple bends in the baffle have a function it would be maintained.

That was my point on the other forum, but based on adhesion to the metal base. Wasn't aware that "nano clay" was used in the PU material. Where did you get that information? An aside, and no offense intended, but "nano" is one of the most over-hyped, and incorrectly used terms in the materials world, in my opinion. Anything can be described in "nano" terms. It's just a unit of measurement. A personal peeve. I think that it got its popularity from Mork and Mindy.

Don't overlook that there are two switches involved n the headlight circuit - the power supply (the main switch on top of the column) and the power ground (the dimmer). For whatever reason, the dimmer switch doesn't seem to foul, or heat up and fall apart, like the main switch does. Although it does seem to get gummed up and need contact cleaner. The main switch does have two circuits side-by-side though, the running lights and the headlights. So, more total heat. My point was going to be that you can do one at a time. I bypassed the power sixths with a relay at the fuse box, but left the dimmer switch alone.

There was a thread on a different forum about using two part urethane to pour your own engine mounts. I commented that sufficient adhesion might be difficult to achieve, considering the shearing forces at the interface of "rubber" and steel, but this application seems about right for it. If the material fails everything is captured so that no parts come loose, unlike the motor mounts. Remove the rubber from the bar end, build a mold, and pour. The inside of a mustache bar end will give the dimensions needed to find a replacement from another car. I have one with the old sleeve still inside. There are really two dimensions that you could consider, old sleeve in, or bare bar.

Doesn't the evap line have a check valve in it?