Zed Head

The "dead" part of the deadhead is the non-moving fuel in the rail. Dead flow. If the fuel doesn't pass through the rail, in one end and out the other, then it's a deadhead system.

Just an observation. The pros and cons of return style versus deadheading is a popular topic. https://www.bing.com/search?q=return+style+versus+deadheading

Run them through their range of motion and see how they feel. I had one from a parts car that had been rear-ended and it must have damaged the half shaft. It would bind in its travel. I took it apart but did not see any visible damage. On the u-joints, the factory joints have caps in the Zerk fitting holes. Remove cap, install Zerk, squirt grease. Check the seals.

Aren't we comparing about 16 + 6, to 16? 22 to 16. I just pulled those numbers from memory, the more precise numbers are out there somewhere. . .

Leaner with the new injectors or with and without the resistors, same injectors? I think that you'd need to do a one-to-one comparison as far conditions to really know. Engine temperature, air temperature, etc. With and without resistors. Otherwise it's just conjecture.

I wonder if Rain-X might help. Just because of how it works. Leaving a fine film of water repellent molecules on the surface.

With no load from a pump do you think the eccentric will really have much effect? The weight of the sprocket is far greater than that tiny cylinder of steel, placed near the center of mass. I tend to leave well enough alone. Just a counterpoint...

I did. When I first put the system together I left the resistors in place as I tested it. Then I removed them and jumped the wires, just because. Then I think that I put them back just in case a future owner wanted to swap back to the original setup. I thought about the possibility of low current causing delayed opening times but decided that the EFI system is so crude that it probably didn't matter. It's a semi-batch fire system with no O2 sensor trimming. It just squirts a gob of fuel every rotation to all cylinders at the same time. But, with your AFR gauge you could easily run a simple test. Extra resistance won't hurt the ECU. Worst case you see some leaning at idle, where injector open duration is lowest and delayed opening time might have an impact.

I thought the same. That won't help the hot start problem, might even make it worse since the vapors can't be purged except through the injectors.

Just noticed that Volvo used it also. A spreadsheet image.

I've mentioned this before also, somewhere. You can take an old Bosch/VW/Porsche adjustable regulator and drill a hole through the center of the adjusting screw to add a vacuum reference hose. There was an old VW dune buggy article about it on the web. Notice the 001 number. Might be the first adjustable from Bosch as they got in to L-Jet. Still available. Spendy, unless eBay. It holds pressure too. https://www.pelicanparts.com/More_Info/0280160001.htm?pn=0-280-160-001-INT https://www.ebay.com/itm/115896285815?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=JXCBKhvJSD2&sssrc=2047675&ssuid=bBzFtXzvTQO&widget_ver=artemis&media=COPY

Here is a GM injector I ID'ed in the past as possible. I pulled the data from various sources and stuck it in a spreadsheet. I got a new computer and Microsoft is holding the spreadsheet functions hostage so all I can do is an image for now. A person really needs an adjustable regulator to get things dialed in. Since you have to lean things out. https://www.rockauto.com/en/catalog/buick,1989,electra,3.8l+231cid+v6,1017414,fuel+&+air,fuel+injector,6224

Here's a link to a table I had found a while ago. The original web page seems down but the table exists in various forms. 028-150-105 seems to be the standard Bosch original form replacement for the Nissan analog. In those early days they gave different part numbers based on hose length. I think that up to -112 are the same basic injector. It downloads a pdf file. Those 712's are high impedance. You'll want to remove the dropping resistors, I'd guess. Although I ran high impedance on my engine and they worked fine either way. Looks like you might be a hair rich with those. Good luck. https://alfaclubvic.org.au/forum/index.php?action=dlattach;topic=13145.0;attach=28987 and https://www.google.com/search?q=stanweiss+injector

Just noticed that CO covered what I was talking about. Missed it in the flurry of posts. I'd measure the head thickness (you can do that while it's installed) then do the math on the the headgasket and see what should be. Meanwhile, order new timing gear - sprockets, guides and tensioner. All three can have wear.

On the 280Z EFI engines Nissan stopped using the dropping resistors in 1982, for both EFI and ECCS engines, according to the FSM's. The FSM mentions current and voltage protection, but the injector solenoid coil is essentially the same as any relay coil. Seems like protection would be more for the ECU. Of course, current and voltage are related. A resistor won't lower voltage unless there is current. So, in terms of "breakdown" voltage, it seems to be a wash. Must be a current issue. But the injectors are cooled by gasoline. Just some random ramblings... 1981 Turbo Supplement 1978 EFI. Current and ECU -

With a new chain and gear set installed you could loosen the cam towers and raise them to find what thickness shim you need. That's what I'd do (if I was starting from scratch). p.s. a thicker head gasket will lower your compression ratio. Not good. p.s. 2 - although, raising the towers and cam shaft will also require new lash pads, I think. You're kind of in a bind, math and calculations are required. . .

And, if you lift the cam towers you'll tighten the chain. It's a thing. https://zcardepot.com/products/copy-of-cylinder-head-cam-tower-shim-set-240z-260z-280z He has .015" also. You could stack them. https://zcardepot.com/products/cylinder-head-cam-tower-shim-set-240z-260z-280z?variant=19278543978609 Also, eBay - https://www.ebay.com/itm/134138328417?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=r5VbdHh0RZK&sssrc=2047675&ssuid=&widget_ver=artemis&media=COPY Or, looks like this one won't pop out. https://jdm-car-parts.com/products/adjustable-timing-tensioner-for-l4-engine-by-kameari?variant=39843755425901 . . .

Something for the carb guys. https://bringatrailer.com/listing/mikuni-44phh-carburetors-and-intake/ . .

The biggest one. The one that goes back to the tank. The one that you tried to blow through. Is it open now, connected, or blocked? You said earlier that something was disconnected. Trying to figure out where the end of the main hose is. If it's still connected to the canister but the purge hose is disconnected, the canister can get "full". The charcoal only absorbs a certain amount of vapor. Fumes in the engine bay can get sucked in through the cowl vent, and leak in through the various holes in the firewall.

Is one tire breaking loose or both? Looks like you still have room to lower the car. That will make a big difference. And anti-roll bars.

My question was about the big hose. Where the fumes would be emitted. Did you block it? That will pressurize the tank. Did you leave it open? That will cause a gas smell as it's open to the tank. Did you leave it connected but with no purge line to the intake manifold? That will also cause a gas smell after the canister charcoal gets loaded with gas vapors.

Actually, the gas cap is sealed and should only let air in, through the "vacuum relief valve". Gasoline fumes from expansion go to the charcoal vapor canister, fresh air is let in through the valve on the gas cap to replaced fuel burned or volume contraction.. I found that the seal on the relief valve on my cap was shot. The cap design was changed for unleaded fuel cars and is still available. The older big-mouth caps are hard to find and very expensive. I just lived with the faint smell. Can't remember what CIC is working with. https://www.classiczcars.com/settings/signature/

The F54 block has the holes for the gussets. The N42 block does not. In case you were thinking about a retrofit.

Nissan knows. What did you do with the open end of the hose? And, to be clear, which hose is disconnected. And, more clarity, the canister itself doesn't "hold vacuum". It's wide open on the bottom. The cap on the top controls vacuum to open the purge line that pulls through the canister.