Dave WM

Assuming you have spark and its to the correct plugs, and assuming the fuel pressure is correct your next test will be to listen to the injectors to see if they are clicking while cranking. That will let you know the ECU is working. Use a mechanic stethoscope or even just a long screw driver with the tip touching the injector body and the other side if the LONG screwdriver held up to your ear. You should here it while the engine is being cranked by the starter.

Start with the basics, pull a plug, lay it on the valve cover, connect the plug wire, crank the engine, does it spark? If it does double check the firing order. Next, look at the plug, does is smell of gas? wet with gas? completely dry? install a fuel pressure gauge crank the engine does the pressure shoot up to 36-38 psi? I am assuming compression is ok (ok maybe I should not) so you have to narrow it down to spark or fuel.

R12 is still out there, a shop should be able to get the real stuff. That is what is in mine. the replacements are often some kind of hydrocarbon (propane/butane) from the research I have done. IF you cant get R12 I would suggest R134 and a replacement Condenser like a parallel flow and maybe even a aux fan. New drier and complete flush of the evap, an a new compressor just to be sure, replace everything (evap too if you want to pop for a new one). Oh and barrier hoses as well. With all new stuff you will be into the price range of a vintage air, but will not have to do the fab work, and it will be original as far as the controls. I like the OE style since it maintains the correct use of the outside air chimney for ventilation. The correct way to diagnose an existing unit would be to have a shop evacuate the existing gas (if any) then fill with nitrogen to about 80psi (the normal off pressure for todays heat) see if it holds pressure, use soapy water to find leaks esp around the condenser. Look at the connections as well. The evap lives in a safe place so it will prob be ok. if pressure test checks out, before pulling a vacuum check to make sure the little line filter at the outside firewall connection of the high side is not plugged up, Flush the condenser with cleaning fluid install a new drier, pull a vacuum. If it hold near 30inmg for several hours after stopping the pump, then they put in the correct amount of R12 (assuming no oil was lost). The system is very simple, and as demonstrated in the video works just fine. Mine had a slow leak at the condenser, I was able to get a nice NOS unit to replace it as well as a now hard to get 33286 drier. This meant I was able to get it completely original. If I could not get the condenser and drier I would prob opt for a after market condenser of the same approx. size and modify the inlet side hard line so I can use the easier to find driers with inlets and outlets at the top.

have you noted excessive play in the steering parts? IIRC the inner tie rod is only one flavor now, so if you go that route make sure you get the correct outers. What is the symptom that you are attempting to correct with the replacement parts?

A little background, there was some chatter about the ineffectiveness of the stock OE AC system, to point of perhaps still pics were showing low temps a result of pics taken in the winter time. The video was done to show the actual temp drop in real time for doubters. I generally stay out face book, but I also don't like misinformation so I felt the need to make the video. As mentioned feel free to jump around.

or not.

https://www.thezstore.com/page/TZS/PROD/23-4307 Not cheap so you would want to make sure your old ball joints are not worn out. Have to remove them, they should be somewhat tight, any slop bad, easy to move bad. If they seem ok then you could clean up (pump grease to displace all the old) wipe clean, install boot, install on car, pump up with grease unitl you start to see the boot bulge (just a bit).

they just fit over and have a wire IIRC. You would need to look on ebay and have some measurements ready to compare (they are given), I started down that road but popped for the sankie types.

look out for cheap ball joints, avoid them, moog is good, I got a "Sankei 555" made in japan. Neabour had a cheap ball joint BREAK on him Don't know the details but that was enough for me. The OE ball joints may be fine, if there are just oozing may just need a boot. IF they feel tight and have no play, you may just want to clean up and replace the boot. New is not always better.

head phones off, skip around its pretty long. Just wanted to show that the factory sys does work well, just cause its old does not mean it has to be replaced with an aftermarket unit.

If this is a swap, sometimes there are issues with shifter type and trans type. Generally manifest as not fulling engaging some of the gears. the shifter needs to be "clearance" . If the shifter is original to the trans, not an issue. I have heard some problems can happen with 240's as the trans tunnel may need to be clearance again when receiving 5 speeds.

I gotta ask, you did try shifting thru the gears before installing it right? What was the initial issue that required the removal of the tail housing?

That's how I assumed it worked as well CO, high voltage, high current, more heat open longer. did not think of if as a ambient temp sensor as well.

the oil pressure gauge itself has some kind of voltage regulation going on IIRC to deal with voltage fluctuation. Its pretty crude I think but it was something Nissan addressed.

there is a basic assumption that the block and or head is NOT cracked. So CC you had 2 broken head bolts? how did you know that? you installed the head with missing bolts? They broke during installation?

since you are going to have to re do it, you should clean head and block of any remnants of head gasket, DO NOT USE one of those abrasive 2" wheels to clean, rather a lot of elbow grease, a PLASTIC BLADE razor scraper (at least on the head, the block is less likely to be damaged by a regular metal scraper), lots of gasket remover goo etc... THEN check for flatness of he head. IF its ok carefully follow the directions in the FSM regarding how to torque in sequence and amount of torque applied in multiple steps.

so you put the head back on without fixing the broken head bolt? IF I understand that then as CO mentioned zero chance of it working right, yes oil/water leaks since clamping force is the only thing that keeps them apart.

put a cooking thermos in the rad start the car, let it warm up see what it reads, prob 185 looks fine. If the old rad looks good I would leave it, or get it rebuilt (new core) if it looks bad. a rad shop will charge you about 300$ maybe more. Lots of folks put those cheap China made alum one in there, I would not trust it. Would rather have a quality shop re do the old one.

agree with the weld a nut, you have plenty to work with, should be an easy one to weld on to. Easy out may work, but if you screw that up and snap it off it only complicates matters. Plus you really really don't want to f up the block with a drill hole that walks off and messes up the threads. No down side to the weld nut method.

funny I just watched a video moss garage IIRC and the Valvoline guy was on there talking about 1400 ppm of zinc.

this is interesting, a later model style AC evap (not the suck thru passenger side evap) on what looks like a 240 (based on the center vent). If this can be done it would be your best bet for original and functional. see the pic on post #23

If I recall correctly the evap just tacked on the fan where it sucks in air from the cabin, so I would think no dash removal required. Its this suck thru and small ducts that make it so weak. Good luck finding documentation.

Looks like my VR-1 is not so great.. But my 75 has a catalytic converter so not sure what would be best.

I presume you are working on a 240? if so then you can refurb the oe AC and it will work, but not very well (the 260-280 was much better). IF you want a good working AC in a 240 then the vintage air is prob a better option, Lots of fabrication, lots to figure out on ducting, NO venting to out side air, NOT orig which may hurt the value of the car to some collectors.

did your surface that head? it looks mighty clean.