Captain Obvious

That hose in your pic makes a whole lot more sense. That hose is the coolant input to the front carb. From there, the coolant passes through the front carb - comes out of the front and goes into the rear - passes through the rear carb - comes out of the rear carb and connects back to the hard lines at the brake booster corner of the engine. If you decide to go the 240 carb route, search around this site and the other Z sites. There is lots of good conversion info available. Will probably answer most of your questions. Not all, but most?

TomoHawk, That's too funny... Back when I was messing with AAR's, I grabbed one of those Pathfinder AAR's from a junkyard because I saw that it was held together by screws! I was considering using it on my car, but I decided against it because it's designed for a different intake manifold design. If you look at it, you'll notice that there is only one place to connect a hose instead of two hoses that are used on the Z's AAR. That single hose is the air into the valve. The air OUT of the valve comes out the O-ringed hole in the bottom and passes directly into the intake manifold without using a hose. I'm considering drilling a hole in my intake manifold and adapting that single hose style. Would remove one hose from the system and clean it up just that little bit, but that project is further down on the priority list.

Hi FastWoman, I used a lathe to cut the crimped over lip off and after that lip was removed, the the two halves just fall apart. You could use a file to do the same thing. Wouldn't be as fast or as clean of a cut, but it would work. I usually try to take pics of projects like this just in case, but for whatever reason that I can't remember, I didn't take any of this one. I was probably in a hurry to get it back on the car or something. I've been meaning to take it back off the car and take some pics of it opened up. Maybe this week as the weather isn't Z driving weather anyway, right? So if I don't have to spend the whole next week bailing, I'll take some shots for you. Anyway, I cleaned it out maybe 500 miles ago, and I have no reason to believe it needs it again yet. PS - Glad to see you active... Been wondering where you been. :ninja:

I'm not sure what hose you're talking about. If you're talking about the inch or so diameter hose in my picture here: then I don't have a good explanation for that... There should be nothing in that hose except air. If you've got coolant streaming out of that hose, then you got real issues. There are other hoses in that area that are supposed to have coolant in them, but I removed them from the car with that block off plate. The stock setup has coolant running into the carbs to heat them up, and I disabled that feature as well. Are you sure you're looking at the same hose shown in that pic?

The 77 does not have a separate fuel pump relay. Only the 78's have one of those. On the 75-77, the fuel pump is controlled by one side of the EFI Relay which is located above the driver's left knee. There are two relays in that one box, and one side powers the fuel pump. I think they might refer to that side of the EFI relay is referred to as the fuel pump relay in the EFI section of the manual, but the point is, you will not find a "fuel pump relay" in the car. As for testing it and the fuel pump... Easiest thing I've seen is to pull the small spade lug connector off the starter and then then the key to "START". The starter won't spin because of the wire you pulled off the starter, but the fuel pump should run and you should be able to hear it.

I can cut metric threads. Tell Keith if he doesn't want to risk damaging the parts with a die, I can single point some for him.

Been a while since I looked at one of these so please forgive... I'm going from memory here. There is a tiny slotted head screw with a nut on it. I believe the screw passes through the diaphragm. Under the head of that slotted screw is a small (maybe 1/2 inch diameter?) rubber washer. That washer is the seal that prevents fuel from flowing through the power valve when it's not supposed to. In other words, when the valve is closed, that rubber washer provides the closing seal. I've found that those washers either turn to dust or turn to goo. Probably because of the ethanol added to today's fuel. Basic function of the power valve: Vacuum behind the large diaphragm provides the closing force. The spring behind the diaphragm provides the opening force. The washer under the little slotted screw head does the sealing. In order to test the system without the power valve, you can cut a new round gasket without any of the "functional" holes in it and install it between the power valve and the carb body. Cut yourself a round disk out of gasket material and only put in three holes for the three mounting screws. Let the gasket disk block off the small fuel and vacuum holes. (Does that make sense?) For a more permanent modification, you can make a flat block-off plate. Here's what I did: You might not want to leave it on forever, but it helps narrow down rich running issues. If you completely block off the power valve, then there the only way fuel can get to the engine is through the main jet (or the choke nozzle, but I'm assuming that's not your problem).

Wayne, My pleasure! Honestly I'm the one benefiting greatly from this drawing and I'll do whatever I can to make it better. And no hurry on the next rev. Maybe other suggestions will come up. You'll never tell.

The pressure in the cooling system will always rise as the engine warms up, regardless if there's a head gasket issue or not. How do you differentiate between a normal rise and a head gasket caused rise?

The only thing the brake relay will do is turn the brake warning lamp on as part of a "lamp test". Having it unplugged will have no negative effect on anything else. I don't know anything about the alternator upgrade.

I guess I wouldn't change the title of this thread. Wayne's color diagram is for the 77, but all the 280 years are pretty similar. I'm not sure what do you mean about not being able to find files for the other years? If you're talking about color wiring diagrams, then I've seen two of them... The 77 that is the main topic of this thread, and another one for 78 that is nice, but not as complete as the one for 77. Other than 77 and 78, I've not seen anything color. For 75 and 76 I refer back to the standard version in the FSM.

Haha!! Somehow I just knew you were gonna say that!! :laugh: I didn't spend hours and hours on the ignition relay issue. It was clear that it wouldn't work right as shown, and since there was a blank terminal and another sharing two wires, it was pretty easy to figure out what happened at the drafting board. Most surprising to me is that Datsun never caught it even after four years. Also, a peeve I've got is them calling it an "Ignition Relay", when it really has nothing to do with the ignition system at all. It would be more properly called the "Ignition Switch Relay" or "Ignition Switch Position Relay", or something like that...

Thanks for the merge E. I was trying to decide if I should have started a new thread for the ignition relay issue or if I should just add on to this one, and I decided that I would start a new thread because ignition relay issue pertained to all the diagrams from 75-78, not just the color 77 version. I wasn't sure that someone looking for 75 info, for example, would pay that much attention to a thread that seems to be mostly 77-centric. It was 51-49 to me... However, I was also going to put a note in this thread as well when I got the chance, because I turned up a new issue with the color dwg. Simple oversight due to blurry dog-eared original hardcopy. There is a mis-numbering of one of the fuel injection relay connections: And some minor formatting slips as well. I love that color diagram...

Haha! So what else do you have that you're keeping all to yourself? Thanks for the info on relay options. Could come in handy in the future, but thankfully there's nothing wrong with my relay at this time. The car works fine... The diagram doesn't. I've got some projects planned for the future, but at this point it's just wishful thinking and exploration.

After much tail chasing and confusion, I turned up a mistake on the wiring diagrams for all the fuel injected cars. The problem is in the operation of what they call the "Ignition Relay". Here's the section of the diagram that shows the ignition relay, but there's a problem: You need to do this: Here's how the drawing should look: And for those of you that haven't glossed over with disinterest yet, here's what the ignition relay is supposed to do:

The CSV operates on full B+, as does the thermotime switch. (Ignoring relay and switch contact drops of course.) Neither the thermotime switch or the CSV get's any power at all unless the key is in the "START" position. The thermotime switch will open from engine heat OR it's internal heater, whichever reaches trigger temp first. (Haha. That's my zombie input. :ogre: )

Yeah I was worried about that. I guess I'm not surprised... Especially when it comes to something "safety" related. I'm sure there were changing regulations and test procedures as well as constantly advancing research, understanding, and technology.

Yup. From what little I've heard from others, that's the typical failure MO with the flat tops. They fail rich more often than failing lean. There are lots of things that can cause them to run rich, but not all of them will be addressed by rebuilding the carbs. Depends on what's wrong. If the problem is with your float levels or your power valve, then you stand a chance that it will be better when they're done. If the problem is with the needle or the nozzle, then you're scrod. You can (and should have already) checked the bowl levels yourself. I assume they're OK. My theory would be that you lodged a goober in one of your power valves when you were doing full throttle donuts. Now the goober is making it stick partially open all the time and dumping fuel into the engine. You might see if the garage would rebuild the power valves first before they took the carbs completely off the car. You can get the power valves off the sides of the carbs while the carbs are still on the manifolds. You have to get a bunch of plumbing out of the way to get access, but it's the same plumbing that would have to come off anyway if they were to pull the carbs completely. They could also use a flat plate of metal to completely eliminate the power valves if they wanted to try that. You would lose some full pedal performance, but it might narrow down the problem area. I'm sure the garage wouldn't be interested in either suggestion, but it's just a thought. :bulb:

Excellent. Glad that the pics help. There was one other pic that I forgot to talk about, but it's so simple that it probably goes without description. However, since I already took it... Here's what the main bracket looks like with the take-up reel removed. They used plastic bushings on either side of the take-up reel. Don't lose them. Also, for those of you that are having latch mechanism issues... Can you tell by looking at the pics how the centrifugal latch is supposed to operate? If not, I can annotate one of the pics to explain what happens when you try to pull the belt "quickly" off the reel and invoke the belt latch.

Here's the pics I took of my seatbelt disassembly. First, a caveat... I didn't take these pics with the intention of using them for a how-to... I just had a dead belt with badly frayed webbing and thought I would take it apart to see how the whole thing worked. I figured I would take some pics along the way so I could refer to them again in the future if I ever needed to. Second, these pics are from a 77, and I have no idea if they are the same on other years, but hopefully they will add some value. I also have pics of the assy before I popped off the side covers, but I'm not including those since we all know what that looks like. Step1 - Wind the seatbelt as far as you can into the retractor assy to minimize the tension in the retractor clock spring. In other words, let the retractor spring pull in as much belt as it can before you loosen the side cover. Once you have the belt fully retracted, use a small screwdriver to pop off the side cover. Note that there will still be some spring tension so be careful. Do not let the side cover spin wildly after you pop it free. Hold the cover with your hand to make sure it does not spin and after you get the last retaining pin free, carefully rotate the side cover to release the spring tension. Count the number of turns it takes to release the tension so you know how many turns to wind it up when you put it back together. Interesting to note that the retractor spring function is completely separate from the rest of the assy. That means for those of you guys with retractor spring problems, all you need to do is pop off that one side and replace the spring. You don't have to mess with the latching mechanism at all. In fact, for the shoulder belt portion, you probably don't have to take the assy out of the car. You can probably do that with the assy still attached to the strut tower. Here's the retractor spring and cover after releasing the spring tension: Step2 - Pop the side cover off the other sire. Here's the latching mechanism side: Step3 - Pry off the little support arm: Step4 - Pry off the latching mechanism: Interesting to note that there isn't a whole lot that can go wrong with the latching mechanism. Probably the simplest thing that can go wrong is the tiny release spring can come off or break and then the latch will operate too easily or will not release at all. Step5 - Pull the retaining pin that holds the take up reel into the bracket. Look down into the belt reel and you will see a retaining pin. Here's the pin fully installed: Here's the pin pulled halfway out: Here's the pin pulled all the way out: Step6 - Pull out the center axle shaft and the take-up reel will come free. The belt is held into the reel by the center axle, so once the axle is removed, the belt webbing can be removed from the take-up reel: Reassembly is the reverse of disassembly.

Gotcha. I'll go along with that. They could do that for even less than $1.29!!

Mike, Thanks, I got it now. EScanlon is right in that it is caused by the fact that the numbers and shift pattern are molded and have height to them. Those shadows are actually white paint on the sloped sides of the raised numbers and lines. From looking at the pics that EScanlon posted, it appears to me that they molded (or maybe vacuum formed) the black part out of black plastic and then painted all the white features on by hand. Then they potted the top part in a clear material. I wasn't there when they made that thing, but here's what I see happening... First they mold the black plastic disk. Then they fill (inlay sorta) the outer two rings with white paint and wipe or buff off the excess resulting in a quality edge. Then they paint the raised letters. Then they mold the top dome in a clear acrylic or epoxy. All for about $1.29

Mike, What are "drop shadows"?

I took a quick look out there for documentation available and found some people selling manuals for the KP-8005, but nothing free. I would agree with your power wiring assumptions (red and black), but I'm not so sure of the speakers... Power antenna outputs weren't all that common in 77, and I have no idea if your 8005 has one. Two of those three unidentified wires are clearly speaker left and right, but the third unidentified wire might be return for the speakers. It depends on how they designed the output amp. They might return the speakers to ground (black) or they might have used a floating return from the speakers on one of those three unidentified wires. And the problem is it might cook it if you hook it up wrong. You can hope someone here knows old Pioneer or you need to buy a manual. I could tell you for sure if I opened it up and looked at the guts, but I don't want to try to get into that remotely. I might be able to help you verify if one of those three wires is truly an antenna control with some simple ohmmeter tests if you're proficient with one of those. :bulb: Hopefully someone here knows old Pioneer... :classic:

Thanks again Mike. Do you have any insight into the timeline for those two alternators? In other words, was one of them the first version and then then they switched to a different version, or were those two varieties both available at the same time on different cars?