Captain Obvious

My Z came to me with the "racing style" door mirrors, and like so many others before me, it fell apart because after years of adjustment, the ball stud pulled through the hole in the adjustable shell part. This left me with the shell housing part completely off in my hand and the mounting half still attached to my door. So with nothing to lose, and for the trivia, I figured out how it originally went together. First, I took the mirror off the door and disassembled it. Looks like this: Typically like so many others, my failure is that ball pulled through the hole: But the tricky part is... How do they get that spherical ball stud installed in the first place? The whole mirror assy operates on the principal that the ball is supposed to be larger than the hole in the mirror body and NOT pull through. So after twisting (even twisting with heat) did not work, I discovered that it is simply splined and pressed together. Duh. Like this: To assemble, you put the ball stud through the mirror body like this: And then press the ball stud into the mounting arm: Of course, mine is going to pull through again, but it opens up some repair avenues like putting a steel washer behind the original stud or making a larger stud. And of course, the trivia.

Haha. Yeah, mine (like so many other parts on my car) was bead blasted by the PO. Looked great for a week and then started to rust because he blasted off all the plating. The plan would be to eventually have a batch of parts replated and chromated.

mgood, That reminds me... There's a story about the whole reason I even ever noticed the difference between the different ashtray designs. It goes like this: I use the ashtray not for ashes, but as a small storage compartment for change, etc. I also put my cell phone in there, but it didn't fit quite comfortable, and I decided that it would be better if the "snuff out shelf" wasn't in the way. With that in mind, I unscrewed that shelf from my ashtray and used pop-rivets to re-attach the spring retainer on the outside of the tray. After doing this mod, I did find it easier to get stuff out of the ashtray, but I discovered a problem... Without that shelf in there to grab on, the ashtray was difficult to get out of the console. There's nothing to hook a finger tip under. It looked like this: I was content with the trade-off of more space for the phone, until... I came across an OLDER ashtray with the little grabber handle that I had never seen before. So, I undid my previous pop-rivet mod and moved the little grabber handle from the older ashtray over to my newer style with the light window. I used slightly larger screws and tapped the grabber handle for threads. Looks like this: And here's the inside with the handle installed. Now I've got the best of both worlds... No shelf in the way, but a little lip to grab onto to pull the ashtray out of the console: It's the little things....

Hahaha!!! :laugh: Thanks for the laugh!

Haha! Have you ever considered brain surgery, Mr. Gumby?

I found it. Page CL-9 of the 78 manual... Top right: (Or CL-8 of the 77 manual. I didn't look earlier than that, but I assume they're all the same.)

That is not the case. (Get it? Not the case?) Nevermind. They are NOT grounded through the case*. In fact, they were very careful with their grounding scheme, and while the case is in fact grounded (by virtue of being bolted to the body), there is no electrical connection between the case and anything inside. All of the grounding of the ECU electronics inside is done through the EFI harness wire connections. *I've not messed with years prior to 77, but I assume they're all the same in that regard.

I agree. The threads aren't tapered, there's no way I would want the steel shoulder of the hose end fitting trying to dig into and seal against the body of the slave cylinder. I think there's supposed to be a somewhat malleable washer in there. As for that washer in the pic, I think it's a typo. I think they showed it at the wrong end of the hose. There's absolutely no reason for it where they have it shown. The end of the hose is held in place with the typical clip-in-groove, and the sealing is done by the flare on the end of the hard line. The only thing a washer would do at that end is get in the way of the two flats on the hose fitting that are there to keep the hoes end from turning as you tighten the hard line. :bulb:

I believe the carbs you have are from the HJL38W series. The SSS 1800 is an engine designation, not a carb designation. It's a high performance version of the 1.8 liter engine available on some of the Datsun models of years gone by. They are a significantly smaller bore than the Z carbs (38mm as opposed to 46mm). I'm not sure you could get enough air through those carbs to feed a 2.4L at WOT. Maybe, but would require some testing.

No worries. Thanks anyway. I just couldn't really picture what you were talking about there and I wasn't sure if the stuff you found was: a) Factory original weirdness Age and heat related insulation degradation weirdness c) Modifications from a previous owner The reason I'm asking is that I've been messing around with the FI harness myself lately (on my 77) and I'm wondering if I should dig in and look for this kind of stuff: I have stripped the harness back just a little in some spots and know what you mean with way they "pre-group" some of the wires based on their ultimate destination. But I've not found anything weird like that...

Thanks for the pics. Better than before, but nothing like taking one apart! I just want to make sure I'm interpreting the pics right and then I'm going to get out of the way of the experts... So they use needle (roller) bearings on the shafts? The bearings are "sealed" according to the parts list, but in the picture, I can see what appear to be the ends of the roller needles. So, is the seal transparent or non-existent? I also see on the diagram that there are O-rings inboard of the bearings and I assume that's to seal engine vacuum? Am I interpreting this stuff right?

Look at the bright side... You inadvertantly also verified that your AAR is working properly.

They redesigned pretty much all of the unseen sheet metal for 77. I haven't checked, but I would be very surprised if he could use any tank prior to 77.

Not sure... My 77 has no such wire. Have you got a pic?

I wish I could add some Weber specific input along with Blue, but the only thing I know about Webers is that they're carbs... I've got some Mikuni (motorcycle) experience, and they've got similar "progression" holes. The only thing I could add that might be applicable is that the more closed you can get the plates at idle, the better. A lot of the problems I see people having with the bikes idle is that they're not truly running on the idle circuit. The bike is running so crappy that the only way they can GET it to idle is to crank the TV open and expose the holes. And I've been surprised on just how closed you should be able to get the plates for idle. This applies to the z car carbs as well.

Probably never showed them here. Basically I modified a set of round tops so I could drop them "plug-n-play" into my 260 without messing with external return springs, linkage changes, or different heat shield arrangements. Here's a couple pics. The whole story is over at zcar.com. - ZCAR.COM - Round Tops Customized Drop-In Replacement For 260

Cool. Was a shot in the dark just hoping it might ring a bell. I had a hard time convincing myself that vacuum had anything to do with it. I kept telling myself that the vacuum force on the butterfly should be balanced. As much force should be pulling on the top trying to open it as pulling on the bottom trying to close it. So I started looking for some other non-balanced phenomenon and ended up with the gummy steel to gummy steel theory. It's still a theory, but one that I have experimented with a little using a shop vac and blue marking dye. I can pull just enough of a vacuum with the shop vac to get it to show up a little on the bench. So, I would be a little disappointed if you've got enough wear to cause this kind of issue after just 2000 miles though. Makes me think it should be something else. Did you ever see my round tops with the integral return springs on the shafts? Did I ever show them here?

Let's hope that you did in fact find the root problem. Do you have any pics of the stuff you found when you unwrapped the FI harness?

I would not add any grounding wire to the EFI system without very careful consideration. Pardon the geek based thread jack... the ECU is a precision analog system which does some of it's signal processing at very low levels and Bosch (who I assume was pulling the strings at Hitachi) paid careful attention to where the ground currents are flowing. When you're acting on analog signals, current through any resistance (including resistances to "ground") cause voltages to occur where they might not be wanted and this can cause errors in the system. For example... They were very careful to segregate the injector current from all of the other currents flowing through the system. They were also careful to create their own ground connection for the AFM and air temp sensor. On paper, all of the grounds are connected together. And with an ohmmeter, that truth can be verified. But... just because they show as connected, and measure as connected, doesn't always tell the whole story. You don't want the headlight current flowing through the same ground that the temperature sensor uses...

Haha! Excellent! So in light of the additional info, I believe that those ring terminal grounds do NOT come from the EFI harness and I stand by my original claims: How do I know? Why do I care? Because my PO messed with the electrical system on my car, and I've spent some time trying to piece it back to the way it should be. And this thread is helping me a bunch because I've long known that he messed with the wiring up around the coil and AFM. Not quite sure yet exactly all of what he did, but I know it's not right. My car currently does NOT have a ground strap on the AFM, but I've got this misplaced ring lug groung coming off on one of the timing cover mounting bolts? I also have a completely unused foot long piece of wire with empty ring terminals on both ends (obviously is supposed to be a ground somewhere). I don't know where this stuff is supposed to go, but this thread is helping. So, keep discussing!! Please! And mgood... I third the comments about the beautiful engine compartment!!

Don't know if it's applicable or not, but I just went through something very similar with the butterfly on my FI throttle body. No linkage connected, blip the throttle, and doesn't always return to idle. Worse if you hold it above idle and then release it slowly (instead of a "blip"). Most interesting thing about mine was that it only did it when there was engine vacuum present. With the engine not running, it always snapped hard clean back to the adjustment screw stop. I think I have tracked mine down to worn through hard chrome plating on the throttle shaft which has exposed the gummy soft steel underneath. This soft steel of the shaft does not slide well against to the soft steel of the sleeve bushing pressed into the throttle body. I believe this soft steel to soft steel contact only occurs when engine vacuum pulls the butterfly towards the intake manifold and that's why it doesn't do it with the engine off. In the end, I wrapped my return spring another wind around the shaft and called it a day. Doesn't fix the problem, but seems to fix the symptom. If it gives me any more trouble, I'm going to mount hardened bearing surfaces on the shaft and maybe swap out the soft steel bushings for acetal. Anyway... Way too much about me... So does yours only stick while the engine is running, or is it at all times?

Actually... looking at the photos again, I want to enter an appeal... In mgoods photos, there are what appears to be TWO wiring harnesses going under that cable clamp near the AAR. There is a large diameter harness (which is clearly the EFI harness), and there's a small (1/2 inch) harness laying on top of it. That ground ring terminal connection actually comes out of the SMALL harness, not the EFI harness. So where does that other harness go? Does it actually tie into the large EFI harness somewhere out of frame, or is it in fact part of the engine bay harness and NOT the EFI harness. And what about the one at the AFM? Does that ring terminal actually emanate from the EFI harness, or does it come out of the bay harness? Huh? Huh? I'll take my lumps, but I want to double check first!

Haha! Me wrong? Completely plausible. Probable even! mgood's photos clearly show ring terminal grounds. :embarrass: I believe I have generalized and incorrectly assumed similarities between years. Please forgive me... Here's some input for my defense: 1) That ring terminal connection to ground near the AAR is not shown on the 76 wiring diagram. 2) That ring terminal connection to the AFM is not shown on the wiring diagram either. 3) I've got a 77 and I have verified that neither of those ring terminals exist on the 77 wiring harness. 4) My statement about ground connections holds true for 77. Unfortunately we weren't talking about 77! Do I get special dispensation since even though I spoke incorrectly due to my over generalization between years, I did nail the root cause of the problem!

I don't believe there are any "chassis" earth connections in the FI harness. I think the only connection to ground is that big wire which connects directly to the battery. From that connection, it splits within the harness to branch out to "provide a ground connection" to a bunch of locations within the system, but that sole connection to the battery is the ground for the whole system. There are no ring lugs coming out of the EFI harness, and the metal ECU case is not electrically connected to the circuit. Basically, if you have a problem with that main ground connection to the battery, there is no other backup which can share the load. And unless I'm missing something (which is completely possible!), the car will not run. That said, it's absolutely clear that you've got some kind of intermittent connection issue, but I don't think it's a grounding problem. The thermotime switch should be completely out of the picture unless the engine is cranking, so I wouldn't worry about that. Same goes for the CSV. Once the engine is running, the CSV is doing absolutely nothing. The AAR changes too slowly to react as you described. Even if you would disconnect it completely, you wouldn't see any effect for fifteen seconds or so. That leaves the temp sensor... If you have a shaky connection to the water temp sensor it will cause exactly what you're describing. Basically, if you open circuit the temp sensor, the ECU interprets that as an extremely cold engine and dumps in lots of extra fuel to account for the low temperature. If, by wiggling the wires, you are breaking the WTS connection, the engine will stall because you're flooding it.

Well I got a pretty good idea what you're going to be doing tomorrow. Don't tease Murphy... :laugh: