FastWoman

Well, I'm not quite finished, but I've made progress. (Life gets in the way.) I've got the MaxiFuse blocks installed. That was of course the easy part. The harder part is sorting through all the crusty, corroded bits of wiring harness and rebuilding the high-current parts of it. The ground line, which appeared to be about 10 ga and bolted to the block under the front heater hose clamp, was crimped in multiple places to branch lines. I pulled all that apart and replaced the wiring with 10 ga. crimped connections that I've sweetened by soldering. The alternator wiring looked worse. It, too, was 10 ga, fused at 80A (!!). It had multiple crimp connectors that were crusty, corroded, and burnt. I upgraded to 8 ga, thin-insulated, teflon ensheathed wire, crimped and soldered, with the same wire running from the + post on the alternator all the way to the MaxiFuse block. I found that copper tubing made a great crimp material. Just pinch it with vice grips, and it snugs right up. Then infuse with solder, cool, and tape. I also made the lug at the alternator post out of 3/8" copper tubing. I put the 8 ga main line, a new 16 ga line with a bullet connector on it for the condensor, and the branch line to the field coil connector inside the 3/8 tube. I then crimped, soldered, flattened the end in a vice, and drilled a hole for the post. I finally put a piece of heat shrink around it. It looks great and is 5x beefier than the OEM. With this wiring, I was perfectly comfortable upgrading my fusing back to 80A. (I had previously downgraded to 60A, but upon seeing what horrors were inside the wiring tree, I think the wiring wasn't even competent to handle 40A.) I took out the 10ga +12 wires and their branches from the starter lug to the fusible link assemblies and from the battery post to the two EFI fusible links, and I replaced it all with a 4 ga cable from the starter to the MaxiFuse block. The branches of the original lines were crimped and crusty, albeit not burnt. After getting the new fuse blocks put together I went to start the car, and it wouldn't start. I quickly found the problem. The fuel pump wasn't pumping (again!), and the problem was in exactly the same spot. I jiggled the offending wiring harness connector at the firewall, and the fuel pump came to life. Engine runs, and everything is happy. I've decided to break that one wire out of the large connector and to use a bullet connector instead. I don't want to have to be jiggling connectors every time my engine doesn't start! Along about this time, the mosquitos and gnats were swarming again, so I had to call it quits. I'll do the headlight relays tomorrow and hopefully get the updated wiring tree all taped back together. This project has gotten more involved than I wanted, but at least I've resolved several trouble spots before they had a chance to become trouble. It all looks very nice too, of course.

Check with junk yards? Failing that, there's nothing wrong with "stitched together." Isn't that what Nissan did -- stitch it together? If you want a top-notch job, find a sailmaker or someone who makes biminis and covers for boats. Either that, or find a good upholsterer. These people all do some incredibly fine work. They could even do the quilting pattern on the earliest Z's. I bet there are some good sail/bimini/cover shops in Portland.

Fixing a dieseling problem is somewhat mysterious. It happens when compression is too high (from a lot of carbon buildup) and/or when there are tiny parts in the combustion chamber that glow hot enough to keep igniting the fuel/air after the ignition is cut off. I *think* your choice of spark plugs can do that. There are 3 types of NGK plugs recommended for my '78 -- the B5ES-II, B6ES-11, and B7ES-11, being hot, medium, and cold plug types. You might try the colder plug rating (?). As I recall, the 240's use the projected plugs (e.g. BPE7-11). There are also some products touted to burn/clean carbon out of your cylinders. I have no idea whether they work. I've also gotten advice from an old/experienced mechanic to mix 1/2 gallon of diesel fuel in with a full tank of gas to burn out the carbon. I was a kid at the time and did this without questioning it (on a Toyota Celica). I got some very funny looks and a strong warning from the service station guy. The car ran OK on the mixture, and it didn't seem to make any difference that I could tell with regard to the carbon. I've also heard of the old-timers throwing handfulls of rice into their flathead engines to knock out all the carbon. I DON'T THINK I'D TRY THAT!! But that's what they did. I'm just guessing that this problem has a longer-range fix, seeing as it took a while to develop (assuming carbon). I think the most important thing is to determine why your engine is building up so much carbon and to make sure it is running as cleanly as possible. I think the engine might eventually burn off all the built up carbon that way. Perhaps it's running too rich? What do the plugs look like? Good luck!

I thought you meant the caps on top of the towers. You should be able to find vinyl material at almost any fabric store and cut it to shape. Know someone who sews? You can also repair vinyl by sticking a backing to it with vinyl adhesive, and then impregnating the rip area with new vinyl under a textured mold. If done carefully, it can actually look pretty good.

I assume this is a carbureted engine? Does it run normally when it does that, or does it sort of sputter and run in surges until it dies? If it's the latter, it's "dieseling," probably from carbon buildup in the cylinders.

Mike, you can try a hardware store or, better still, an electical supply store. FAIW, I've been working with electronics for about 35 years now, and I've never known a solder connection to fail from vibration. Heat from electrical current is another matter. Rather than to crimp "into" the wire, you can squeeze the tabs *around* the wire and then sweeten the connection with solder. That will give you maybe another wire size from what the connector is designed to handle.

Wow, and I thought *I* had coordination issues! How'd he manage to do that? Consider sanding the back side and epoxying some additional material to it.

Hi Chuck, While you're into the wiring harness, you might want to wire the headlights with relays to offload the high current from the combination switch. To do this, I bought a couple of Bosch-type relays with matching plugs for a total of about $5. Your price might be a bit higher, as I ordered 10 off of Ebay. Here's a somewhat messy diagram of the mod I'll be making. I'll basically be inserting the two relays in the path by cutting the headlight wires in the wiring harness and wiring to relays that I've mounted in the relay housing. BTW, there's just enough room in the bottom of the relay housing for the two relays, mounted with the plugs extending downwards.

Ouch! Well, I live off the water and park my car outside. The fuse block also sits right under the righthand hood vent. Great combination, eh! On the other hand, all of the connectors are gold plated. (Were yours?) That should help a bit. I got a couple of Bosch type relays to re-do the headlights, while I'm into the wiring harness. The four headlight wires course right along the same section of harness. I'm going to interrupt the lines to drive two relays (mounted in the relay housing, of course) -- one for low beams, and one for high beams. I'll then use the relays to switch +12VDC to the outbound lines, with the common connectors running to ground, rather than +12. The source of the +12 will of course be the headlight fusible link. This solution won't give me independent fusing for the two sides, but I can't imagine that's so important anyway. Anyway, I ran out of light and was getting bit by mosquitos. The saga continues tomorrow.

Hi Wayne, That's a nice solution! I have my Stinger blocks, though -- more blingish, but I don't think that's a bad thing. I'm going to mount them on an aluminum rail bolted to the relay housing. I finally unwrapped the wiring harness and extracted the battery-side wiring back to the starter. That's some crazy looking stuff! I had to put it down but will finish the job tomorrow (hopefully). While I was at it, I spray painted the vacuum bottle and bracket with black epoxy spray paint, then gracefully dropping the vacuum bottle in the dirt. After cleaning off the dirt-encrusted spray paint and re-spraying, I think it looks very nice. I'll be spraying the relay bracket too, of course, hopefully without the intermediary step of encrusting it with dirt. I'll post pics when I'm done.

I presume these are "Great More" locks. I had the same problem when I replaced mine. I had ordered my locks before cracking open the door to remove the old ones. (Of course!) I did tell the seller that the arm configuration didn't fit my '78, but I doubt that impacted the claim that it fits all S30 Z's. Anyway, your solution sounds better than mine; however, if you or anyone else is interested in my not-so-pretty solution, I simply beat/bent a piece of steel around the arm of the lock, punching a dimple into the steel over the hold in the arm, to keep the extension from slipping off. I then bent the extended arm and fashioned a "finger" to slip into the square hole on the lock. It's not pretty, but it works just fine, and it's also easy.

Well, that wasn't a question to you specifically, but to others in general. I do (very much) appreciate all the information you've given me! Thanks for your help!

Thanks, but something is amiss. The Nissan brown links must depart from normal color code standards. The brown is lighter gauge than the green, at least on my '78Z. I think I'm going with 30A. If you compute ratios between the black and green, the green is 125% of the ampacity of the black, when adjusted down for cross sectional area. If you apply the same 125% when adjusting down to the brown from the green (i.e. taking the ratios of their x-sec areas, times green amps, times 1.25), then you get 30A. I finally looked at the schematic for my headlights. It seems one of the fusible links is already devoted to that, so I guess I'll still have a spare fuse position. My current plan is to wire the headlight socket output to two relay coils -- one for high beam, and one for low. I'll then run a wire in parallel off of the headlight maxifuse to the respective relays, with the output running in parallel to the high and low beam filaments, with the center connector grounded on each. Thoughts, anyone? Finally, I'm guessing this is the lineup of the fusible links in my '78. I think I would know so much more about what I'm doing if the schematic foldout hadn't been ripped out of the FSM that I bought: All color codes -- W towards battery, W/R towards circuit 1. Headlight (brown?) -- runs to combo switch, and then to headlight bus of fuse block. 2. Battery (brown?) -- runs to bat bus of fuse block. 3. Battery (brown?) -- runs to the ignition switch. 4. Ignition (brown?) -- runs to ignition relay and then ignition bus of fuse block 5. Accessory (brown?) -- runs to accessory bus of fuse block 6. Alternator (black) -- runs from output of alternator to + of battery 7. EFI (green) -- runs to EFI main relay and then to drop resistors for injectors 8. EFI (green) -- runs to EFI main relay and then to EFI control unit So that's 8 circuits total, and there are 6 fusible links. That would mean that two of the circuits from 1 through 5 are really part of other circuits and are simply diagrammed redundantly on in the various pages of the FSM. If I had the fold-out schematic, I'd know which ones. I guess I can trace it all out, but can anyone help me with this one of the top of his/her head? Also are my fusible link color codes correct for the circuits described? (Nissan wasn't kind enough to provide any useful info in this regard in their FSM.) Thanks! Sarah

Er... Sorry to have rekindled an old argument. Personally I'd have no issue with keeping the fusible links, if it were not for the fact that they are crumbly, and one of my assemblies is literally hanging on the ends of the wires, due to the broken base. My contacts are corroded, a couple of the fusible links have gotten toasty enough to scorch and crack the rubber insulation, and one of my connectors fell apart (although I put it back together). All in all, I don't know whether I can depend on what's there to keep me running. I'm reminded of when I learned what a fusible link is. It was when my '75 model died in the middle of a highway U-turn and I had to have it towed. I had bought the car at 8 years of age (the car's, of course) and replaced the crumbled cover at that time. The fusible link deteriorated a couple of years later -- about age 10. Now my '78 is 30 years of age and in somewhat more frail condition than my '75 was when it was a mere decade old. I just don't trust those dangly, crumbly things. So as much as I hate to go non-stock, the mod will be happening -- probably over the next couple of days. Regarding the other mods, there's no need to upgrade to an internal regulator system, as I already have that. However, I'm thinking about wiring my headlights to relays to offload current from the combo switch. When I switched on my lights the other night, they didn't immediately come on. It took a jiggle or bump (?) before they spontaneously lit up. Other than that I've not had problems. Anyway I have 6 fusible links, to be housed in 2 4-fuse blocks. The 7th position will go to a 30A fuse to the stereo (currently in an inline fuse holder), and the 8th position could supply the headlight relay. So can anyone confirm the amperage value of a brown fusible link? 30A?

Chuck, the more ordinary variety of fuse is for lower amperages, perhaps up to 30A max (?). The maxi fuses are larger and are for higher amperages. Most importantly, they have more substantial connections capable of handling higher currents. I did finally order a couple of Stinger units. They are indeed a bit "blingish" -- really very pretty, with heavy polycarbonate construction, gold plated contacts, etc. They're more massive than I thought they'd be. Mine, the Stinger SFPD4MAX model, has a base measuring 4 1/4" x 3" and is 1 7/8" high/deep. It completely encoses the fuses. (I hope that's not a problem for heat.) If you wanted something more subdued than the clear polycarbonate housing with the yellow and black "Stinger" logo on the cover, you could always disassemble the unit, spray the plastic parts with black plastic spray paint, and reassemble. I don't think bling is a bad thing, though. ;-) What wasn't clear from the product info is that this panel is not divided into separate circuits. The left-most connections are ALL interconnected and lead to the battery post. The right-most four connectors are independent. I'll be unbundling a bit of wiring tree to see how to make the conversion. The schematics indicate all the fusible links just lead to the battery, but the wiring harness has separate leads from the battery for each circuit. I somehow missed the ampacity ratings of the different colors of fusible links, as provided in links given above. (Thanks, guys!) I'm still scratching my head about a couple of things, though: black is for 80A?! Seems kinda high. I think this line is for the alternator. Shouldn't I drop to 60A, which is the alternator rating? Brown is not listed in the table on the web page Tomo linked to. It has a lower ampacity than the green, being a smaller cross sectional area (brown being 0.3mm^2, and green being 0.5mm^2). There seems to be some use of red ratings in place of brown, perhaps because of color confusion. However, this would be incorrect. I've seen references to the brown being 30A, which is the same as pink, but obviously not colored the same. Has anyone figured out the brown? Thanks!

Cost would depend on how pretty you want the repair to be. I would think that any competent body shop could weld a patch into the area. Just ask for a few estimates from different shops. (It's hard for me to predict how much a job costs anymore. I've seen a tiny 6" scratch on a pickup quoted at $4000 and a mashed in fender on a Lexus quoted at $500.)

If you can change your brakes and rotors, you can probably change the injectors. Ordinary tools. Prices of injectors vary a lot. I asked a Nissan mechanic about my ancient injectors, and he said they rarely go bad -- just need to be cleaned from time to time. The most common failure mode is that they leak.

FAIW, I had a welder weld the cracked metal (from metal fatigue) around the door hinges of an old truck. He insisted the repair might be a bit distorted and might not hold up. I told him to give it a whirl anyway. The repair was great and held for many years until I sold the truck. Rivets, being made of aluminum, can present a different problem -- corrosion against the steel.

My '78 came with a defunct Sears unit that I had to pull out. It had a sensor near the drive shaft to measure speed, a vacuum servo mounted to the battery tray and connected to the throttle via a cable and bead chain, a clam-shell control circuit that was hidden in the innards, and a defeat switch that was chained to the clutch pedal. It seems there should have been a switch on the brake too. The installation wasn't too messy. FAIW, I had a cruise control on my 5-speed Z3. Very nice, ergonomic design. I used it very routinely, even at lower speeds, so as to avoid creeping upwards in speed in my well patrolled part of town. I suspect someone in an antique car might catch less grief about speeding, even if the car is a sports car. "Do I know how fast I was going? Oh gee. Honestly, my speedometer has been reading a bit funny for the last few weeks. I think I finally tracked down a good source for a refurbished one. It's been on order and is being refurbished as we speak."

Wow, this is an old thread indeed. I'll just add my 2c. If you want to check a rubber seal (e.g. the hatch) to see if it really closes, use strips of paper or plastic. (Tyvec is especially good.) Lay them across the area that should be sealed, and close the hatch. Then, one by one, pull gently on the strips. There should obvious be a healthy resistance. If not, then the seal isn't closing. This method worked great for finding and adjusting out leaks in my Z3's ragtop.

I might not have been using the right terms. My understanding is that "half shaft" refers to the entire assembly, from U-joint to U-joint. What I grabbed, according to my FSM, was the sleeve yoke. I gave that a light twist back and forth and felt the play I described. For me to be able to rotate the sleeve yoke with the wheel stationary, I would have had to have slop in the outer U-joint and/or the spline at the very least. The slop on the other side would have to be collectively just as much, combined between the inner U-joint, the differential, and the U-joints and spline on the other side. Anyway, I agree that there's no harm in removing the shafts and examining them for wear before buying the replacement shafts. No worries about drag racing!! I'm not a particularly fast driver -- much too old for that.

Thanks again, guys. Ezzzz, I'll eventually get around to dropping in on Tidewater Z. However, I'm still in DIY mode. There are a lot of items that definitely need addressing on my car that aren't over my head, so I'm going to keep chipping away at them as free time presents itself. Then after I've fixed what I can fix, and after I've blown out enough cobwebs that I have a more or less normally running/operating car, that's the time to explore the issues that are beyond my expertise. Anyway, Todd is definitely on my "to do" list. Jon, I think you misunderstood about my U-joint diagnosis. The weight of the vehicle was on the tires/wheels, which weren't turning even a micron. So if I was able to twist my half shafts back and forth that much, then there was definitely play in the half shafts. There may be more play elsewhere (probably is), but I think it's reasonable to conclude my half shafts are in need of retirement. After some much needed rest and relaxation in a scenic scrap yard resort, they will go to scrap metal heaven and then on to their next lives as cheap chassis for Chinese consumer cr@p. To deny them this transition would be to interfere with the natural ebb and flow of the universe -- very bad karma. Speaking of Chinese products, any opinion on the Chinese lifetime-warranted CV shafts? BTW, you refer to my "LSD," but I had assumed my R200 was only a conventional differential. Were they installing limited slip units in 1978? Maybe you're confusing my differential with ezzzzz's quaife-equipped differential? (I confess I don't know what a quaife is, but I'm guessing it's something to do with an LSD.) Were all the R200s LSDs, or just some -- or is that just a mod, like ezzzz's?

Mitchell, I went with the specification the auto parts store looked up -- pretty sure it was 75/90. Jon, I had the car's back wheels parked on ramps while I was working in the fuel pump area -- not jack stands, but ramps, with the weight of the car supported via the tires. I reached up, grabbed the half shafts, and wiggled. I didn't measure the play, but I'm guessing there might have been even 1/4 of slop when twisting back and forth -- at least 1/8", I'd say. I'm sure much of it was from the U-joints, but also the splines -- and probably even some in the differential. I probably should have taken more time seeing what slop came from where, but I was being attacked by a squadron of mosquitos and was in a big hurry to get the car done. Anyway, I'm pretty confident the half shafts need replacing. I don't know about the bushings. I remember looking at the strap over the front differential mount and thinking, "how odd." Nothing seemed out of place, though. The bushings on the moustache bar looked fine. I should have spent more time diagnosing but didn't. Probably next weekend's job.

After a bit of research, I ran across... http://www.zcar.com/forums/read/1/1872826 Apparently Hyundai and 2nd generation RX-7 space saver spares will fit. I don't know if that's really true. I remember my '75 Z took a full sized spare. What did they do with all that room? They put in a smaller tire and ended up with a much smaller usable hatch area. Is that something right out of the 70's, or what!?

On further reflection, the layout of my hatch is original, or at least it's the way it's pictured and described in my owner's manual. They speak very proudly of the "folding" spare tire (whose compartment is only as large as a large suitcase).