Zed Head

The R200, with 3.54 ratio, is the only differential used for the 1975 to 1978 280Z's. It's shown in the Service Manual. They're hard to rebuild right, from what I've read. They seem to be a noisy design in general, but much of the noise can be isolated with the right bushings, and a little sound deadening material in the back of the car. You might do a little more reading, there are more frustration stories than success, from what I've seen. Are you sure it's the bearings that are making the noise, and have you checked to see if the diff was full of fluid? After 36 years much of it will have escaped through the breather.

I had that leak and had to lay a bead of silicone around the complete perimeter of the glass/seal interface to keep the water out (I really don't want to replace the seal). The water can get in anywhere along the outside edge, gravity takes it down the gap inside the seal between the glass and rubber, it travels inside the seal to the low point and comes out on the inside corner. I tried sealing just the bottom corner, then the whole bottom edge, then the bottom and the sides but apparently there was enough water rolling over the top edge and under the seal through capillary forces to get in and fill the gap inside the seal. For anyone wondering, the way to see if you have this leak is to take a long wide left or right turn after some rain or a washing and watch for the drops of water magically appearing at the inside corner of the window and seal. The water doesn't leave much of trail when it beads up and rolls off the rubber so it's hard to find otherwise.

There's a tiny screw holding the odometer cable in place that has to be loosened. It might be possible with tiny hands but I think that you'll need to remove the tach to get to it. Stick your hand in the tach hole toget to the backof the speedometer. You might find that you can wiggle the cable end and retighten the screw and the odometer starts working again. The tip of the tiny screw fits in to a tiny hole on the end of the cable, locking it down so that it can't slip. You might also be able to slip a stiff piece of paper or plastic or metal between the speedometer edge and the lip of the dash cap to get the tach and/or speedoout. Make a little ramp to slide it past the dash cap edge. A little Armorall to make things slipperier would help too.

I think that the factory put a lot more effort in to tuning the timing than the distributor rebuild companies do. If you look, you'll find the same part number for a whole range of years from the rebuilds, but no vacuum advance data. They are either using a generic, probably mild and safe timing advance, vacuum canister, or each canister has a random advance curve. I think the canister is new though, so it's probably just a mild 10-12 degrees total at high vacuum, to avoid any pinging at all. I can understand the urge for a backup plan. That's how I ended up with the GM HEI module. I installed it just to make sure it would work if my factory module died again, the left it on and kept the factory module as the backup. I'll probably never use it again. CO made a good point about the dual pickup ignition. If you go away from the factory ignition setup you will lose that. On the manual cars, like my 76, it's main purpose seemed to be to keep the idle speed up while the engine got warm. It might have a different purpose on the 74 auto cars. Should be described in the FSM though. I deleted the second pickup on mine and just live with a low idle for a couple of minutes between the AAR closing and the engine reaching full temperature.

Every suggestion in this thread is worth checking, even if the problem goes away. Get a meter and a pen and paper and go through the tests in the Engine Fuel chapter. Almost guaranteed that you will find somethings that can be improved and your engine will run better when you're done. If you read through the chapter first you can put a table together that will show what the measurements at the pins at the ECU connector should be. For some reason Nissan broke the testing up in to testing continuity at the ECU first, then real numbers at the component itself. Easier just to measure real numbers at the ECU. For example, measure resistance at the ECU pins for the coolant temp. sensor, instead of just continuity. Don't skip the fuel pressure check either, that would be another cause of lean running. You might have a weak pump. And a sign of a plugged exhaust is a lack of pulsing at the tail pipe.

Could also be the TPS. Read the Engine Fuel chapter, it describes how the ECU delivers "full enrichment" above a certain throttle opening based on the signal from the TPS. Shows how to test it also. No throttle signal to the ECU, no enrichment, lean mixture, popping and surging. Maybe.

If the Z stuff is the same, this option might work. It's light-weight so shipping shouldn't be too bad. Bottom of the page. They take phone calls and credit card numbers. Seattle, WA. http://www.datsunstore.com/index.php/page/2/sort/2a/cName/7578-280-z3-weatherstripping-3

If you know the year of the distributor, you can find the advance curves, and details about automatic versus manual in the Electrical chapter of the FSM. Along with diagrams and drawings of how things work and go together. I don't think that the ZX vacuum canister will fit on the Z distributor. It's different. www.xenons30.com/reference www.xenons130.com/reference

Thanks for the kudos clouds. Good that you found a mechanic that can trace a circuit and figure things out. Plus take things apart and fix them. A rare find, from what I've read on these forums.

Note the comment about "details may differ" - http://atlanticz.ca/zclub/techtips/distributor/index.html If you have the 260Z electronic ignition with VR distributor, you could use the GM HEI module in place of the stock module. Cheaper, and just as effective. Check the advance mechanism on both distributors. If either doesn't move, take some time to break the rust on the ball bearings loose before forcing it. You might be able to get it moving again without breaking the plastic bearing cage.

Actually, I think it will allow you to send more shock load to the differential. Less mass to damp engine engagement through the clutch. Probably won't matter unless you're drag-racing, although I could see a higher modulus material transmitting higher frequency noise. Might be noisier, but I haven't seen any accounts. I have read stories about the aluminum shafts not liking harsh treatment through the clutch. Apparently the u-joint yokes can get damaged. You can buy a slip yoke and have a new steel shaft made for ~$250 bucks easy I would guess. I have found a local guy, up the Gorge (Portland talk...) who would shorten one for $90, which turned out to be essentially building it over again after cutting it. A good shop could probably source the yoke too. Just take your old one in and say "make me a copy of this, please". You might be spending more money than necessary for a relatively simple part.

The alternative to the full harness would be one of FricFrac's repair kits. http://forums.hybridz.org/index.php/topic/104419-s30-and-s130-wiring-harness-repair-kits-you-need-this-if-you-have-an-l28e-or-l28et/#entry1020367 You said that you were gauging interest so it seems like a good thing to know before you get too far in to it. He is a member here and posts occasionally.

I would look in the service manual and compare the vacuum and centrifugal timing curves first. The later year 280ZX distributors had some pretty aggressive vacuum advance curves, for emissions and fuel mileage purposes. The wiring diagrams are in the manuals also and will show you the differences between the two types.

The purpose of the FPR is to maintain a constant pressure differential between the fuel in the injector and the environment at the tip. So that the ECU can control fuel supply accurately with injector open time. So if pressure goes down in the manifold (vacuum reading goes up) then fuel pressure in the rail will go down also. If pressure goes up n the manifold (boost) then pressure goes up in the fuel rail. The FPR in your link in Post #3 should work fine as long as you want to go richer than stock in your tuning, which it looks like you do. Actually, it looks about like what FastWoman was describing, a stock regulator that's been modified to allow spring pressure adjustment. 45 psi is actually a pretty big increase over stock and should supply about 12% more fuel than 36 psi. The unanswered question about the Summit FPR is whether or not it will leak down like the Aeromotive and your EBay FPR.

They just had a thing on the local TV news about that same EBay ad - using "sex" to sell cars, is it right? The owner, Ridley himself, said everybody does it, and gave the Carls's Junior ad for BBQ as an example. Weird.

Fastwoman was talking about inches of vacuum here, in Post #47, but in the previous post, #46, it looks like you're reporting RPM. Have you measured intake vacuum yet?

The proxy thing sounds interesting as a clue, but I wonder if it wasn't just coincidence. I'm still locked out as of 6:15. It seems to go off and on. There must be a trigger somewhere.

Thanks John, I sent him a couple of screenshots from Firefox and Chrome. Still locked out as of now - 1:28

12:31 and I'm blocked again, from all Hybridz pages. I don't think individual "shout-outs" are going to help. A description of your "proxy work around" to view the site might help SuperDan figure out what's going on though. Why don't describe what it is?

Yes, FW, there seem to be several ways to go wrong in front of n.n. Eurodat mentioned removing the injectors (maybe he meant something else?) in Post 51 in order to adjust valve lash. And I think that the nylon rope trick is for holding the valves up for changing valve seals. Both way more work than necessary. In the Engine Tuneup chapter of the FSM, the valve lash adjustment procedure is pretty well-written. It is the first tuneup procedure described. You don't need the fancy tools though. There are several internet procedures out there for adjusting them while hot, but just do it cold first, then check hot if you're worried. The hardest part will be getting the lock nut loose without busting up your knuckles or bending your spray bar. Use a heavy mallet to tap on a wrench instead of trying to muscle it loose.

It's been over the last couple of days. I just replied over there to SuperDan's (the admin) query about whether the problem still existed, that I had had the problem again this morning, then immediately got blocked again. Still blocked. Maybe it's a firewall or old OS problem. I'm using Windows XP. Tried Chrome and Firefox and they both block. Edit - and now I'm back in...

It's not you. They're having issues. The "banning" is sporadic and just started. I'm sure it's being worked on, somebody even started a thread about it on the site.

If you connect the light, start the engine, and rev it up, the pointer will move away from the zero mark, crossing the other marks as it moves. I'm not familiar with the 240Z marks, so can't say if the marks start at zero though. On the 280Z, there is a negative five degree mark.

You said that it runs great. Are you just trying to fix the gassy smell from the exhaust now? Where is the timing set, and what is your idle speed when you're measuring intake vacuum. Also, measuring the resistance at Pin 13 of the ECU connector is the best way to see if your coolant temperature circuit is clean. Resistance on this circuit will make things richer. Compare the resistance measured to the temperature vs resistance chart in the FSM, Engine Fuel chapter. Make sure your valves are adjusted, check the coolant temp sensor circuit, verify fuel pressure including the function of the vacuum hose attached to the regulator (~30 psi fuel pressure at idle. 36 w/o the hose connected), drive it around for a tank or two to loosen things up, then decide if you want to mess with the AFM. You need to get all of the very basic stuff right first.

I just looked through the FatCat site, thanks for suggesting it. The Technical Data link under Bump Stop Kits is worth a click. My post would have been shorter if I had looked at it first. $100 to do all four corners doesn't seem too bad. I tried to get some Jinba Ittai but the link was broken. Bummer.