Zed Head

Heat has a much bigger effect on hole size than many people imagine. Heat up the control arm ends and the old sleeves will probably press out (I pressed out both of the inner sleeves on my front control arms with a shop vise and a MAPP gas torch), heat up the strut housing and the bearings will probably press in easily. A propane or MAPP torch will do the job with about 5 minutes of applied flame. No serious chance of damaging the metal, it won't even get a glow going. Apply some preload with the press, start heating and things will move when they're ready. The inverse of using the torch to get things out is preheating a press fit ring or collar, like the ring gear on a flywheel, before installing. Heating it, then letting it cool, makes a super tight fit. So if you have a super tight fit, heating will make it looser.

If everything is clean and nothing is rubbing, and the problem goes away when air flow stops, then it seems like the only think left is a pressure imbalance between the two sides of the blade, the trailing edge and the leading edge. I had a similar problem and started thinking about this but then found that the problem was varnish/gunk/residue in the throttle body. I cleaned up with liberal amounts of carb cleaner and some Scothbrite so don't really know if there was crud in the ported vacuum holes or not. Here's one off-beat thought though - how about the AC idle-up mechanism, the thing with the vacuum pot and the hook that pulls the linkage when you turn the compressor on? Maybe it's activated through a shorted or leaky solenoid. You might not notice it if you're staring at the throttle body.

ksechler is probably looking at the FSM procedure, which describes leaving the transverse link (control arm) installed and removing the spindle pin to remove the upright and change the shock insert. If you remove the control arm, by disconnecting the inner mounts, along with the upright, you do not need to remove the spindle pin to get it done.

You can also pick and choose the bearings you want to replace from CourtesyParts. I would use carpartsmanual to compare the A and B style parts, then Courtesy or drivetrain.com to get what you want. Note that drivetrain.com has the A, B and C designations wrong, by model and year of car, on their web site, as EuroDat notes for the C kit. I've sent them messages and copies of the FSM, and received replies back, but they don't seem to care or couldn't comprehend. Here's a trail to the countershaft bearing, for example - http://www.carpartsmanual.com/datsunS30/DatsunZIndex/PowerTrain/TransmissionGears/4Speed/ToAug71/tabid/1710/Default.aspx http://www.courtesyparts.com/bearing-p-341410.html

This won't help the resolution of the discussion, but it has the word "engineer" in it - “An optimist will tell you the glass is half-full; the pessimist, half-empty; and the engineer will tell you the glass is twice the size it needs to be.”

Imported maybe? I recall a post from Hybridz, ozconnection (from Australia) had an N42 head with no notches. Post #59 - http://forums.hybridz.org/topic/62691-l6-heads-pics-and-descriptions/page-3

It's easy to remove the inner control arm mounts and take the whole two sides of the triangle off, the strut and the arm, as an assembly. You can dink around with trying not to break the brake line open but that's also much easier than you would think. I've wasted lots of time trying not to remove the brake line and to keep the arm bolted up but in the end I realized I had just wasted more time and taken more chances on damaging something, like the fender well lip or the brake hose. If you're planning to do the brakes, including flushing with new fluid and bleeding, just take the whole thing out, but remember to break the main strut/shock nut loose first. If you don't have a spring compressor, try Harbor Freight for a cheap one, you'll need one. You might find that the inner bushings are in good shape and decide not to replace them. The KYB shocks should work great, especially if you're not lowering.

The N-42 heads have the threaded holes for mounting carburetors AND the notch in the intake for the injector tip. The injectors are mounted in the intake manifold and stick through in to the top of the head's intake port. So you can use EFI or carbs on the N-42 for sure, maybe on the N-47 also, not sure there. Apparently, in other non-domestic markets carburetors were used for quite a while after EFI was introduced in the states. I think that the big driver for EFI was the emissions regulations in the US market.

It is fun to turn that knob and get an immediate effect. Too bad you're short a few fingers for a while, might make it difficult. I wish we had more tuning tools that were so simple.

Car and year would help. I have a 76 and all I see is a body-colored panel that flows with the body lines, with nothing on it. I think that there's a notch in it for the exhaust pipe. Your description of what you're thinking about is not very good.

No problem. Get some bullet connectors and about 8 ft of wire also and you can just unplug the wires to the coolant temp sensor (bullet type) then plug in the potentiometer wires, with no wire cutting, and mount the pot inside the cabin. Tune while driving. If it doesn't work, just unplug it and go back to where your were, no damage. Good luck.

I don't think that you ever really said what you're trying to do, but it looks like you're trying to make things richer. I agree with FastWoman, that adjusting the spring in the AFM will affect low RPM and high RPM (low and high air flow) differently so is not an ideal way to do things. Adding a resistor will make things richer at all air flow levels. I used a 5k-ohm audio taper potentiometer (volume knob) from Radio Shack, part #271-1720 to adjust the resistance. I installed it originally just to be able to add lots of fuel to try and fix the hot start problem, but then found it was very useful when I ended up with a lean AFM, that had a lean flat spot at low RPM. Basically right after taking off from a dead stop, the engine ran through a flat spot then jumped ahead when it hit the good spot. The pot allowed me to tune out the flat spot, but it also turned out the whole curve was lean so it ended up as a really nice tuning tool, for my specific lean-running AFM. For the record, previously I had had a rich-running AFM on the engine but had no way to adjust besides an adjustable FPR. Which leaked down as described. Anyway, get the audio-taper model, the linear model is much harder to control. And 5k is really too much range, I only use the first 1/4 turn of the knob, so a smaller range would probably work even better.

You can only make the mixture richer by adding an inline resistor. But, as grantf suggested, it looks like you still have basic problems to get right before any tweaking should be considered. Your fuel pressure, for instance, should not be jumping to 40 psi. Maybe you're just seeing the needle bounce. You can test it by removing the vacuum line from the FPR while the engine is running, or removing the wire from the solenoid and turning the key to Start. It should be about 36 - 38 psi. If you can't get the engine to die or almost die by turning the idle screw in then you have a vacuum leak somewhere. If you have a vacuum leak and it's still running rich, then you have a fuel enrichment problem, either through too high fuel pressure or something like the TPS or coolant temperature sensor circuit. Lots of basics to get right before tweaking the AFM or installing a resistor. There's really no way around it. I've not read any posts where someone reported that they tested and measured the circuits described in the Engine Fuel chapter, and wished that they hadn't because t was a big waste of time. It's worth doing. The fuel pressure dropping to zero is more of an irritation than a problem to worry about. It's pretty common and there are fixes for it, but that's not your main problem. Get a meter and start probing. Good luck.

It is a magnetic pickup coil, probably off of a 260Z or a 280Z. Somewhere on this forum there is a spreadsheet of all of the Z(X) distributors from points-style to ZX style, with part numbers for each. The part numbers are in the FSMs also, if you wanted to take guess and open up the Electrical chapter. Before you get too carried away, take the breaker plate off and see if the ball bearings are still there and free to move.

I'm sure that you realize this already, but your knowledge of automobiles is not much. You have a jury-rigged fuel pump, a jury-rigged "sensor" to stop the high idle speed and smoke coming from a part that should only get power when the key is turned to Start. You're changing parts and getting ready to change more but don't have a good reason why. It looks like you're testing things by looking and touching, I don't see any meter readings. I don't see any signs that you're really making any progress, I wouldn't be surprised if your next post said "problem solved , the car burned to the ground". You have a serious dilemma, I would spend your free time trying to find a good mechanic or getting a meter and learning how to use it. Sorry, but you really are in danger of destroying the car.

Firstly, I would not use that mechanic again. Unless you didn't understand what he was saying, he does not seem to have even the basic skills required to work on EFI systems at all. Power in the wires but can't make the pump run, leaky fuel lines stopping fuel from reaching its destination in a 36 psi EFI system with a return line, air in the lines stopping flow, waiting for gravity - all bad. Edited my previous comments and gave the guy the benefit of the doubt. He might be a great mechanic for carb'ed cars. Based on the last statements, that it will run for a few seconds then die, even though the pump is running, it sounds like your injectors might not be firing and the engine is running off of the gas from the cold start valve. Or the fuel pump inlet could be clogged, but it would probably run for a more than a few seconds if so (note that "few" generally means about three). Just guesses. Looking back in the thread, it seems like it hasn't run since the welding was done. Maybe something got fried in the ECU. Keep looking for someone that knows how to work on old EFI systems, not someone excited to work on something they don't understand. Download the FSM, print out the pages of the Engine Fuel chapter and let the real mechanic do some component testing. All of the proper tests are described in the Engine Fuel chapter.

The following should help, in no particular order - Describe the car - year, model, and any modifications. Download the service manual and read the Engine Fuel and Electrical chapters - www.xenons30.com/reference or www.xenons130.com/reference Use capital letter's periods, and commas to make your posts easy and pleasant to read. It shows that you care and makes people more likely to get involved with your problem, and that there's hope that their contributions won't be wasted.

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