Zed Head

Just offering a counterpoint - there are numerous discussions around the internet also about the possibility that the high RPM weakness is either just a myth or is an early problem that was solved quickly. Many, many stories out there about no signs at all of high RPM problems. The cynic in me says that the aftermarket ignition module and coil companies have benefited greatly from this myth, and actually keep it alive with their unsubstantiated advertising claims. If you search, I think that you might find one decent article about the GM HEI system having a high RPM problem. I looked all over and there's very little real evidence of a problem, just repetition of something heard (no offense). I also found a reference somewhere quoting the guy who inadvertently started the initial rumor (might have been David Vizard) saying that his initial comments had been blown out of proportion and the GM HEI system was a good one. It was in a newer fuel injection tuning book in a book store so I may never see it again though. Edit - here's a link to a comment about Vizard and what might have been the book I was browsing. Not FI, but small-block chevys - http://cyberdave.org/HEICoilInfo.html If you read the whole link though, you end up with someone postulating again, with no evidence. It's like the perfect endless discussion topic. Lots of evidence for and lots against, and infinite combinations in between. On the coil - GM actually made an external coil for the early Novas and trucks (late 60's). You can buy it from Rock Auto or a parts store. This gives you the actual GM system, except for the triggering system in the distributor, which is based on the same principle. I have the standard (BWD, not high performance) HEI module and the GM coil on my engine and it works fine with no issues. Not even a sign. But my stock L28 is done pulling by about 5,500 RPM so I never go higher.

In the long run you'll be better off. I've seen numerous threads that started like yours but kept going with lots of money and time spent, then they still end up taking it home and doing it themselves.

Just realized that my comments about the shift rods sliding out of the adapter are for the front cover coming off. Eurodat's comments are more relevant I'm sure, he's spent more time inside these transmissions than I have.

The procedure is described in the FSM, Engine Mechanical chapter, about pages 18-20. Any 280Z FSM should work. I've found that Nissan changed the shape of the notch to a square groove for the ZX engines so you might look for that also. It's on the back of the timing chain sprocket, right above its hub or center, right in front of the camshaft retaining plate. The oblong groove is stamped or engraved in the plate. I attached a picture of the plate with the notch (it's right below the "4") and the illustration of what to look for. It's something that's easy to do and will confirm proper orientation of many different engine components, all in one shot.

I replaced my chattering Zoom Perfection (from NAPA) clutch with a Rhinopac. I can't say if the chattering of the Zoom clutch came from the clutch or the flywheel (I did not have it refinished before installing) but I can say that the Rhinopac is very smooth and has a lighter pedal (less pressure required). They're both OEM spec. so I think that the Rhinopac might be more precisely made to allow more leverage on the pressure plate. In short, I like Rhinopac over Zoom Perfection.

Did he say that you needed a new TPS or are you assuming? You might be misunderstanding what his remarks mean. There are only three positions for the throttle valve (aka position) switch - idle, wide open throttle and in-between. If he ran the check in the FSM and got the right values, then you don't need a TPS. Don't buy a new switch. It's not a variable sensor like on some modern engines. You might need a new mechanic. It sounds like he's guessing and not using the FSM or EFI Handbook, because 45 psi fuel pressure is normal for some modern engines but is way too high for these engines. 36.3 psi is the proper number and he should have known that. High fuel pressure would cause the engine to run rich and the exhaust to smell like gasoline. Old skilled mechanics are sometimes over-confident and will try to figure things out by looking and testing, instead of doing things the right way.

Look at Post #18 here - Suspension Bolts - Inventory - Brakes, Wheels, Suspension and Chassis - HybridZ Looks like there's a mistake in the FSM. You'll need to convert Newton-meters to foot-lbs. Newton Meter Conversion Chart (Torque Units Converter, Metric)

Is it a solid "no movement" or a squishy "barely moving"? If I recall right, the shift rods tend to bind a little in their holes in the center plate (adapter plate in the FSM), due to a little bit of mushrooming in certain areas. I'm just guessing, so be careful. I think it just takes a lot of awkward tapping to get everything out. Could also be that you're not in neutral. The balls on the shift rod move in to spaces on the adapter (or vice versa) if not in neutral and the rod can't come out. Just guessing again. It's probably a shift rod that's sticking though.

It's not perfect, due to chain stretch, but you can get a pretty good estimate of how bad the mark might be off, or find the right one, by pulling the valve cover, turning the engine over until the #1 cylinder cam lobes are pointed up, then turning the engine a little more (in it's normal rotation - to keep the chain tight) and aligning the notch on the timing chain sprocket with the groove in the cam plate (as described in the Engine Mechanical chapter). Could be that the wrong pulley mark is being used. If the right one is on the damper pulley and nothing is damaged, and the cam shaft is installed properly, this would find it. Another possibility is that the engine has a 240Z damper that is marked for the opposite side of the engine, and someone cobbled together a ZX style pointer because they lost the other one when they installed the 280Z engine. If so, the procedure above will end up with a damper pulley mark under the distributor somewhere. An early 240Z pointer might solve the problem. I don't know when they switched, and I can't find a reference but I've read that the early Z's had the mark on the driver's side.

Your clutch is probably either worn out or has a problem at the friction surfaces. I had one that did what you described when it got warm. The hotter the weather and the longer I drove it the worse it got. It could get really bad, shaking the whole car. It was okay when cold. Changed the clutch, flywheel (I had a spare) and pressure plate and I was back to smooth take-off.

I would think something from the driveshaft back to the rear wheels. Pieces that get extra load under acceleration and can twist out of shape if something is worn or loose. OR, it could be a sticky clutch. I had one of those. Does it happen while releasing the clutch pedal to get going, or after the clutch is fully engaged (pedal all the way up for those iffy on "engaged") and you're on the throttle?

Here's an interesting paragraph from Humble's Restore book. I wonder if the forum's parts CD has an illustration of the referenced upside-down installation.

Looks like Black is ground (Earth). Hard to tell what it's grounding though from the drawings. Sometimes Nissan runs a dedicated ground wire to the cover. Check the cover for solder. Didn't realize also that you were dealing with past problems and broken wires, your first post made it sound like this was a fresh problem. That kind of changes the situation. The internally regulated alternator might be the way to go, although it could take some problem solving to fix other things that might be affected by the external VR. You'll go from 50 amps to 60 with the ZX alt which might be worth doing anyway. But I think that might be possible just by getting a 1976 externally regulated alternator. Many paths possible.

You didn't say anything about precision. I'm not sure what that means here, since it just needs to be wiithin a certain fairly wide range of charging voltage. Seemed like you were implying that you might have problems, and really, the only problem you have with a VR is when it fails. I was referring to VR failures. The solid state VR might last longer under normal conditions, but the mechanical would handle the abnormal conditions better, I think.

Actually, the solid state VR's tend to have more problems with stray voltage spikes from things like ignition systems, or too much current flow from things like charging dead batteries. The old mechanical systems should be fairly robust. You should call MSA on that alternator and see if you're paying the extra $20 for real higher output or just the turbo name. Ask if they have output specs. for each unit.

The drone is typically solved with a second muffler midway down the system. Stock Z's came with anti-resonation mufflers in that spot. You might try a simple modification there before buying a whole new system, at least to know what you need first. Many people use a glass pack instead of the stock anti-resonation muffler and say it does the job fine. The stock piece is a little bit restrictive.

I've had one bad ECU and its death characteristics were to die instantly, come back to life for about 1/2 mile, die again, start again, die again, flood the engine with fuel, then never start again. I replaced the two injector transistors and got it to work again (just for fun, not because I knew what I was doing) but have only taken it for a test drive since then. Something to consider is that the transistors used for the injectors are very similar to those used in the ignition module, and ignition modules do weird things before they crap out for good.

madkaw is right, that's a 280ZX pointer. I have one too but had forgotten what it looked like. But the damper doesn't look like a 280ZX or a 280Z. Your engine and head numbers are for a 75 - early 77 280Z L28. So you do have a bigger engine than came in the 240Z. If it's stock, it would have dished pistons and ~8.3 compression ratio. Somebody could have swapped pointers from a ZX, and a damper from some other engine. Who knows. Welcome to the world of old cars.

It's really hard to emphasize!!!@@@## how much better and smarter you'll feel!!! if you run the resistance test for the coolant temp. circuit from the ECU connector!!! Once you know that the ECU sees what it should see!@#$#% then you can stop guessing and buying parts @#%%$ Seriously, just unplug the ECU connector, measure resistance to ground at the right pin (13? I believe, it's in the Engine Fuel chapter) and compare the number you get to the chart in the FSM (it's in the Handbook too I think). You can do many of the other component checks also, like the injector circuit, Pin 1 to coil, etc. It's much easier than it seems and really, it's where everyone should start.

I'm not so sure that's an L28. Can't tell by the one picture in the thread. Maybe madkaw's assuming, because it doesn't look like an L24. That damper and timing marker might not be common to either engine. The L24's have a single pointer, with degree marks on the damper, and the L28's have a single mark on the damper with degree marks on the marker. But there are only six marks, in increments of five. -5, 0, 5, 10, 15, 20. You have something unusual.

So this is a project, that had not run for a while. Lots of unknowns then. Many of the auto parts stores can test alternators, batteries and VR's, all on the same machine. Even the external VR's. Worth a shot. Best to know what's wrong before you do a conversion, otherwise you can do excellent, careful, conversion work and end up with the same problem when it's done.

I don't think that these are signs that your alternator or VR is shot. Seems more like you mis-placed a wire when you put things back together. Do some of the testing described in the Electrical chapter. You might be on a wild goose chase. On the MSA plug, I think that it might work for an early 260. You didn't say what you have. Compare your wiring to a 240 and see.

Looks like you're using the EFI Handbook for your testing. The Handbook is a generic document for the 280Z's and/or the 280ZX's, depending on which version you have (1975 or 1980). You should start working from the FSM, with its information and diagrams that are specific to 1976. Read the first few pages of the Engine Fuel chapter and the Emissions chapter. They describe all of the weird little devices that you're working with. Then do your circuit testing from the ECU connector. Then you'll know if the wires and connections are adding resistance or shorted. Many people remove the CSV system entirely, the switch, the valve and the fuel lines. Cars are designed for a very wide range of environments, and I think that the CSV is for people in the mountains or the midwest. If you're worried about it being stuck open causing richness, just block the fuel line for a test. Index of /FSM

Check the Steering chapter, or the carpartsmanual link. There are pictures. Index of /FSM/240z/1972 Datsun 240Z/260Z/280Z Steering Gear (Rack & Pinion Type)

The coolant sensor is one of the major control components in the EFI system. If it's not connected the ECU "assumes" that the engine is stone cold and that it's in Antarctica. It has to be connected and working correctly to even have a shot at the engine running right.