Zed Head

Looks like it, depending on how much hurry you're in. Some people think that the Tokico shocks have a harsh ride. They seem to be designed more for performance, not plushness. There are some pretty in-depth conversations on this forum, somewhere, about the options. Many are using KYB's with lowering springs and recommend them. Apparently, one potential problem is running lowered springs without the bump stops. It can damage the shock. Maybe that's the issue with KYB's. Note - I am repeating much of what John Coffey has said over numerous posts from the past, about tires, shocks, and bump stops. You could probably search those words and get a lot of good reading. Everything that you want to know is on this forum, from insulators to bump stops to Tokico to Eibach to progressive vs straight rate springs, all discussed within the last few years. It's a popular topic.

Silvermine seems to have a good reputation from what I've seen here and on other forums. They get good reviews for quality and response time. The kit you linked to is a lowering kit. You don't have to assume, you can measure and/or look. If it's lower than stock, it might already have Tokico springs or another brand. The shock mounts are also called "insulators" and quite often are in fine shape. Motorsport Auto sells them, for one. Harshness of the ride can be more affected by the shocks and tires than the springs. I would figure out what I had before buying anything.

"Popping" usually comes from a lean mix. Maybe your fuel pump is failing or your regulator has gone bad. Or your AFM plug fell off. Have you checked fuel pressure. A lot of money can be saved with the right measurements, and confirming what you think. Have you restarted the engine since the problem occurred to be sure that the tach is not jumping around? Have you tried removing the #2 and # injectors while the engine is running to confirm that they work? There's a lot of noise up there to be sure that you can hear them. You said that you can hear the AFM working. That is incredible, as in I can't really believe it. You may have heard air passing through it but the vane would only make a noise when the throttle blade is shut quickly, otherwise there is no noise to hear. The methodical and thorough approach is the best method on the EFI engines.

What do you mean by "flodding"? Running very rich? Search for threads about running rich, there are many. Could be the coolant temperature sensor, or a plugged fuel return line. Measure the fuel pressure with a gauge if you can, that will tell you if it's a fuel system problem.

78 doesn't use a crank sensor. If your damper slipped the timing mark would move, giving an erroneous reading, but the timing would not change.

Is the tachometer needle pretty steady and following engine RPM or is it jumping around? If it's jumping around and/or reading high it might be the ignition module.

Damage tends to lead to more damage. If you don't know how the rod got bent, it wouldn't be surprising to find more problems after spending money on the damaged short block. Could be a money pit. Getting another undamaged L24 and having it refurbished might be a better option in the mid- to long-run than having work done an an unknown short block with a bent rod.

Winter blend gas vaporizes easier, hot injectors, liquid vaporizing in injector tip before injection, lean mixture results. That's the best theory I've seen so far. Personally, I think that one or two injectors are in a hot spot, get overheated, and stop functioning properly. Fuel pressure leaking in the rail down doesn't matter anymore after the engine starts and the fuel pump re-pressurizes it. Certainly not after a few minutes (if you actually timed it you'd probably find that a few minutes is actually about 30 seconds at most). Many people have this problem and I've not seen a permanent fix from anyone, once they get it. Mine got better with a good set of Bosch injectors, and was non-existent all summer, but came back this winter (winter blend gasoline probably). You can spend a lot of time trying to fix it, and it will probably never go away completely. How long have you had the car and when did this start happening?

You'll probably break some studs and bolts and find stuff that needs repair in the head when you take the engine out to swap parts. Might be better off to buy a complete engine. How did you "spin" the bearing and how do you know? Everyone loves a good story...

Thanks, that clears it up for me. I was looking at it as attached at one of the long ends, not laid down. My perspective was off, if I had seen one out of the engine before I would have known the tab wasn't that long. Kind of surprised that Mallory didn't show more interest since it looks like a failure of their product. Maybe you were talking to the wrong guy.

Thanks for the reply. Maybe my brain is stuck, hopefully it will unstick later if so, but the picture of the shaft and the broken piece in your first post shows a counterclockwise twist. The distributor has two tabs that fit around the one center piece at the end of the oil pump drive shaft. That piece sticks up and it's twisted counterclockwise,looking down on it as it would be in the engine. The only way to do that is if the distributor shaft is twisting ahead of the oil pump shaft. But the oil pump shaft is the driver not the driven. If you held the distributor shaft in place, put the car in gear and rolled it backward you could get the same twist. Sorry if I'm not getting it. I enjoy looking at broken machines too.

I might have this backwards, and it doesn't help that the picture of the end of the dist. drive shaft is upside down but isn't the twist backwards for the scenario where the distributor stops and the pump keeps turning? Shaft turning counterclockwise, broken end pointed up. It looks more like the pump stopped and the distributor kept going. Maybe I'm looking at the wrong end of the shaft, or just thinking backward. I haven't actually had one out. Is it possible that the twist is old damage that finally fatigued and broke?

Don't forget metal fatigue as a possible cause for the tabs breaking. Fatigue doesn't take much force just many many cycles. Could be that the tabs broke off one a time. Since they are advance limiters, you might have had really high advance for a while before they jammed the shaft. BUT it is hard to see how the tabs could get in to a spot to jam the rotating shaft. Jamming the advance mechanism would just lock your timing advance in to one spot. Did you find the tabs actually wedged in somewhere? Seems like they would have done more damage if they were the cause and not an effect. The shaft locking up from galling or some other bearing/bushing type failure might have stopped things so suddenly that inertia broke the advance tabs. Just a possibility.

How about bending up a couple of U shaped brackets, with the bottom of the U flattened, drilling them for the through bolts, and bolting them to the original locations. That area is strong enough and you'll be able to use the original cross-member.

You could put a loop in the hose. Point the loop up so it won't catch on something. Make sure it doesn't rub on anything. Zip-ties work well for holding the loop where you want it. I did this for the outlet on my new pump when I installed it, for a similar reason. The hoses are in metric size. You're right, the outlet is smaller. I can't remember the outlet from the pump, but when you get up to the engine bay, it's 8 mm, which is very close to 5/16", which works great. Probably 12 mm on your inlet hose. I would guess that 3/8" (close to 10 mm) might work on the outlet of the pump.

I've had a clutch slave cylinder go bad within months of installing. I took the replacement apart before installing and found manufacturing grit inside, which I removed with a brake fluid rinse. So some aftermarket parts don't have the greatest QC on the cleaning side. Could explain the master cylinder going bad. It shouldn't leak, and there's no where for the fluid to go except backwards toward the booster. It could also leak down the face of the booster at the mounting surface. I also had a booster go bad after already having replaced the brake master cylinder. It was full of old brake fluid (that dripped on my paint when I was removing it), from the bad master that I had replaced. The car had sat for a few years. The fluid isn't kind to any plastic type materials and probably helped the booster disc fail. So I would say that yes, your master cylinder is bad, and yes that you should replace both. But the 1" master would give you shorter travel on the brake pedal but will require more effort, so you might want to consider that before deciding which master to use. If you get another aftermarket master cylinder take it apart and clean the bore, piston and seals, or flush it out well before installing. Edit - Forgot to say that the hissing sound and the motor dieing are sings of a bad booster. The hissing is intake manifold vacuum escaping and the motor dies because of it. Good point on matching part dimensions (below) before installing.

That was an exhaust manifold mounting stud. They break a lot. There are many Z's driving around right now with that stud broken. It shouldn't hurt to drive it a shop. Bummer, but it was probably already half-broken when you tried to tighten it. They crack and break from metal fatigue after a few tens of thousands of heat cycles.

That brings up one good point about the "bible" - it shows how to take the measurements from the connector at the ECU AND has the chart of temperature versus resistance on the same page. The FSM's are vague and you have to do some figuring and page-flipping to get to the same point. If Cethern has been using the 280Z Electronic Fuel Injection Book then he's already checked the connection when he took the coolant temperature sensor measurement at the ECU connector.

Other causes of running super rich are more common, but it is also a sign of a bad ECU. Some people have fixed theirs by re-flowing the solder connections from the connector to the board.

You got me. I made an assumption (that all fluoropolymers would be fine with brake fluid), and a bad suggestion. I should know better. Sounds like Eurodat has the best resource for figuring out what will work. Interesting thread.

You implied that the Drivetrain.com (Post #3) kit would be fine since your spirited driving days are over. It's cheap and almost complete. The missing bearing and nuts are available from courtesyparts.com (tamo3). I've bought bearings, seals and the countershaft lock nut from them within the last couple of years. You might try courtesyparts.com for the synchros also to be sure. Shows as available on their web site, and even cheaper than I thought. Put it in the cart and look at the red dot. - RING-BAULK :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com You can get part numbers from here, the 71B gear sets are essentially the same up to 83. Datsun 280Z Transmission Gears, Speedometer Pinion (5 Speed-FS5W71B) (From Aug.-'76)

I would be careful on material with the o-ring. Plain old plumbing o-rings might absorb brake fluid and swell (I tested an Ace Hardware o-ring to see if it could be used - it swelled). Viton would be fine if you can find them. I don't know what the typical material used is, and most manufacturers that I've seen don't list it. It's a problem.

The 75 files are 86 MB total. Have you taken any of the resistance measurements shown from page 45 on of the "bible"? The three tools that will help you the most are a multimeter, a timing light and a fuel pressure gauge. Without those, troubleshooting will be difficult.

The problems you described and the actions you took don't really follow, and the description is a little confusing. You said that the pump kept running when you turned the key off then the engine started running rich. But the engine can't run with the key off....? Plus you're on the "changing parts" path, instead of the "test and take measurements" path. Nobody can recommend a new part to change until you've taken a measurement. First, I would download the 1975 FSM and use it instead of the "bible". The "bible" is like using Cliff's Notes, when the original book is right there, and free. Read the Engine Fuel chapter. I would measure fuel pressure and record the resistance of the coolant temperature circuit. Those are two things that can easily cause a rich condition. As far as the pump goes, the wiring diagram is in the Engine Fuel chapter also.

I think that what's bothering some of us is why you aren't worried. Can't figure out why you're so confident, when you can't even get the gasket material off of the head. Maybe you're just okay with problems if they do come up, you'll just take it off and start over. Can't say that I haven't taken some chances like that myself but you seem a little over-sure that all will be well. Looks like an interesting adventure though. Good luck.