luseboy

You said you got a new master cylinder? Did you keep the old one? I know a lot of people have had problems with newer clutch master cylinders having too short of a master cylinder pushrod, causing the clutch to not get enough travel. If you kept your old master, see if you can put the old master cylinder pushrod into the new one. Otherwise you're gonna need to figure out a way to lengthen the master cylinder pushrod. Now I may be wrong here, as I think it may have been model specific somehow (240z or 280z) but worth looking into. I'm in the same boat as you right now but haven't really started chasing down my problem yet. Also did you bench bleed the master?

I mean I know it's gonna run high when it's cold and the oil is thick, but it had the needle on the gauge pinned. I may have a bad gauge or sending unit, but probably not as it's pretty consistent and is an autogage. Unless maybe I plumbed the sender in a bad spot that doesn't give an accurate reading. I am a little confused as to how it could be over 100psi of oil and not have anything leaking, but it may be because the motor was only running for a minute or a couple minutes at most. I do also need to get the thing full of coolant before I can drive it, I'm assuming I just want to wait for the thermostat to open with the radiator cap off and fill it and let bubbles come up to the surface? Or do I want to take the thermostat out and put as much coolant in as I can? I know this isn't really anything to do with the transmission lol but you guys are being helpful. I haven't confirmed if the pedal is set up right and all that. It's a new master, I think I re-used my old clevis/pushrod because I read the ones that come on the new masters are usually too short. But I never measured pedal travel or anything, so I need to do that. I will try lengthening the rod, and make sure it's working properly. I'm really hoping that my problem isn't with the clutch itself, but I believe I matched the throw out collar to the pressure plate, aligned the disk properly, and everything was torqued to spec. The fork is on the pivot right, with the little spring guy engaged and holding it in place, so I believe my problem is in adjustment of the slave and/or master. By reverse bleed do you just mean pushing fluid from the slave to the master? I work as a bicycle mechanic and bleed hydraulic disk brakes all the time, and different brakes seem to take better to bleeding one direction or the other so I have bled backwards in the past. I was actually thinking it would make more sense to bleed backwards anyways, as air moves up. I don't see why I couldn't put a big ass syringe on the bleed nipple and push some fluid to the master... shouldn't hurt anything anyways. Of course my problem could also be the adjustable slave rod I made, but I made it a good bit longer than the rod that came with the new slave so it should be long enough, we'll see. Luckily my daily driver is a big truck so I can tow it if I rent a trailer, but I could also just coast down the hill once I ensure my brakes are working properly. My worry is getting back up it, but I suppose I could just use a chain from the back of my truck to the front of the datsun and get it up the hill if necessary, there isn't much traffic on that street. The brakes bled out great and have been solid for the past two years, but I need to confirm that my booster rod was adjusted properly, hopefully the brakes don't lock up on me.

So I know this has been talked about a fair bit but I'm having trouble finding any definitive answers. I have an L28 (P79/F54 combo) with an AZC 4bbl manifold and an unknown header. I'm trying to figure out the "best" solution for PCV/Crank Case Evac for mostly street use. I have read about people using a crank case evac system pulling from the exhaust, but have heard this may pull too much vacuum and suck oil through the exhaust. I've heard that plumbing a PCV valve into the intake manifold is "bad" because then you're burning some oil/getting oil residue in the intake. I can't think it would be such a huge problem if so many cars come stock set up that way. Obviously it's not a huge deal because a lot of people seem to just put little filters over the PCV fittings on the block and valve cover, but I would like to have some vacuum in the crank case to help make sure all my seals are seating. So my question is, should I just plumb a PCV valve into the intake manifold and be done with it? Or would welding in a fitting to my exhaust for an evac system be a good option? With either of these options, is there any reason I shouldn't plumb a catch can in? And if I am going to pull vacuum through the crank case, should I pull from both the valve cover and the block? Or should I put a filter on the valve cover, and pull from the block? Sorry for the 20 questions, I'm just trying to figure out what I should do here as I'm finally getting my car onto it's feet after too long of a build, and this is one aspect I haven't really figured out yet. Thanks! -Austin

Ya lol it is quite high. I'm pretty sure the problem is the relief valve in the pump, apparently they tend to get stuck and then you just build pressure like crazy. Either that or some of the oil galleys are clogged up. The motor oil has been in for like 2 years, but is good synthetic oil. It still looks like new and smells like it too (I didn't taste it so not sure on that part). I'm actually thinking I should ditch the synthetic for some good ol' dino oil, which would be a good idea. Maybe the old oil is the cause for the high pressures, guess I will go get some dino oil before I run it again. I'll take a look at the trans fluid this weekend as well, I'll just pull off the filler cap and get a small sample out to take a look at. I don't want to dump that fluid if I don't have to, it was expensive stuff! The same stuff kept my hardbody trans working great for a year even though I pulled 1" long chunks of bearing out when I drained the fluid. I don't think there would be much water in there, it has been indoors the entire time I've had it, in a nice garage that has good door seals and what not. But then again it's not out of the question. If I remember correctly I need a gl4 for this trans right? Gl5 will damage the soft syncros, right? I've had to source Gl4 three times in the past couple years, and each time have not been able to find it anywhere locally. Most recently was with my dodge truck, which uses carbon fiber syncros and needs a very specific fluid... cost me $160. Actually just looked and I can get a quart of MT90 for $17, looks like this trans uses like 3 quarts or so, so I will be changing that out as that's not too expensive at all. But I'm gonna try and get the trans working first so that the existing stuff will help flush crap out when I drain it.

I can definitely attest to this. I bought my Z in high school and started working on it with little mechanical experience. I figured it would take me a year and a few grand to get it going with an L28. Here I am 4 and a half years later, with a whole lot more than I'm willing to admit into the car and I have never driven it because I'm still working on it. I went way overboard with suspension, brakes, wheels, body work, etc. and the project snowballed out of control. It's gonna be a really sweet car when it's driving but I also have to hold on to it forever because I couldn't even get back half of what I have into it, not that I mind as I love this car, but still. I would highly recommend that you don't throw anything away except for like interior parts and old hoses and obvious crap like that, but save all hardware! And keep track of where everything goes. Also definitely make sure your suspension, brakes, wheels, and tires are solid before doing fast stuff. I opted to just keep the L28 with a 4bbl on it and enjoy the corners instead of trying to go all that fast. It's too damn dangerous and breaks too much to be driving around fast on the street. You might also want to take a bit and really think about where you want to be in life in 5 years, I took some time off from going to college to work on my car and I really regret it, now I have to wait even longer to have a "real" job, so it might be wise to think about letting it sit if you can until you're out of college and making good money. That being said, much of this advice was given to me before I started my project... and well here I am neck deep in it.

That makes sense, well I'm sure you'll get it all figured out one way or another.

You know there are other options to raise the rear end back up, including longer insulators and/or upper spring perch. It's probably better to have the strut tubes the right length, but if you didn't want to re-do it there are other options.

SeattleJester, I think it was actually you who I was remembering. I know I had a post about the same thing basically a couple years back. I guess I will get get it into first gear and start it in gear and take it for a quick little drive. The problem is that I live halfway up a big steep hill, so I'm trying to figure out how I can test it on flat ground. Luckily my driveway is long enough to get a quick little test but I wouldn't be able to get it out of first gear. I just bled the clutch for the second time last weekend. The first time I put it all together I failed to install a copper washer at the slave cylinder and instead used pipe thread compound. Well low and behold it leaked all it's fluid out. Now I got it bled again after putting a copper washer on (and spraying myself in the eyes with DOT like an idiot lol). Although now that I think about it I didn't re bench bleed the master cylinder so maybe that's part of the current problem. Anyways even now that it's all bled out, the slave isn't moving the fork enough. I need to verify that I have the right amount of pedal travel first, then I'll look at the slave cylinder rod. I had made a custom adjustable rod just so I could make sure everything was set up right, as I got the slave with a non-adjustable one. Maybe that's not necessary? My thought is that maybe the rod is too short and that's why the fork isn't being moved enough. The pedal has no resistance until about an inch off the floor, and that's when the fork starts moving, but it's not enough. I guess I should also bench bleed the master again. Clutch is just a 240mm set up from ebay, some re-branded set up that might not last long. Pillar, that's some good advice. I haven't looked at the fluid yet, but will do that. I guess I'll just plan on replacing the transmission fluid and engine oil after I drive it a little bit, as the oil is definitely over 6 months old (maybe that's why my oil pressure is going over 100psi when I rev the motor, but I'm gonna check the relief valve in the oil pump first). I should be fine to get things up to temp for the first few times with the existing fluids though right? There's probably a lot of crap in the motor from taking it apart and there might be some in the trans too, so it's probably a good idea to replace it anyways. At any rate once I start driving it a bit I will have a much better idea of what's going on. I still got a good deal on the trans, even if it ends up being a spare.

NewZed this is totally what I'm thinking, I think once I start driving it a lot of things will come together, or at least I will get a better idea of what's going on with a lot of things. I've talked to a few people who have had transmission troubles after the car had sat for awhile, which went away with use. I reently got rid of a hardbody truck that had a blown up transmission I drove on for a year that worked fine once I put some redline in there. So I'm sure it will get better, or at least allow me to drive the car for a little while. Maybe I can find a cheap 4 speed or something and start gearing up for a 240sx trans swap. I guess at this point I'll focus on getting the clutch working so I can at least try to drive it. I think I need to make a new slave cylinder push rod to make that work, as it definitely isn't moving enough. I gotta start with pedal travel first then go from there, but I think my custom adjustable slave rod is the main problem there. How stiff are these clutch pedals supposed to be?

I guess I should have made it more clear that I'm saying it isn't going into gear with the engine off and the car sitting. The first time I put the trans in it wouldn't go into gear at all, so I took it back out, removed the rear case, and found that I had accidentally put it back together when it was inbetween gears. So I fixed that and put it back together and then it shifted fine (though required a whole lot of effort then too). Now the only way I could get it to shift gears was with someone spinning the rear end, which it would hit all gears of then, but made a grinding noise in 3rd and 5th I think. Unless I'm missing something, the clutch shouldn't have any effect on the trans shifting with the engine off, right? I'm thinking the small amount of rust that Pillar had mentioned is a likely culprit, but I also think that the shifter is too short as it's only sticking up above the console like an inch or two. As far as fifth gear going out, from what I could find online that is usually indicated by the shifter popping out of fifth while driving, so shouldn't effect what I'm having troubles with. I bought the trans for like $80 so if it is junk I'll either pull it apart (again) and actually rebuild it or just replace it with a better one and hold on to this one for spare parts (maybe use the bellhousing for a 240sx trans swap in the future). I just wanna be able to get it to work for awhile so I can drive the car (have never driven a Z but have had mine for 4 years lol). As far as the fluid goes I put that in years ago and can't remember exactly which one I put in but I know I did my research and it was redline gl4 mt90 I believe, it was what was reccomended to me on this site and is a soft metal safe version. I'm more concerned with the shifting itself rather than the grinding as if a bearing went south in there (they all seemed fine a couple years ago when I had the cases off), I'll just keep a look out for a different trans. I know I had talked to someone on here at one point that said their transmission wouldn't shift when it was sitting for awhile until they had someone spin their rear wheels for them, but I can't remember who it was or the context.

Well I haven't really done a thing to my car in about a year and a half, and just this past weekend finally got motivated to start working on it again, which is cool because it's close to being a drive-able car. Anyways a couple years back I bought a 280z 5 speed trans, which I quickly tore apart to clean up and make sure it wasn't junk. I then installed an msa short shift kit (which I cut down super short) and put it on the car. Well I actually had to take it off because I put the rear case on wrong and it was inbetween gears. Anyways it's been sitting for a couple years now and the shifter is extremely hard to move into gear. If someone spins the rear axle I can get it to hit the gears with a lot of force but otherwise I can't at all. I'm curious as to what could be causing the trans to not want to go into gear at all. My first thought is that I need to pull the shifter out and make it longer again, as I'm thinking maybe it's just so short that I don't have enough leverage, but when someone is spinning the rear axle it isn't too terribly hard to shift. My other thought is that maybe the fluid has settled down to the bottom of the bellhousing and the thing just needs to be driven some before the trans will start shifting well. But then of course the bad thoughts of "I fucked something up bad!" start coming in. Now I know it is at least able to engage reverse because with the engine running I can get it to grind trying to go into reverse (clutch hydraulics are not set up properly either but that's a whole different thing). I know no one can give me a definitive answer but I'm just looking for some experienced opinions as to what would be causing this. I'm probably gonna take the shifter off this coming weekend and lengthen it back to a reasonable height, so hopefully that will make a difference, but could there be something else going on here? I should also probably mention that when I did get it into gear and had someone spin the rear axle, there was an awful grinding noise that sounded like it was coming from the rear case. I'm thinking(hoping) maybe the trans will work a whole lot better once I start driving the car and get the trans fluid up to temp and what not, but maybe that's just because I don't want to take the damn thing apart for a third time haha. I know I probably didn't provide nearly enough info but hey that's how these things always start off. Thanks!

Ya definitely sounds like a bleed problem to me too. I would say replace the master if this keeps up. Also check and see if the reaction disk has fallen off. Pretty easy to check if you're pulling the master anyways, though you'll likely have to pull the booster too if it has come off. Check the condition of all your lines (hard lines and rubber lines) and make sure none of them are kinked, leaking, cracked, etc. as that could allow more air in the system. First place to start is by bench bleeding the master and then re-bleeding the whole system.

I knew you'd have an answer Leon. That's pretty cool that the 152's have a ported source. FWIW, if you really want to get into it you can actually adjust the vacuum advance settings (http://www.zhome.com/ZCMnL/tech/ignition.html). That said, it seems like a lot of trial and error, though I suppose these cars kind of work out that way anyways. I would confirm that your vacuum advance actually works before going much farther. It may not work, and hooking it up could just cause a vacuum leak if the diaphragm is broken/cracked. You can simply put a short length of vacuum tube on the hose nipple, and suck on the other end with the cap off. You should see the breaker plate move clockwise. Hold it there for a few seconds to make sure it holds pressure, and you should be fine if that checks out.

Hello, Search around as there are many great threads on here and classiczcars that cover this issue. In short, the basic problem with running a vacuum advance with triples is that they don't have a ported vacuum port which is what the distributor uses, but only have manifold vacuum which reacts to changes in engine speed and throttle input in a different manner than the ported vacuum does. You might still get ok results with manifold vacuum. The other issue is that some believe that the triples don't pull enough manifold vacuum (well rather, they don't allow much manifold vacuum buildup) to even move the vacuum advance enough for it to do anything. If I'm not mistaken, the 45 dcoe's only exasperate this problem compared to the 40's. Some people have toyed with the idea of making a vacuum canister that pulls manifold vacuum from all six runners of the manifold, but as far as I know, no one has been successful at getting that to work properly. Dcoe's are designed with racing in mind, and most racers don't mess with vacuum advance because once you get past 3k rpm it's already at full advance. Read up more on it, you may learn something knew. I never read too far into it because I'm running a 4bbl so I didn't have any real personal reason to find a solution. Tony D or Leon on here are going to be your best resource, so maybe shoot both of them a message. Tony is the engine guru around these parts, and Leon knows a thing or two (maybe three, not quite sure) about side draft carbs (oh and Z cars too!). Good luck!

I would also suspect that if the check valves were still in place they could also be causing problems. I have read conflicting things on whether or not they will work with disc brakes or not, but I know my wilwood master came with them installed on both the front and rear circuits. It's worth a shot to take them out if they're in there just to make sure. Don't remove the cones, they are what seal the brake line to the master, just the black plastic check valves.

Checking the reaction disk is super simple. Remove the master cylinder. Look down where the pushrod comes out and there's a metal retaining disk. Use a screwdriver/pokey tool/etc. to gently pry this piece of metal out, and pull the pushrod out. The reaction disk is a piece of rubber that should be sitting on the inside end of the pushrod. Glue it in place and put it back together.

I actually ended up being able to fix all of my rust. That said, I painted it like something out of mad max so I will be driving it to the ground anyways haha

That's great news! I've found with my project that everything that seems to kill the project or gets me really bummed about it ends up being figured out within a week or so. In fact I've found this pretty much to be true with life in general.

I'm sure aluminum floor pans is fine on a body on frame car but unibody means that all metal parts of the car make up the frame. Of course the floors aren't super structural compared to say the rocker panels or a pillars, but nonetheless it still has something to do with the general stiffness of the chassis. If you're gonna do it, do it at least halfway right. Sure aluminum won't rust, but it's also not very well connected to the steel of the rest of the car... I'm sure it's fine if you're not looking for performance but if you care about stiffness, it doesn't sound right to me. I'm no expert so maybe I'm missing something but that just doesn't sound like the best way to do it. Welders aren't that expensive, a decent mig or even flux core welder will be able to handle putting in new floor pans, and if you are doing an engine swap then you're going to need to be able to fab and weld brackets, mounts, etc.

In my case I had to replace the frame rails under the floors and about 1/3 of the floors themselves. Aside from one of the dog bones and a few other small areas like under the battery tray etc. I didn't have too much rust. I replaced my frame rails with some U channel steel I bought at home depot, and replaced them laying on my back with the shell on stands. If I were to do it again I would flip the car over somehow, probably with a rotisserie. It's up to what you want to do but in my opinion it's not too hard to replace them. The thing that kills these cars in my opinion is the rocker panels, as they are so important to the chassis. Quarter panels are tough too. Otherwise I think most of the rust issues are somewhat easy to work around. Whatever you do, please don't scrap the chassis as the more that happens the more rare these cars become.

That makes perfect sense, I didn't really consider that before. My car will be a street car so ground clearance is a bit important. I'll have to give it some more thought.

I do have a fiberglass kit I haven't used yet so maybe the modifications would be pretty minimal, minimal enough for me to figure out. While I understand that the works air dam is very "period correct" and looks the best, and is probably quite aero dynamic, something about how swoopy it is doesn't suit my fancy, I'm a much bigger fan of the straighter look of the bre spook. In fact the second set of pictures is almost exactly what I had in mind, and the third is pretty darn close. I think I will just get the bre spook and make it work somehow. Thanks for your reply!

I'm pretty sure it was actually the way in which they measured the horsepower that changed. I seem to remember reading something about that, but I'm no expert. The only thing I can think of outside of that is a different head and/or better use of smog equipment, but that's a pretty major change so I can't imagine what could have changed that. Interested to hear what the experts have to say.

So I've got a replica (read: cheap) 1 piece G nose for my car, and I've recently become fascinated with the idea of putting a BRE style air dam/spook/front spoiler onto it. I know the air dam offered by z car customs (http://www.zccjdm.com/catalog.php/azcarbum/dt46936/pd1993603/G_NOSE__240ZG__JDM_AIRDAM_) is essentially the same idea, and is better in terms of an aero dynamic perspective. I also know it's more period correct, yada yada. What I'm more after is the look, and I really think it would look good. What I'm mostly wondering is how hard it would be to make it work, meaning would the BRE air dam fit onto the bottom of the g nose without extensive modification, or would it be so much work to make it fit that it wouldn't be worth it? I guess the other thing to consider is ground clearance, meaning how low would that dam sit on the bottom of the g nose? Honestly I realize this is a pretty dumb post, and that my questions aren't that clear, but any insight as to how this might work out would be appreciated! Thanks! -Austin

Sounds like I'll go with the blaster ss then. Thanks very much for your input!