txvepr

I have not been able to I.D. this plug in my service manual. , on the driver side of the block at the back of the engine. 22mm bolt head. Is this a coolant drain plug? instead of a freeze plug? Also notice that inside it seems to be completely filled with junk.. ;-( Thanks.

So, I am guessing that a new clean engine with clean valves would have almost sealed cylinders? And as time goes on, carbon, etc.. buildup will cause those valves to not seal completely plus any wear on piston rings would also have effect also.

Does anyone have Leak Down specs for a newly rebuilt L28 engine versus a well used one? I am starting a rebuild on an old engine and wanted to know how what I currently have would compare to an engine that will have new rings, valves, cylinder honed, etc.... The rebuild engine is not really showing signs of being worn out, and the previous owner indicated that it ran fairly well. It was pulled before I got it so I haven't seen it run. Here are the Leak Down Test results for my project engine for comparison: These are all in the green band on the gauge. 1: 15% 2: 27% 3: 30% 4: 15% 5: 17% 6: 15%

Spent some hours under neath the Z, putting in a 5 speed. A funtime had by all!

Wow. glad the sites back . I am grateful for everyone's information. It turns out it was the Throwout Bearing , I had used the one that was on the 5 speed rather than the one I had on my 4 speed, which probably matches up to my current clutch. We pulled it again and installed the different one. When I compared the two, it was very hard to tell the difference, measured with calipers and the big difference was the thickness of the bearing sides, and a very little on the throat. Not as apparent as those pics would suggest. Weird the part number was the same on the bearing part. I saw those pics you posted. Once it was back on and buttoned up, the transmission pulls very well! and no slipping. Now to get used to shifting to 5th gear way out there. I looked all over that 5 speed housing for any identifying numbers and could not find any to determine if mine is a early model or later, other than what the seller told me. Is there a way to tell just from looking on the outside? Anyway, I appreciate it, and now feel like I'm at least an expert on how to remove and replace a transmission!! wooot!

So I just installed a 5 speed transmission in my 78 280Z. Used to have a 4 speed. Before installation, nothing was wrong with the clutch, and I did not think I needed to replace it at the time. It was strong and never slipped. I did not remove the clutch and it seemed to be in good condition as far as I could tell on the flywheel. While test driving after the install, I notice that it seems like the clutch slips a bit at 3 & 4 gear shifts. The question would be is this a sure clutch going bad ? or could it be something along the lines of my clutch pedal/slave cylinder needs adjustment? I find it odd that the clutch would go bad at this exact time, but I do not have experience in this area of installation. Any ideas? Thanks.

Wanted to give an update on this to anybody who cares. Symptom was my fuel tank was getting pressurized after running. If I opened the cap, I would have a huge rush of air coming out of the tank. I could also hear the fuel pump start to get louder or sound like it was working harder. I replaced the "fuel unit assembly part 17331-N4200" ,which the service manual calls a fuel check valve btw. I found a NOS one on ebay. and This has solved that problem. No more pressurized fuel tank, fuel pump sounds happier now. I don't know what else will return to normal at this point, but it can't hurt!

So my Fuel Check Valve is not checking anymore. Opening the gas cap releases a great amount of pressure, and I can hear the fuel pump getting pretty loud too after a drive. The manual shows the 'Fuel Check Valve' inline from the vapor canister back to the fuel tank, and after checking it it seems to not be working as desired. Have replaced gas cap recently. 'Air does NOT flow smoothly'from the engine side when I tested it. I have not found one available or listed at any auto store, and Ebay returns the Brake booster valves on a search. Does anyone know of a substitute part # that will work? They don't look too complicated and surely other brands used something similar? Please let me know, I can't have my fuel tank explode on me on the way to work! Thanks.

Any new progress to report on this project? It sounded like it was going along well for a while.

The 3 most annoying hoses in your Z. I know there are more complete posts out there on heater replacement. I am posting this to pass on a modern alternative to the braided hoses for the heater. Unless you are going to Consourse, this is an available replacement you can get today at Autozone. That's usually when I need them. Now! No parts store has anything listed for our old cars on this, you have to just eyeball them. Here are the stock numbers: Dayco A70785 Dayco B87653 Dayco B70873 This is on a 78 280Z, yours may be similar. They are 5/8 inch. Original Hose shot: There is a third hose you cannot see in this pic. Replacement Hoses From AZ. You will need to trim a little bit of excess from the new ones. I suggest you match them at the bends for best results. I also went with new hose clamps, I hate those original wire clamps. When you do this, take your time. I would highly recommend you use a trashbag to line the floorboard to catch the coolant that drains out of the lines. Use a water bottle too. Also open the radiator cap and disconnect the heater hose in the engine compartment. Remove the trim panel, Remove the glove box, remove the entire blower assembly box. You dont have to take the fan off separately. Its 3 bolts and 2 electrical plugs and 1 vacuum line. Remove the defrost vent horn. Now you can get to work. Enjoy your leak free heat!

This is your first red flag. You will have to be your own mechanic if you plan on owning and DD a 280Z. Even if you were able to find a competent mechanic, you would not be able to afford his services for very long. 36 yr old cars need a lot of basic repair and replacement of parts that you would never think of in newer ones. I DD a 78 280Z up here in Dallas. It has factory R12 air that will hurt you on high. It can handle the Texas Summer very well and I depend on it every day. I know one day it will finally die, but for now I enjoy it. I still love my Z!

Are you sure its gas and not exhaust? As Z drivers we get to become aficionados on the subtle differences! Another thing I have found it the rear wheel wells will have seams that have opened up. Put a drop light under neath in the well, and then open the back and remove the interior panels and look for light. I had to reseal them with RTV or silicone and it helped alot.

Solution: Alright, I wanted to report back on the solution so others will not forget to check this really simple, but important part of their fuel system. Symptom: Attempt to restart car after driving for any length of time, car would fire up and immediately die. Then any amount of cranking it would not startup. Appears to be fuel starvation. Or in hotter temps you would think Vapor Lock. Quick and dirty test: Open Gas cap and try to start. Success each time. Replacing the gas cap has solved this problem. Testing the old cap(manual EC-25) with a new one confirmed that the tiny valve in the cap was not relieving the vacuum inside the tank enough to keep fuel flowing. This problem seemed to be similar to vapor lock, but it would happen in cooler temps and regardless of fuel level in the tank. But I was ignoring the fact that recently I noticed that opening the gas cap to fill it , there would be a noticeable vacuum release and harder amount of effort to unscrew it after driving the car. So, hopefully someone else will test and try this instead of immediately going for the entire fuel system replacement routine we like to rush into. It just might be this simple.

Ok, here is the puzzle of the day. 1978 280Z, Daily driver In the last 2 weeks or so, I have gotten a starting issue. Car will fire up and then immediately die. This is not the 'very hot engine sitting with the hood closed vapor lock' issue. This can be at any time or temperature of the day(Texas). Things Checked:Coil,plugs, plug gap, spark from plug wires, fuel flow, fuel filter replaced, AFM 'fingered'. Car runs fine at all speeds and idle otherwise. My question is that this problem seems to be remedied by opening the gas cap after the start failure. If we open the cap, and crank, the engine can start. My thought is that a suction is created at the first start failure, and not allowing any more fuel to be fed to cylinders. I inspected the cap, looked at the spring valve, but nothing seems out of whack, but I am starting to believe this could be it. Has anyone else experienced this as a problem? Caps are cheap and I will get one. But wanted to know your opinions.... thanks.

Avoid the gnashing of teeth and go KIA sportage. Done and Done.

If you only knew what the original source wires look like leading to your 4 50 to 80 amp fusible links, you really wouldn't care how OEM it is. I'm not driving a Concourse de elegance.

What she said.

Finally got around to getting under the dash yet again. I found that the mode door actuator spring(driver side) was just dangling, off of the hook it is supposed to be connected to. The hook was missing 1 of 2 screws, which allowed it to pivot up and let the spring slip off. Added new screw and re-attached the spring. Now we are Blowing Cold and Fast! with no air going to the floor.

Hey guys, Could anyone else check your A/C when it is operating? Specifically I am wondering if you can feel any air blowing out of the side(heater) door next to the gas pedal when you have your AC Blowing cold. I think my air Mode Door is not closed completely and letting some of the high speed air out thru the heater door rather than getting the full velocity thru the AC vents. I need as much flow as possible! Thanks

Not my story, focus on temperature and pressure. The higher your fuel pressure is, the higher its boiling point is, just like a radiator. If the system does not hold pressure when its stopped, that gas boils, making vapor, and voila. No liquid. I've watched gas start to boil in ambient pressure at around 140F. You can believe its at least that when the engine is stopped after 10 minutes easy. Good luck with the windings.

To be clear, the fuel obviously vaporizes in the fuel rail and injectors, where the hot is(engine block). Mmkay? Not back at the pump. Once that happens, you are done until the fuel returns to the liquid state. That is the 'what' . As to 'why', various reasons all boil down to the boiling point of the fuel in your fuel system, which can be controlled by pressure, temperature, and fuel blend. Did I really type all that?

Zed, you funny Vapor lock - Wikipedia, the free encyclopedia

In all this discussion of what 'it' could be, don't forget the value of having a fresh distributor cap and rotor. They do wear out, and Datsun said to replace them every 12 MONTHS in the manual. That, combined with a fuel check valve after the filter has helped my vapor lock problems here in Texas about 90% better. And it is vapor lock ,people.

Your other option if you do not want to mess with your fuel pump is to go with an inline fuel check valve, say after the fuel filter in your engine bay. I did this to good effect until I'm ready to completely replace my fuel pump, which still puts out good pressure... You can try AZ or CarQuest...

AZ has a hand held tester they use for batteries and alternators. It does some digital magic to give them readings. For alternators it shows volts plus some other readings I didn't get to see Anyway, Thanks for your knowledge. I'll keep on running her