Pomorza

Guys, I have learned this the hard way in my Z. Vapor can happen (can) if the system is not completely isolated. This is what i mean, if you look at the fuel injection system as a pressure vessel (in our case at ~40psi), there is no chance for air to get into said system if it is seal. With it sealed there fule has neither the space or the needed air to vaporize. But if you have a leaky injector, bad check valve, or an assortment of aother issues pressure will not hold in the system. Once the system's pressure is low this gives the fuel enough room (and air in some cases) to vaporize and thus cause "vapor lock." That being said, when does this "stumble" occur? Is it during driving, during idling, when you first restart the car when hot? The only time I've ever had problems with vapor lock was when I let the car sit after a drive (a longish one). On restart the car would run really lean for a few minutes and then drive fine the rest of the time. Hope that help Jan

I don't know if anyone asked this but do you have a fan shroud? I know people that believe these don't do anything but they do indeed help cooling the engine. Check the fan clutch also as stated above Jan

R's have a resistor in the plug that, for what I've been told, reduces the amount of electrical noise given off by the plugs. I'm sure there's other reasons but that was the one I was given by a few people. I've never run anything else but NGK's in my Z or any other L motor at that. They're not too expensive and don't seem to give me any issues at all. Hope that helps Jan

The large thing there is the center under the crank pulley is the oil pump. It's more then likely not leaky coolant, its probably leaking from above and coming down all way there. If you look at the top left of the picture you can see coolant sitting on one of the bolts up there. Something above there is leaking. Check the water pump, hoses and all the fitting that the hoses go to. Hope that helps Jan

deadflo, Blue described the basic process. I did this about a year ago and took a few pictures if you'd be interested.

LeonV, Correct me if I'm wrong, but just because compression is even on all cylinders does not necessarily mean that the head gasket is good? That being said I have seen aluminum heads have pin hole leaks in the water jacket which causes water (coolant) to leak into the combustion chamber and thus causing the said issues. Either way the head should come off to see what the problem is.

Jim, What kind of miss? Is it a miss fire as in the engine, (poor firing, hesitation type thing) or is it in the intake (like a popping noise). Both are never good but if its the latter (popping in the intake) you maybe running lean. Remember just because you have propper fuel pressure does not mean you have propper volume of fuel entering the combustion chamber. With old FI system like the one in 76s (I have one) the electronics tend to fade over time and lean the heck out of the mixture. To really understand how the old L-jet fuel injection works on Z's I've included a link (TADA). Its of an old manual I found someplace on the net when I first got the car. I used it constantly when I had the old L-jet system to make the car run better. I finally had it set and running the way I wanted and then the wiring finally started taking a crap:mad:. Go through it and see if you've done everything suggested. For reference, throwing parts at a miss with these cars rarely ever fixes them unless you know exactly what the problem is. (I learned that the hard way) Hope that helps Jan

Guys, So here's a question. Going of what Wade said in the post above, I could use a standard one wire capacitor instead of the one that Datsun used correct? I ask as at the moment my car is not getting spark period, none, nada. Its not helping my injection system either (aftermarket) as its not getting a tach signal from the coil. I don't think the actual condenser has anything to do with it but I don't like using 30+ year old condensers with brand new coils and dizzies. I was looking at just getting this one from autozone earlier in the weekbut chose to use the one I had found at the junkyard. That being said I chose to use the stock coil to see if the ignition problem I was having was coil based or something different. Sadly it was the "something different" case, now I just need to figure out what. Thanks for all your help guys Jan

Thanks blue. The capacitor had two black wires coming out of each end. There's nothing on the case color wise and the only writing it has is "c-122 250-0.47 Sy" if that tell you anything. I'll have the fire extingisher ready just in case the thing explodes. Thanks Jan

Thanks Blue. I use it for a slightly different reason but basically I need to get rid of the electrical noise in the circuit. I can't really tell you which side of the condenser is postive and which side is negative. I wired it the same way mine was wired. I haven't run the car yet as I would like to make sure I did it right. What could go wrong if I have it wired backwards? Thanks again Jan

Hello all This past weekend I was changing out the coil in the Z with a stock unit; the blaster II coil is great (MSD) but sadly I'm tired of going through rotors every few months. Well in the process I unplugged the condenser that sits atop the coil mount. The wire that connects it to the coil broke off from old age. I spent the large part of this week searching endlessly for a new one. Sadly the only condensers I could find only had one wire and not the two that the one in my Z has. I ended up going to the local wreching yard and pulling a rather nice looking condenser out of a late 70's maxima (I want to say it was 79). It looks exactly like the one I have in the Z and has the same values. So I have a few questsion for you all. First off, is there a reason that it is grounded? I ask as the condenser, accordoing to THIS is connected to the positive side of the coil. I was alway lead to believe that the negative side is the ground on things. Secondly does anyone have any idea where one could get a new one of these? Thirdly, since I have a "new" one that I pulled out of that maxima (810) does it matter which way it goes? Its not labeled + or - anywhere that I can see. Thanks for all your help guys, Jan

Are you sure its the fan clutch that is whining, could it be anything else? I don't believe I've personally ever heard a fan clutch whine. When they break they tend to just lock up and you're fan will always be on. (and the car will sound like a jet driving down the road).

Good point there mjr, copper spray does work if the gasket is in good shape. It all depends on condition. When I did mine a few years back I put RTV on the whole top of the cover and I haven't had a leak yet. When I did my brother's I did the same thing and oil leaked out like a siv. Jan

The fuel pressure gauge is a standard mechanical gauge that's positioned right after the fuel filter. The fuel pump is a stock 280z pump thats new. (i bought it from MSA about a year ago maybe). Thanks Jan

When my Z was running I drove it up and back from Phoenix in 100+ degree weather. The thermostat housing read 190 when I pulled into my parking lot. (Don't ask why I was checking). I ended up swaping to a lower temp thermostat as it started creeping into the high 190's on mountain drives (that was from the sensor, I actually registered 197). I'm not a big fan of the head hitting temps above 200 as they're aluminum. Its a personal preference, it runs at about 170 right now after some mountain fun. I know I have a different car (a 280 in my case) but I lack hood vents and I live in Arizona, where it gets hot (right now its 105,). I do find it weird that your car cooled 20 degrees when you idle in traffic. I would think that with the amount of air crossing that radiator at highway speed it would run cooler and not warmer. Hope that helps Jan

Grantf That's a normal problem when you do the front cover. (I've been told anyway) I had to do my brother four times before I got it right. This is what I ended up doing. I pulled the cover off again. (for the fourth time). I cut the old head gasket where it would mate to the top of the front cover. (carefully) Then I purchased a new head gasket and cut the front of it off to match the one I pulled from the motor. I then placed the new head gasket atop the cover and covered both sides liberally with copper silicone (RTV its copper colored). Then I put everything back together and I have no leaks. It sounds like a PIA but its the only way I've found that works. I've tried using anaerobic sealant between the cover and the head gasket with no luck. I know it sounds like a complete PIA but I think you're going to have to do this AGAIN to fix said oil leak. :mad: Hope that helps Jan

Hey guys Today I replaced the negative battery cable and the starter on my Z. (Gear reduction starte, and it was free.) I started working on my Z I swear that the fuel pressure gauge I have read 0. I have the fuel pump and other things connected via a terminal board directly to the battery. I say this because this is what occured. Everything was unplugged from the battery minus the negative cable (big mistake) I was struggling to maneuver the postive cable into place when I accidentally arched it on the engine (side of the block). Sparks flew I was all sorts of freaked out but ok. Unplugged said negative side of battery and connected everything as it was before. I look over at the FP gauge and it reads 30. I'm confused. The fuel pump was off, there's no way power was getting to it as the terminal board (which has an inline 30A fuse) was not connected to the thing, key was off (locked) and the kill switch on the fuel pump was off. How in lords name could I have fuel pressure? I know its possible I misread the gauge (which is what I'm thinking I did) but can anyone think of a way that I went from 0 pressure to 30 by what occured? Thanks Jan P.S The car does start and run fine. Didn't drive it as I'm having noise issues (electrical noise) but it does run.

Irish, You can do the honda blower motor swap on a 280z yes. You do need to "modify" the blower housing by cutting out the hole bigger but once it's big enough to fit the new honda motor it works great. I noticed a minor difference but it was worth it if you ever plan on replacing a bad motor (which was why I did it in mine). All you need is something to cut the metal in the housing. I used an air power saw which cut through it like butter. Jan

Hey guys, So I found a 12 volt source but do have a question. What exactly makes this a "switched" source. Is it the key itself or is there a relay someplace. If the ignition was going bad (the key that is) could this cause fluctuations in the voltage output? Thanks Jan

E. I searched every free wire in the radio area and there's not a single one that is switched. There were two that were constant 12 volt sources but none that were switched. Any ideas? Anyone?

Hey guys, I'm planning on installing two new gauges in the Z but am having a hard time finding a 12 volt switched (i.e car has to be on) source. Any ideas? Thanks Jan

Hello all This past weekend I did a tune up in the old Z, new plugs, new wires new rotor. (the cap looked new). I have a MSD Blaster II coil along with a ZX dizzy (81 I believe). I'm having a miss fire under really all conditions and haven't been able to figure out why. I've checked the gap, resistance of wires (and the cap) along with the coil. Is there a way to test the "match box" (black box) on the ZX distributor? Thanks all Jan

Dan, Thanks for all the help. I did indeed figure the problem out. The number 1 pison was not firing as the injector connector didn't work, cause an extreme lean condition at times and a rich one when it did actually fire. In short it confused the hell out of my fuel injection computer and lead to a myriad of issues. Thanks for the help though mate. Jan

Hey guys, I drove the Z around today. In the morning all was good and dandy. Later this afternoon when it was nice it hot outside (100 actually) I drove down on the freeway to get back to my house. Everytime I let off the throttle it felt as if my car was braking (or being pushed back...er hesistating, I don't know the best way to describe it but it would literally feel as if I had hit the brakes or something had excessive drag). It does it in every gear it feels and I don't really know what it could be? Any ideas? If its a fuel issue I can fix that, but it just doesn't seem like that to me, it seem more of a mechanical type of drag. When I got home I checked all the rims of my car for heat, all four were rather hot to the touch but it is 100 here so I don't know if that changes anything. Thanks Jan

Hello guys, In the past couple of days I've noticed the Z has low oil pressure at start-up when warm. The first time it happened the gauge sat at about a quarter for a good 2-3 minutes before it shot up to the normal oil pressure. Last night I started it and it sat there for a few seconds and then rose. Any ideas on what it could be? I did an oil change yesterday as I was thinking it was an oil problem but nope still has it. On another note, what could cause a squeaking noise when the car first starts when warm? Belts maybe? Can exhaust squeak? Thanks Jan