cozye

Is the bolt stripped? I'm not sure how it would have loosened up enough to leak if you had just replaced the gasket. If its leaking at all it will only continue to get worse as the host exhaust gas burns what's left of the gasket out. I'm afraid you will still have to pull it all off, install a new gasket, and install helicoils in any stud that has weak threads. While its off, check the manifold for cracks and for warpage on the mating surface

The 280 doesn't have an maf. It has an air flow meter that is not adjustable. Unless the AFM is broken, or someone has cracked the case and messed with the calibration it is not likely the issue. Download the fsm and perform a full efi diagnostic. Common sources for running rich will be the water temp sensor, fuel pressure regulator, cold start injector/thermotime switch. If full system check yields passing results you can follow blues tech tips page to recalibrate the AFM, if someone has messed with it before.

Another test you can do to gets more info, pull a vacuum line off the manifold when running cold to see if it helps or hurts. This will introduce more unmetered air. It does sound like your aar could be acting up, although I know you said it was replaced not long ago

Not directly related to cold start, but it is related to cold weather. There is a cut off temp that it riches the mixture up. It's described in the fsm. I don't remember the temp, but it's like 59 degrees or something like that. I could see a possibility that that if it were not working, you would be lean on cold weather. It's a long shot but worth checking. Does the car run good when warmed up?

Did it stop ticking when you removed the plug wire to #6 ? I think that's the key here.

The hubs on the 280 are a bit thicker on the taper. I had the same issue with konig wheels and msa swears they should fit. I did my own research and dug up some discussion for grinding a little off the hubs. This is what I did. If I where to grind off the taper on the inside of the wheel, the center caps would not fit. The amount needed to grind off the hub was very small and I'm sure it's fine. Took 15 minutes.

Poor some seafoam in while running and see if it blows smoke out the suspect area

Didn't you check the manifold for warpage or cracks? Some owners have to get the manifold milled down to straighten the maiting surface.

Yeah, I'm betting water temp sensor as well. If not, also check the intake are temp sensor.

I suppose the going away when hot thing is possible, but that's not the norm. On these cars the end bolts like to snap off due to rust, heat, and warpage. Especially on 1 or 6 at the end. It's not too bad a job if you take your time, use lots of heat and pb blaster. Don't get impatient and work the bolts slowly back and forth very gently. Nissan still makes the gasket, which is higher quality than the replacements

No telling without details. I would guess somewhere between $2-8k, with the high end only being an exceptional show quality car.

Definite exhaust manifold leak. It's common. If it where a valve train related tick it would do it whether you had combustion or not since the cam is still spinning and opening th valves

I've done it. The brackets are the easy part. You have to drop the fuel tank to get the old bumper shocks out, then you have to cut the rear filler panel off with a grinder and shave the rear. The you have to weld in sheet metal to cover the big holes in the rear apron, you also have to grind off about 10 spot welds then hammer them in a bit and the use your body filler. It's not difficult if you are comfortable doing that stuff, it took me about 20-30 hours.

It doesn't tick when the plug wire is off number 6?

Resistance, ohm, depends on the brand as to how it's labeled. It's really easy.

Running rich sounds like a coolant temp sensor. Use test procedure in fsm to check

What size tires?

Nice. I wonder how much of a difference it will make? I elected not to replace mine, but I wonder if I'm missing out on less wind noise or something?

I've heard that the mark can get off, forgot exactly how. Either the pully slips or something like that. Like some cars have the rubber piece between the harmonic balancer and the pully, i can't remember if the z is like that. In any case, pull #1 plug, use a wooden dowel in the plug hole to get any accurate measurement of TDC, then make a new mark at 0 on your pully. Use some white paint

Pics? For what it's worth I've done a mild restoration on a very solid 280. Just had it appraised for insurance purposes. The appraiser put it at $20k, which I thought was high but it's fine with me. It was a well documented appraisal based on collector car auctions, ebay, other references etc.. Other cars referenced were in the 6-14k range but not in as nice of shape as my car. The insurance company disagreed and is only willing to insure the car for $15k (which is what I'd like to have it insured at anyway). I've got about 15k in it and have done most of the work myself. All that being said, do I think I could sell it for $15k ? No, I don't. 10k maybe.. Do I think I could buy one just like it for $15k ? Probably not. Unfortunately the 280s are in a weird place. There aren't a lot of really nice 280s available, and most z car guys would rather have a 240. Supply is low, but demand is low as well. Even a really really nice 240 rarely sells above 15k. Now if an old lady in a caddy tbones my 280, is 15k going to be enough to keep it from hurting my feelings? Probably not. Bottom line is that the car is worth the most to the owner. Hopefully you can "document" it's value to help protect yourself, but in reality the z cars in general are not going to sell for a large amount. This is both good and bad. Bad if you are a seller, great if you are a buyer. The saving grace is that I think you can insure the cars for a very fair amount as long as you have it professionally appraised. I certainly don't want to be fighting about the cars worth with another drivers ****ty insurance company after the fact

Looking good!!

I thought so. Can't believe it still leaks

Didn't you also replace the side seals on the oil leak?

My 78 isn't sloped.

I wish I could find the larger ones for the 280