Roberts280Z

On my '76 non-CA Z, at idle, I have a very noticeable high-pitched Bronx cheer coming from the area of the BCDD. It's almost a buzzing sound. After reading everything that I could find, I suspect a rupture in one of the diaphragms. The sound will vary if you come off idle. The BCDD seems to still function somewhat properly - that is, holding RPM up for a bit before letting it drop. I could disassemble it to check the diaphragm(s) condition, but I don't think replacements are available, either for the diaphragms or for the entire BCDD. I'm aware that some have deleted the BCDD and plugged off the opening. Having said all that, I should add some background info. The car hasn't been driven in years, but the engine has been run several times in the last year. On a couple of occasions, after startup, it has run extremely rich (I have installed an AFR meter) with a very rough idle. Then, after 10-15 minutes, it will fix itself. A restart the next day will be fine. But if it sits for a few weeks, it may fail again. I mention this as full disclosure, but I sure don't see how a BCDD problem can make it run rich. So, any suggestions? Thanks in advance! Robert

I envy you guys who can do this. I was going to practice with my liftgate glass before trying the windshield, but I can't even do that. I'll give up and get a pro for both.

If you don't add a filter, then you're relying on the screen at the pump inlet, which is not easy to inspect nor clean. A clear filter gives you warning that you have a problem developing in your tank. I mounted my filter with a loop of aluminum tubing to avoid sharp bends in the rubber hose. I wrapped the tubing with heater hose to avoid chafing problems.

i recently used Red-Kote on a GM A-body, and I think it went OK. But I didn't think I would be able to use it on my Z because of the baffles in the tank. I took the tank to a shop that cuts access holes in the tank, cleans it out, and then re-coats it. It wasn't cheap - $550.

Thanks guys, Robert

This is an old topic, but not satisfactorily answered. I am trying to install new Front Door Seals I received from ZCarSource. These look much different from the MSA seals that were on there, and of course I can't remember what the original factory seals looked like. Here is a photo of the front of door, and of the seal layed on top for reference. I found some photos here (https://www.classiczcars.com/forums/topic/39768-front-door-seal-pics/?do=findComment&comment=357725) from 11 years ago. The replies conflicted - some said the rubber tabs tuck under, and others said they're glued on top. Also, the smaller rubber seal that I show encircled in red might not belong on there at all. Any ideas? Thanks in advance, Robert

The resistors won't drop the voltage until the injector is activated. I think in this condition (ignition on, not running), you should see full voltage on all injectors.

This is possibly what happened. Suppose indeed there was an extra, harder plastic cover, but over only the large opening at the bottom of the door. It cracked, and I made a replacement for it using the drafting mylar. And, while I was at it, I also made covers for all the other door openings.

Thanks for the suggestions for the watershield. Here is a picture of one of the smaller interior coverings that I had removed and saved, and temporarily taped for this photo: Note that it is yellow from a 20-yr old paint job. I had made these prior to that paint job from drafting mylar, which I thought matched the original material. Has anyone seen similar individual coverings, in addition to the overall watershield?

When I disassembled my doors, I just ripped all the plastic sheeting away, and assumed the FSM would help me with reinstallation photos. The FSM only makes mention of a 'water seal screen', with no diagrams or photos. The parts suppliers don't seem to offer any replacements. If it's just mylar sheeting, I can cut that out myself if I know what size it should be and where it should go. My doors also had individual thicker plastic covers over the individual inner door openings. It's possible that I added those myself, but I don't think so. Thanks in advance...Robert

i wanted a really fat wheel for my aging arthritic fingers. I cut down to the metal core, then encased in successively larger layers of heater hose, and finally wrapped in a custom Wheelskin.

I had a similar problem. I removed my water valve in order to free it up. But then I eventually decided just to inhibit all the coolant flow into the cockpit by plugging the lines, rather than risk anymore leakage. This is not a daily driver, and I'll never need a heater here in Houston.

Thanks for the suggestions. Of course today, the chirp has disappeared all by itself. I'll continue cautiously.

I use a 3' piece of vacuum line stuck in my ear for that. I had gone over the valve cover area to no avail. But I'll widen my search. Thanks!

This Z hasn't been driven in over 10 years. I started recovery by oiling the cylinder walls and cranking by hand. I eventually graduated to actually running it. There was a sporadic 'chirp' noise, which went away quickly. After some A/F tuning, I got a smooth idle, allowing a trial run around the block. But then fuel tank issues added a 2-month delay. Yesterday when I started it, it began well enough, then the 'chirp' noise returned and stayed. I then noticed that the noise occurs even when only cranking - occurring on every second revolution. I might assume this is valve related - perhaps a bent stem or otherwise sticking valve. Vacuum is dead steady, but I assume that only 'sees' intake valve problems. I haven't had the valve cover off yet, which I should do anyhow to check lash. But for this noise, I don't know what I would look for without removing the head. The last time I tried running the engine without a valve cover 20 years ago is still evident on my garage wall! Maybe I can get away with merely cranking with the cover off, but I still don't know what I would do, other than to try to localize the sound. Curiously, the only relevant search hit on this forum for 'chirp' noise turns up a question on the oil pump. Does anyone have an ear for this type of noise? Perhaps I could post a short audio/video file. Thanks in advance, Robert

I posted several pictures on Hybridz back in 2020 (Polyvance dash repair - Interior - HybridZ) Also, check out the Polyvance web site - they have a video of a 280Z dash repair. This was the outcome:

My dash looked very much like yours. I restored it using a plastic 'welding' kit, and I'm still happy with the outcome. I think I posted some pics on here, but I can't find them right now.

I patched those same areas myself. The quarter end wasn't easy, but I don't recall that there were good alternatives. The slam area was easier, but I probably would have used an available panel if I did it again.

'When you're working on solutions ask yourself why one rear wheel would stick but the other not if the problem was caused by the hydraulics.' That's exactly the situation I had. The flex hose at the wheel cylinder was collapsed to the point that you could force fluid into the cylinder by standing on the brakes, but it couldn't flow back out. This wasn't on a Z, but another vehicle that is 50 yrs old that had original lines and hoses. This was isolated by disconnecting the hose first at the cylinder, and then at its other end further upstream.

I've had that happen when the lines were plugged. Usually happens at the ends of the flexible lines. This would explain the dragging by maintaining some pressure in the slave cylinder.

That's a good point. I think all newer cars actually incorporate the A/C into the defrost function because of the dehumidifying effect. However, I suspect that the Datsun system would have to be modified to allow the chilled/dehumidified air to go through the defrost ducts.

Even after buying replacement underdash heater hoses, I decided to forego the heating function. If it's that cold, I won't be driving it. So, I'm just capping the heater lines in the engine bay with aluminum rods. I haven't attacked the A/C yet. It underwent a R-134 conversion about 15 years ago, but plugged up soon after that. If you still have all original R-12 components, but can't get R-12, I can tell you that I had reasonable success using Red-Tek in another car.

Did the brake linings look OK? When I had a similar problem in the past, the linings were swollen from leaking brake fluid. Were the shoes fully retracted? Only if they were not would I look for a problem in the master or slave cylinder, or whatever we're allowed to call them now.

Before you do that, you need to back off the adjuster. You should be able to find procedures for that on here. The brake-drum puller should be used only after you have done that.

I bought most of my weatherstripping from ZCarSource, except for the front and rear, which I got from Vintage Rubber as you are planning. The ZCarSource stuff seemed mostly OK, except for the door weatherstrip. I haven't yet been able to close my driver door. Vintage Rubber was the only place I could find that had that 'Cal style', which I wanted since I'm also black-powderoating all the chrome. I haven't mounted the front/rear glass yet.