1975 Datsun 280z daily driver (for now)

In reply to 2K4Kcsq:

Me too! It's pouring rain today, so no car work unfortunately. Hopefully tomorrow is better!

Nice. I'd suggest that you grab as much as you can afford to off of that car while it's there.

In reply to jimbob_racing:

Yeah, I'm sure I'll be thinking of more stuff I need in the next few days. I just want to get this stuff on my car and get mine going, then I can re-assess. There is a "Z junkyard" nearby too, it's just not always open and the guy is unreliable and kind of a rip-off. They do show up around here pretty often in the junkyard.

Got some work done today. First thing was to put the wheels & tires on. I discovered that one of them has a leaking valve stem, so I'll have to get that fixed, but the other 3 are on! I love the look of these wheels, I just need to lower it now. I'm thinking of using the Arizona Z Car springs, not sure of what shocks yet. Anybody have any recommendations? Here's the before and after.

All of the old exploded tires-

After I helped a friend move, I tackled the driver's window. When comparing the two regulators, I discovered that the front track was bent and the whole thing was just loose so it was binding. The window works pretty smoothly now, the only problem is that the splines for the window handle are a little gnarly, so I need to try to fix them or swap that part from the old one (not sure if that's possible). All in all it's much better, and it still retains the 38-year-old-car feel.

Now if I would just order my brake parts I could be on the road soon!

Did a few smaller things this morning-it's nice to check things off my list, even if they are not the most crucial items.

I started off by replacing the shifter bushings. There was so much slop in the shifter it was crazy. 2K4Kcsq made me some nice brass bushings, so I pulled out the console and pulled out the shifter. I would have taken a picture of the old ones, but there weren't any there! I guess they fell apart and out years ago. I had to sand down the bushings a little to get them in, and I took off a little too much, but the shifter is nice and firm now. Thanks again Jay!

I also replaced my turn signal stalk that also holds the horn grounding tab. The last thing I did was replace the fuel filter. I found a brand new genuine Nissan one in a storage bin the other day that I had kept from my last Z project, so I went ahead and put it on.

I also messed with the rough running a little too. Even with the air meter plugged in, it just won't rev up. It will rev (sometimes) to about 1500 rpm, then it drops off. If I rev it up very, very slowly sometimes it will go smoothly and then it just screams (the good kind) and seems smooth at high rpm. The air meter pops and jumps too. I'm thinking it's either the air meter is bad or maybe the TPS? I haven't dived deep into checking things, so it might be something obvious. Here's a video of what it's doing.

Z running rough

Anybody have any ideas?

Sounds a lot like what my 280Z was doing when I first got it running. It ended up being fuel starvation due to a rusty tank. Car would idle fine but when revved it up or I tried to drive it, I’d get a lean misfire out the intake. Try putting a fuel pressure gauge on it and see what it does when you rev it.

In reply to PseudoSport:

Hmmm...I hadn't thought of that. I've drained a lot of fuel out of the tank and put a new fuel filter on today and I didn't notice any obvious rust. Was yours really obvious? The weird thing is that when I first got the car running it idled great and revved up beautifully, very strong. I can't tell if this popping noise is a lean misfire, or if it's just a component (such as the air meter) acting up and popping and making noise. I'm going to dive a little further into this issue next-after all, there's not much point bolting other parts on if I have a serious running/drivability problem. I'm going to check timing, compression, fuel pressure, etc, just to get a good baseline, then I can go from there. Any recommendations will still be gladly accepted though.

Mine was not obvious. I spent weeks testing the compression, AFM, TPS, messing with timing, cleaning connectors, and tracing wires back to the computer. Fuel pressure at idle was good too. Revving the car from idle when it was cold showed shaky pressure but as soon as I left my driveway and put load on it the pressure dropped to zero. I even tried 2 different fuel pumps before dropping the tank but I did notice both pumps got noisy as I tried to drive the car. Didn't notice how rusty the tank was inside till i dropped it and looked down the filler neck. Once I flushed the tank with some acid from Home Depot and snaked the the 1/2" fuel line with a coat hanger it worked great. Fuel pump was now quiet too.

Here is what the bottom of my bucket looked like when I drained the tank

In reply to PseudoSport:

Very weird. I think I'll check my compression, fuel pressure, etc. to get a baseline, then I'll start inspecting that tank. I didn't have any sludge/rust like that when I drained it before, but I think maybe I should drain it again and see what I have now. I also didn't have anything like that in the fuel filter when I pulled it off, although maybe I should cut it in half and see what it looks like inside. Thanks for the help!

I'm gonna drain the rest of the fuel out of the tank tomorrow and see what I've got. I'm hoping that I have a bunch of rust in there, at least then it would be obvious what the problem is.

Looks great with the new wheels on there!

In reply to crankwalk:

Thanks!

I drained the rest of the fuel out of the tank this morning. It's definitely a reddish color, but I only had a small amount of sediment at the bottom. Now that it's empty, I think I'll go ahead and just drop it and check it out, clear all the lines with a coat hanger or something, then add some premium and some fuel additive and check fuel pressure.

I also got the hatch area cleaned out a little bit while the fuel was draining. I'll add some pics of all of this tomorrow. I really want to get this thing running by September, so I've got some work to do for sure.

while the tank is out, dump about a pound of short self-tapping screws into it, tape off all the openings, and shake it for about an hour. maybe even pour some acetone in while you're at it. the screws and shaking will knock loose all the rust & scale inside the tank, and the acetone will dissolve all the sediment / varnish.

or not. i'm the guy who said to put 55 psi in the tires.

Seth, I used the following to clean out a motorcycle's tank that was extremely rusty, and continually fouling the fuel system:

http://www.por15.com/CYCLE-TANK-REPAIR-KIT_p_59.html

They also have a car-sized system:

http://www.por15.com/FUEL-TANK-REPAIR-KIT_p_62.html

It is supposed to be ethanol resistant, which some of the others like Kreem are not, and has held up beautifully for the past 2 years on my bike. If you have the tank out already, the hardest part is done, it may be worth trying to acid-wash and re-line the tank. That'd be the end of tank problems, at least.

Here's the pics of what I did yesterday. There's a little sediment at the bottom of the bucket, but not much at all. I guess all it takes is a little to get into the lines, so I'll see what it's like when I lower the tank. That might not happen until next week, but we'll see.

The hatch area is in great shape, and it was nice to clean out the junk. The carpet is pretty much junk (the backing is all stiff and cracking and it's really threadbare). But it works for now, and it will look better once I can attack this thing with a vacuum.

Thanks for the info on cleaning out the tank guys, I need to decide what I'm going to do!

Before dropping the tank did you test fuel pressure? Also when i drained the fuel from my tank is came out clean. Its when i tipped the tank and drained the rest out the filler neck is when all the rust came out.

As for the sealing the tank I'd advise against it. There is a screen built into the pick up in the bottom of the tank. If you seal it the screen will get clogged and make things worse.

Picture of the screen: (not mine)

Mounted in the tank with a baffle

In reply to PseudoSport:

No, I should have checked it, but I didn't have a gauge and I was really curious if I'd get some big chunks out. I think I'll drop it out and check things over, blow out the lines with compressed air or snake them with a coat hanger, then put it back together and see what I've got. Probably add some Sta-Bil and premium and then check fuel pressure. I figure it's a win-win...if it runs well, then I've fixed the problem. If it still runs crappy, at least I have a clean tank and lines.

Any particular method you recommend for cleaning it all out?

I started with muriatic acid mixed with water to clean most of the rust out of the tank. The acid is pretty strong so make sure you wear heavy rubber gloves and don’t breath in the fumes. It worked well to clean the tank but would flash rust within minutes of draining the acid out. I then used phosphoric acid which took care of the flash rust plus it leaves zinc phosphate coating which helps protect the metal. Even after the acid cleaning when I filled the tank up with water it would only trickle out the ½” fuel outlet. Once I snaked the lines and removed a bunch of rust and varnish, water flowed out fine.

If I was to do it again I skip the muriatic acid and just use phosphoric.

This is the stuff I used from Home Depot

http://www.homedepot.com/p/Klean-Strip-1-gal-Phosphoric-Prep-and-Etch-GKPA30220/100406369

In reply to PseudoSport:

Awesome, thanks for the info! Hopefully I'll tackle the tank removal next Wednesday, it ain't gonna happen this weekend.

sweet man, glad those bushings worked out for you. as for the tank cleaning/coating, i did the por-15 system on my z tank and it has been trouble free ever since. i understand the concerns with the coating clogging up the sump but i just made sure that didnt happen by spraying compressed air backwards thru the feed line while the coating was still wet. like i said, 3 years and many miles without any issues. also, if your just looking to clean it the marine clean that comes with the kit can be bought seperatly if you dont want to do all three steps. my thought was, it's already out, might as well do it all. good luck with your running issues, i'm sure you will get it all sorted out. wheels look great! everyone has the wheels i like but me! lol

Awesome thread....I hope you never lose interest in your z project and see it through to the end

Thanks guys! I think since I'm cheap (and like to live on the edge), I'll probably just drop the tank and clean it out and not coat it. TIme will tell if that turns out to be a good idea.

Got some good work done this morning. I dropped the tank, and just as PseudoSport suspected, I had a tank full of rust. I rinsed it out a little with the old gasoline that I had, and I'll try to do the acid cleaning this weekend if I have time (gotta work on the family CR-V on Saturday too). I also ordered brake hoses and wheel cylinders the other day, so things are moving right along! Even if the rust isn't THE problem, it is definitely A problem.

Now I know why the gas gauge didn't work...rusted solid.

Here's what I ended up with after rinsing. There's still a bunch in it, but this is a few handfuls, at least.

And a view of the other side of the car-it seems all my pics are of the driver's side.

Man I love how clean this chassis is!

Yeah definitely run a fuel filter (the biggest ones you can) right after the tank and up front.

Mine was redone in the 90s some time but STILL had a bunch of sediment in it and I had to empty that rear filter a fuel times.

That definitely needed to be done. Keep it coming!