[Triangle]

Hi all, glad to find this forum! I've owned and raced many Mustangs, but this is my first Datsun. I also have a 95 Miata and a 70 vert mustang coyote swap that is a long way till done. Anyways, I just picked up an original owner 83 280ZX GL turbo. The car starts right up and runs great. Before running it further I am

• changing oil to a Zinc heavy 10w-30 conventional (better than synthetic mobil 1?)
• changing AT fluid (should I use synthetic?)
• changing brake fluid (Dot 3)
• removing interior and inspecting/repairing wiring

The car is all original and only has 94k miles and mechanically seems to be in great condition. The interior, however, is pretty shot. It looks like it would get moist in the winter and then get hot and warp in the summer. I've started digging into it and noticed quite a bit of moisture under the carpet so I'm taking everything out to dry out and check for rust. So far any rust appears to be minor surface stuff. I just pulled the passenger seat and all the wires (and computer?) look brand new and not corroded either. I'm not afraid of cutting and welding patch panels (will definitely have to do spare tire well). Its a CA car so I'm hoping I won't find much though.

The issues

• Digital gauges won't come on
• only the boost gauge works
• some rubber sealing surfaces are leaking (to be expected)
• AC doesn't work (compressor does not engage)
• Headlights don't work (when I turned them on I got a quick little curdle of smoke coming out of the column so I quickly turned them off)

The car has sat for 12 yrs in the SoCal sun. I just want to refresh her back close to original and leave it at that. The car is a total time-capsule and I've got other modified cars to scratch that itch. She just needs a bunch of hoses replaced that are obviously cracking (but holding still). She starts right up and idles smooth and quiet. I've been reading a lot on this forum and others but I'm still getting acquainted w the Datsun world.

My main questions currently are

• any tips for resurrecting the digital gauges or where to start?
• Are any circuits in particular prone to shorting out?
• Is there a source for vacuum and egr hose replacements? (I haven't found many avail so assumed generic was the solution)
• I've found some replacement cooling hoses for sale, but only for a few of them. Any better/complete source for these?

Thanks in advance for any help/advice!

 

[pilgrim]

I can't help with all your questions but I can answer some of your questions. I also have an 83 ZX Turbo.

• changing oil to a Zinc heavy 10w-30 conventional (better than synthetic mobil 1?)
• changing AT fluid (should I use synthetic?)
• changing brake fluid (Dot 3)
• removing interior and inspecting/repairing wiring

Oil - the major synthetics like Mobil 1 and Amsoil are fine. I have used them for 30 years in my ZX, mostly Mobil 1 because it's readily available.

AT fluid - you may get different answers on this one. I'd probably stay with a conventional ATF that's rated for the vehicle. You're not likely to be putting a lot of miles on it anyway.

Brake fluid: DOT 3 would be OK, but I use DOT4. The difference is a higher boiling point, so DOT 4 is more resistant to brake fade. This may matter if you do autocrosses.

Given the car's background, the wiring should generally be OK. The Engine Control Unit (ECU) is behind the kick panel on the outside of the driver's side footwell. Not sure that the box under the passenger seat is.

I have used generic vacuum tubing on my engine. It doesn't like vacuum leaks, so that news that yours runs smoothly is good to hear.

 

[Triangle]

Many thanks! That's very helpful info. I just need to get a steering wheel puller and get into the cluster and clean every electrical connection and see what that does. I see a lot of people switch to the mechanical gauges but I'm determined to keep the digital ones. I've also read some tidbits that you should "change all the bulbs." I'm not sure if this includes headlights/taillghts or just in-dash bulbs.

Its interesting to have a car that doesn't have as big of an aftermarket. I guess I was spoiled coming off a miata.

Boy does this car have a lot of little rubber hoses. They all look pretty beat up too.

 

[pilgrim]

The 280 ZX turbos are a nightmare of vacuum tubing. Everything they do now with a few electrical wires was done then with vacuum systems. I spent a year fighting my ZX when it ran rough after having the head off. I finally took it to a shop where there was an actual Z mechanic and turned him loose on it. 90% of the problem was vacuum leaks.

Keep careful track of where vacuum lines begin and end, and keep in mind that some of them are hiding under that d&*#$^ intake hose where they're difficult to see or work with.

 

[Triangle]

It really is a dizzying amount of vacuum lines and t-connectors. I guess I'm lucky to start with everything engine-wise working properly. I have not tried a WOT run so not sure if its all gravy under boost. I ran the car long enough to determine it ran and sounded healthy but I am waiting to change fluids and tires before giving it a real romp.

Under the intake hose, you mean the inlet from the Turbo to the throttle body (black metal tube)?

Thanks again for the info!

 

[pilgrim]

I refer to the large hose goes from the air meter next to the radiator, back to the metal intake for the turbo.

My suggestion is to replace one vacuum hose at a time so that you can keep them straight and sorted out.

 

[bonfire79]

Yes, those darn vacuum lines. They are usually the big culprits and many times this is the last thing that some folks even consider. My Z31 AE T has so many vacuum and coolant hoses its ludicrous. Fortunately your 280zx engine is a bit easier to access most of those stupid lines. And I second Pilgrim on the DOT fluid. I use DOT4 over here in UAE since its all I can ever find at the stores for some reason. Works well on my Z.

You can't go wrong by switching out bulbs inside the cockpit. I like to replace mine with bulbs from 'superbrightleds.com, they will give your dash a nice new look. But if you like the nissan orange that's cool too, just be mindful that the little orange bulb cover thingies aren't available anymore if memory serves me right. Don't waste money on exterior bulbs unless they aren't working. If anything replace the headlight assembly lights.

Is your digital dash display not working? If so fear not. The Z31's have this as a common problem on their digi dashes. The fix is to repair the power supply (on the Z31) I would think the 280zx has one as well.

Bon

 

[pilgrim]

It's also possible that @zmanofwashington may be able to share info about the digital dashes. I hope this flags him...

 

[zmanofwashington]

The digital dashes in the S130's don't use a power supply box like the Z31's do. Trying to fix the digi dash is a nightmare and you'll be in the dark trying to fix it. There is zero information on them available. When the zx first came out with the digi dash setup, Nissan didn't release any info on it to the technicians and that continued on to the end of the 280 zx's. If you have the digi dash then you also have the auto ac or Climate Control. Both the Climate control and the digi dash are a complete waste of time to try and fix. Zero parts are available new for the digi unit or the climate control except maybe the heater control valve. You're better off simplifying the car by converting it to analog dash with manually control HVAC. It's almost all plug'n'play to do the conversion and it will still be stock. If you do both conversions you'll be getting rid of multiple sensors, multiple control pods, and about 10 miles of vacuum hoses. Once it's done you'll be able to see the tach and speedo even in direct sunshine, and they will be more accurate. Even your gas gauge will work better by comparison. Z man of Washington

 

[bonfire79]

Zman, you are such a wealth of information! a Z blessing in disguise. Thank you! I was not aware that the ZX didn't use a power supply. I wonder what they used to run those dashes? Its a shame that Nissan didn't write any info on these things especially when it comes to troubleshooting them. I will definitely plan on doing a swap if I ever get a ZX car with the digi dash auto climate setup. Sounds like a nightmare. Also, did you ever get your 130mph speedo online? I still want one!

Thanks as always for your info and insight.

Bon

 

[arcticfox]

On the digital dash in 280ZXs...

I used to have a 1983 with digital dash and the problem (at least in my case) was a fuse that's actually attached to the back of the display that blew chronically. (I only knew this because I was a tech at a Nissan dealership at the time and had access to lots of juicy info)

So the annoying thing was that the fuse would blow on a semi-regular basis. There wasn't anything wrong with any of the components in the dash, it was just a fuse that was probably too low for the circuit. Even so, I never had the guts to put in a heavier fuse, since I decided I'd rather replace the fuse periodically than risk damaging something really complicated.

Getting the digital dash out wasn't easy but after you do it a couple of times you figure out a trick or two.

 

[Triangle]

Thank you all for the info! I've removed the gauge pod and discovered a lot of corrosion inside of it. Its a rust free car for the most part, but there were leaks intruding into the interior and one of them clearly was dripping into the gauge cluster. I did completely disassemble the gauge cluster. I checked for the fuse soldered onto the back of the fuel gauge (i think) but mine was not blown. I scrubbed all of the connections and cleaned off the corrosion but it has not come back to life. You can see the burned looking corners on each of the readouts. I would assume they aren't supposed to look like that?

I know the analog conversion is better and maybe I'll end up there, but for now I really want the digital gauges to work and am determined to have them in the car not only for originality but because they are hilarious. I've heard they are dim, but there is a HEAVY double layer of tint on top of them. If that tint was removed they might end up painfully bright. I did buy a known working set of gauges so I'll be able to see if the modules looked burned like these. And honestly, I'll be happy if they are just ballpark accurate when working.

I did hear about the auto climate thing and haven't read up on it yet. Can I have digital gauges AND analog climate, or does the harness not support that? My climate control will only blow on the defrost setting and doesn't seem to get hot. Losing 10 miles of vacuum hose sounds great too. This car has plenty to spare.

On the plus side I was able to resurrect the oil pressure gauge, the headlight/brake lights and the auto locks.

The items still not working

• talking lady
• turn signals/hazards (no clicking or lights)
• oil temp gauge
• A/C and climate control (other than defrost)

 

[Triangle]

A few more pics

 

[Triangle]

I made some more incremental progress. I was able to fix the hazard switch. There just isn't much info anywhere on this stuff. All one usually finds are solutions like "replace the flasher" or "replace the hazard switch." I'm more interested in fixing things first, replacing as a last resort. I guess I've been spoiled working on more mainstream cars like miatas and mustangs.

Case in point, I disassembled the hazard switch (bent the 6 tabs out), once pulled apart its extremely clear what the problem was (corroded contacts). I sanded them down and reinstalled the switch. Now the flasher unit clicks and the hazards work. After seeing the inside of this switch, there just isn't anything that can "go bad." Certainly not worth a $99 ebay part when it took me 5 minutes to fix mine. (pics included)

My car seems to have a single "flasher" since I can only find one unit in that area. Its a black box labelled Niles SF 112 it was attached to a small bracket behind the steering column (above brake pedal)

So now my hazards work, but still no turn signals. I disassembled the combo switch with the turn signal stock. I sanded all those contacts down but no luck still. I can't find a second flasher unit buried in the dash but as far as I've read there are always 2 of them (one for hazard, one for signals). My hazard flasher has 3 pins fwiw.

 

[arcticfox]

If you've got the wiring diagrams that may offer some insight into where to look for them.

Rootin' for ya. I love the digital dash.

 

[pilgrim]

Man, I love it when a guy is willing to open up a switch and fix it. WELL done!

Memories: I had an Audi 200 in which the lights went out in 3 of the 4 window up/down switches mounted on the door armrests. Instead of paying $60 each I removed then, opened them up, replaced the tiny bulbs and re-installed. Cost me most of an afternoon but I gained skill and corrected the problem, saving $175. (The replacement lamps came as a $5 pack if memory serves.)

 

[zmanofwashington]

Bonfire, the zx speedo that I'm going to be selling is actually a 200 MPH unit with the KPH on the inner circle which by the way is 335 KPH. I still haven't locked in a company to make me new needles yet because I haven't had the time to pursue it further. It will happen though. ZMOW

 

[Route66]

Triangle,

Years ago the digital dash on my Z31 ('88 300zx) would intermittently "go out." Somebody on one of the early days forums figured out if you jammed a matchbook or piece of cardboard up under the dash where the harness plugged into it, the problem went away. Turns out that over the years the solder around the prongs that received the plug had "dried up" and shrunken. So by jamming something in, the plug was wedged back into contact. It all made sense because the problem was much worse in the winter.

The solution was to flow some fresh solder into where those pins were. I've got a 2000 Toyota 4Runner that suffered a failure in the digital climate controls, and the problem also turned out to be solder that had shriveled up. I would inspect the main plug where the pins are and any other areas that look like the solder might be a little puny. The technology and build techniques from 1983 to the Z31 model was probably still very similar.

I really liked the digital dash and auto climate on both my ZX Turbos, sure do miss those cars.

 

[bonfire79]

Bonfire, the zx speedo that I'm going to be selling is actually a 200 MPH unit with the KPH on the inner circle which by the way is 335 KPH. I still haven't locked in a company to make me new needles yet because I haven't had the time to pursue it further. It will happen though. ZMOW

That's great. I'm looking forward to it. Once I get my 280zx project build going, I will plan on getting with you about the speedo. Hopefully by then, It can be close to completed. 335 KPH is fine with me... I drive 160 KPH over here all the time. Too much fun haha

Thanks, Zman. Appreciate ya

Bon

 

[Triangle]

Triangle,

Years ago the digital dash on my Z31 ('88 300zx) would intermittently "go out." Somebody on one of the early days forums figured out if you jammed a matchbook or piece of cardboard up under the dash where the harness plugged into it, the problem went away. Turns out that over the years the solder around the prongs that received the plug had "dried up" and shrunken. So by jamming something in, the plug was wedged back into contact. It all made sense because the problem was much worse in the winter.

The solution was to flow some fresh solder into where those pins were. I've got a 2000 Toyota 4Runner that suffered a failure in the digital climate controls, and the problem also turned out to be solder that had shriveled up. I would inspect the main plug where the pins are and any other areas that look like the solder might be a little puny. The technology and build techniques from 1983 to the Z31 model was probably still very similar.

I really liked the digital dash and auto climate on both my ZX Turbos, sure do miss those cars.

I did read quite a bit about the 300ZX digital dash system. Those newer (awesome looking) gauges have a proper power supply and yes, it looks like a shim or just by re-melting the contacts it could be fixed. I haven't found a similar unit in the ZX unfortunately. Its a strange design because the power supplies appear to be integrated into the individual display units. If you look at the pics I posted you can see the burned looking circles inside of the glass display part. Each display shows the burn marks. I did order a working digi dash off ebay and will take it apart and see if those burn marks are there which will be a major clue.

I'm having a blast taking all this stuff apart and trying to figure it out. Its my fav part of working on cars, all the little puzzles. Thank you all for sharing your experience and knowledge!!!