S30Grit

280Z Requires Starting Fluid for Cold Starts

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    I was going to mention this earlier.  Others have noticed that some ignition switches have a break between Run and Start and others don't, I think it was early compared later.  Can't remember which is which, old versus new, but I think that SteveJ @SteveJ dug in to a bit.  If I recall, it was decided that it din't really matter much.

    Corroded connections can open up once current starts flowing and creates some heat.  You've found a potential cause for your problem, or a potential cause for some melted wires in the future.  Keep cleaning.

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    yep just keep cleaning, If you find anything at all like that in any of the EFI you will have problems. I assume you have taken a close look at all the injector/AFM/other sensors and looked for any blue/green stuff. It all needs to be clean. the thing about the early EFI is they are dumb in that there is no learning or compensation going on. It like wearing blind fold while some one guides you thru a maze. If the person yelling out directions is not optimal you will be banging into walls.

    Edited by Dave WM
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    Yeah, I have cleaned all the sensor connections key to the EFI system.  Some definitely needed some attention.  A couple have broken tabs that likely need to be replaced, but I think it's only CSV and thermotine that are broken, so technically if those don't connect up perfectly, it should be fine for the short term at least (except for when CSV would be needed).

    I drove it for the first time this weekend.  It seemed to get a little warm towards the end of a 20 minute drive, ~75F outside (of course I hit every red light and prob averaged like 10mph  #bayarea).  It took a while to get there, but at the end of the drive it was around 3/5 of the temp gauge.  Not boiling hot, but I'm assuming the car is supposed to be about 1/2 during normal op temp.

    I've got a lot to do, big items are:

    • Track down a short to ground in my hazards circuit... blinkers/hazards aren't working.  I saw there's some wiring that goes to the engine bay is wayyyy up in the dash.  No idea to get there yet, but would be great to check those connections.
    • Trace down this starting issue, or I have an empty switch in my cabin that I could wire up to the starter instead of troubleshooting, which I'm tempted to do if all my wiring looks "fine"..
    • She ran great response and had good pull up to around 3k or 3.5k, but after that she just seemed out of juice in each gear, barely gaining in revs, even with pedal to the floor (just testing). Wiring or AFM or something...
    • One of the main fuse-box wires that goes straight to the battery (and has a fusible link) has a couple KOhm of resistance in it somewhere.. Prob another wiring issue there.

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    27 minutes ago, S30Grit said:
    • She ran great response and had good pull up to around 3k or 3.5k, but after that she just seemed out of juice in each gear, barely gaining in revs, even with pedal to the floor (just testing). Wiring or AFM or something...

    Check or recheck the TVS (AKA TPS).  You might be missing 27% of your enrichment.

    image.png

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    Could also be retarded timing.  Make sure timing advances with RPM.  You can check that with a light, non-driving.

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    On hot running, put a thermometer in the rad, get a direct reading of the water temps. Start cold so you don't open a hot rad. start car. let idle, confirm reading on gauge to thermometer.

    Mid range on gauge is 185f, just get it to that point and see what the thermometer says. IF its accurate then you have a problem. At 75f you should not go over 185f.

    possible problems

    1) bad or wrong T stat, beware, the bolts that hold the top cover on it can corrode and break upon removal. Don't go gorilla on it. If it does not want to come off you may need to heat them.

    2) plugged rad (look at the tubes for build up on the inside by the neck)

    3) low on coolant (incorrect burping of air may allow for poor flow or low coolant).

    4) bad pump (can corroded and lose pumping ability)

    5) Missing shroud (given the history it was prob "deleted" in some effort to go fast) This will show up when sitting in traffic, heats up, then temp drops once you are on your way.

    6) bad fan clutch

    7) slipping fan belt

    8) badly plugged up engine cooling system from years of abuse

    That's about all I can think of. If you have not already done this, at least check pump for lateral play in the shaft and/or weeping from the weep holes. grab the fan and try to shake it, some movement may be from the clutch, but if you think the pump shaft is moving, you should get a new pump. I would put a new pump in regardless unless I knew for sure when it was last done. And get one with a cast impeller not the stamped steel kind. I just like those better. Warning replacing the pump may result in BROKEN bolts, esp the 10mm  long one that goes into the engine block. I would research how to remove stuck bolts if it seems to resist at all. If you break that bolt the only cure is to remove the timing chain cover to get access and then its still not easy. The 3 long bolts on the water pump are what pull the TC case up tight against the water passages into the block, so you really want them all installed and torqued to spec.

     

    A good general service maybe all you need if its running hot. Consist of

    New pump

    New T stat

    flush, new coolant, new belts and hoses. maybe a new fan clutch if the old one is suspect at all.

     

     

     

     

     

     

     

     

    Edited by Dave WM

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    You can buy new connectors and pins from vintageconnections.com. You'll need a crimping tool and some patience but replacing those corroded spades will be much better than cleaning them. It's not hard to de-pin those connectors either...

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    Thanks for the info yall.  Hopefully the temperature thing is very simple and maybe just needs topped off and burped if I'm lucky.  I'll have to check the timing and TPS.  

    I managed to find the short in my hazards circuit (fun), and circumventing that wire fixed the hazards.  It shorted somewhere under the steering wheel on the way to the hazards flasher unit from the fuse box, visually couldn't find any damage.  Unfortunately the turn signals still don't work, so I'll be looking into that next so I can at least test drive with some confidence of not getting pulled over.

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    Well, I thought I was fixing a lot of wiring issues and removing a few shorts, but now I can't get her started at all. I went back and did the FSM ECU-removed tests and seems I don't have power from the EFI relay anymore.  I'll hopefully track this problem down soon.

    However, looking at some other wires in the engine bay, I found these guys (pic below) but couldn't seem to track them down in the FSM.  Either way, I'd really like to fully replace the connectors (or simply remove them).  The wires go from the positive side of battery and into the main harness via a solid blue and solid red wire.  But if you see in the picture, there's two small dirty green wires in the middle.  Are these fusible links? Anyone know what these wires are for? I thought the car only had 4 fusible links in the engine bay (which I have, not pictured), is there actually 6?

     

    IMG_20191031_175032.jpg

    Update: Scratch that, think i found it. Guess there is 6 total, image attached.  Looks like these may not be easily replaced looking at older posts.  Has everyone done a fusebox swap to address these?

    efi fusible.PNG

    Edited by S30Grit

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    You can check for power across the links, and measure resistance of the links.  Confirm that they're bad before you buy new parts.

    The two green links are the EFI links as you thought, but the wiring job alone might be the problem.

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    http://www.atlanticz.ca/zclub/techtips/fusiblelinks/index.html

    I've obtained a Cadillac Cetera fuse box from a forum member. I've yet to install though but it works well and is inexpensive according to him and I trust him 100%. I will post the info when I crack open my laptop.

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    The rating for the red links is too high.  Should be about 30 amps.  It's been discussed many times.  Red has replaced brown in popular Z lore for some unknown reason.  Brown is lower diameter than green, as shown in the FSM over many years.  Of course, it only becomes an issue if there's a short circuit.

    Edited by Zed Head

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    5 hours ago, Zed Head said:

    You can check for power across the links, and measure resistance of the links.  Confirm that they're bad before you buy new parts.

    The two green links are the EFI links as you thought, but the wiring job alone might be the problem.

    yeah, inspecting the connectors to the links, there's tons of corrosion.  And the wire ends/crimps are barely hanging on.  I'd rather just swap the links out.  I'll cut the wire back a little bit to see the condition of the wires. 

    I'll be putting two 40 amp in-line fuses in place of them.  I see the fuses vs fusible links has been a hotly debated item, but I haven't read any reports of cars starting on fire, so I'll go with the easier option

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    Sorry to be late with this and it seems you have a plan already but you can read over it for the future.  It's a brief description of the switch over he came up with.  We may put mine on in Nashville next year.  He said it's that simple.

    INSTALLING CATERA MAXIFUSE UNIT INTO A S30.pdf

     

    Edited by siteunseen

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    23 hours ago, siteunseen said:

    Sorry to be late with this and it seems you have a plan already but you can read over it for the future.  It's a brief description of the switch over he came up with.  We may put mine on in Nashville next year.  He said it's that simple.

     

    That does look ideal and clean.  I ended up using those large fuses commonly used for amplifier installs.  Easy to connect up, relatively good weather seal...

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    A final update on this topic:  After chasing down random wiring issues and corrosion, I found the core of the starting issue.  It was ironically simple: the aftermarket ignition relay was not wired correctly. If anyone else finds this thread in the future, the problem/solution is described below:

    The previous owner purchased this part (again a Zcardepot part), https://zcardepot.com/products/starter-relay-upgrade-replacement-280z#

    It looks like it comes pre-wired from zcardepot but I can't confirm that since I didn't order/install it.  If it was pre-wired then it's not plug and play, at least for the way my car is wired (78 280z) and requires swapping the two blue wires.

    Anyways, as many probably know, the "ignition relay" is basically two relays in one: one relay to power ACC (accessories) circuit and one relay for IG (EFI/fuel pump/etc).  In my case, the output of the relays was swapped.  Meaning that my EFI/Fuel Pump/etc were getting power when the ignition switch was outputting +12v for ACC, which is when the key is in ACC or ON position.  But as many know, with most cars, when you turn the key to "START", the ignition switch does NOT output to the ACC circuit 🤦‍♂️, explaining most of my issues...

    Therefore, the solution was to simply to swap the two output wires on ignition relay harness (the two blue wires in the harness). For reference, tests on page EF-27 from the FSM will help identify the problem (you'll find Fuel Pump relays aren't getting power when ignition is in START position).  Essentially the two  ignition relays should be wired as followed:

    •    IG relay: WB is the relay "output".  WR is constant +12v.  BW is relay on/off, connected to IG of ignition switch
    •    ACC relay: LW is the relay "output".  WR is constant +12v.  LR is relay on/off, connected to ACC or ignition switch

    Thanks again for everyone's help.  A lot of terminals a definitely a lot cleaner than before, ultimately the FSM wiring diagrams helped me backtrack through the wiring issues with the starter unplugged..

    Edited by S30Grit
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    Excellent find! Thanks for posting the solution

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