Assistance in diagnosing problems

Discussion in 'Technical' started by Hellsheep, Apr 3, 2016.

  1. Hellsheep

    Hellsheep Administrator Staff Member

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    G'day guys, first I'll introduce myself. I'm new around these parts, bought a '97 Auto 300ZX Twin Turbo (2+2 Targa Top) the other week at a low price. I've never really worked on cars before but I love reading so whilst it's been a learning curve I've already managed to do a bit thanks to useful guides on the internet/service manuals. The car definitely has issues and is currently unregistered but planning on getting it roadworthy again. Car has 104,000km on it.

    A bit of background; so far since I've owned it (about a week) it's had a fuel filter change (very easy), an oil filter and full oil change, I've ripped off the crappy HKS "death mushrooms" that were falling to bits, planning on bolting the Apexi Power intake directly to the AFM (already ordered, just waiting for parts)

    I am awaiting pricing for a set of new PFR6B-11B spark plugs from Repco (apparently they have to be ordered from Japan as they don't stock them locally in Darwin)

    I had brake lights stuck on and thanks to the good folk here I managed to find the plastic brake stoppers disintegrated on my floor so I'm awaiting pricing from Nissan spare parts on those (as everyone else wants to charge 50-100 shipping from the US... no thanks for a $5 part)

    The car likely hasn't had its 100,000km service, or much servicing at all I expect. So my to do list includes water pump replacement and timing belt + all the other 100k recommended parts but I'll have to do that over time.

    The TPS was sitting at 0.22v so I've now adjusted and the closest I can get is 0.44v. (I've got an ECUTalk LCD for checking the values thankfully)

    Now to the issues;

    The brakes are pretty average, when the car is off I can push the brake peddle almost to the floor, when the car turns on, it goes flat to the floor, if I pump it in quick succession it's almost like there is no hydraulic pressure as I can push it in quite far, the brakes aren't very good and don't seem to engage very well until pushed in very far (though it's not overly hard to push the peddle in, so I don't think it's the brake booster but I may be wrong?) With the brakes in this state I don't even drive it as I wouldn't trust me to be able to stop from even 60km/h in a reasonable distance. I'm pretty close to getting a mechanic to come have a look at my place however I thought I'd try here first to see if anyone has any suggestions.

    2nd issue, which may somehow be related to the brake issue is I believe there may be some sort of vacuum leak. I've read a fair bit about this and seen a few methods of testing used. The only reason I believe this is because yesterday I was having issues with the car at running temp, revving it and the car would stall and not idle. This is why I fixed the TPS however I haven't tested if it was just a TPS issue yet as I haven't had a chance to do the same test again (hopefully will tomorrow)

    3rd issue is there is some fluid leaking from the car, I've got a mat under it at the moment and the colour of the fluid is reddish. It appears to be leaking on the passenger side of the engine somewhere as it ends up on the passenger side of the mat on the floor. (Wondering if it's brake fluid, then it'd explain the issue with brakes being bad?)

    I apologise for the long winded post! As I said I'm pretty new to any work on cars so I'm sure I'll have lots of questions, but give me the chance to learn and I'll make every effort to take your advice on board. Oh also, I've pulled the ECU codes, no errors.

    Cheers in advance.
     
  2. gmbrezzo

    gmbrezzo Moderator Staff Member

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    Hi and welcome to the forum.
    We don't see to many members from NT
    We have a few members here that can help with parts supply, plus keep an eye out for members doing part outs (where's Jamie when you need him), also a good way to stock up.
    Some of the guys are: Rob260 (RGS Performance), A-Bris-Z (CarCraze), Jordz (Z32 Parts), UNIQUE ZED (Unique Auto Sports)
    These guys are all trusted Zed owners and suppliers.
    Can give you more contacts if you require later.

    0.44v is the service manual setting.
    I was told by a trusted Zed mechanic to set mine at 0.42v. This has worked very well for me and is still set at that today.

    Sounds like air or moisture in the line.
    Do a full brake bleed to rule that out.

    If there was a large vacuum leak then the brakes would be hard to push and you would also have a massive idle problem.
    A small vac leak would cause idle issues. Do a Boost/Leak test.
    You may have a brake master cylinder problem.

    Check to see what colour the brake fluid is to see if it matches.
    If its transmission fluid it will be slippery to the touch. If its brake fluid it will feel more "watery" to the touch. Plus the smell is also a good give away.

    No problem in long stories as that also helps in a big way.
    Way better than a one liner "my brakes don't work"
    Welcome to the Zed way of life and get ready to lower your bank savings :eek:
    5-6 years ago I lifted my first Zed bonnet, and promptly closed it with the word "Oh hell no!".
    This forum with its knowledge base and helpful members have gotten me to where I am today - Broke and a heap of great friends.
     
  3. Fists

    Fists Well-Known Member

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    For the spark plugs have a look at the sellers listed in this thread, it is unlikely repco will get back to with a price that isn't comparable to a new car. http://www.aus300zx.com/forum/showthread.php?t=335159

    For the brakes they likely just need to be bled, some fresh DOT 3 or DOT 4 fluid and a good bleed should make a good difference although it is possible there is a faulty seal in the system drawing in air and making them soft.

    Red fluid is generally DEX 3 automatic transmission fluid, used in both the transmission and the powersteering fluid. I'm not very familiar with the auto cars but I think their transmission oil lines run on the driver's side so I would be guessing power steering leak from one of the return lines or the hicas lines that run around the bottom of the bay on the cross-member. Give the area a good clean then see if you can see where it starts leaking from. You can also try turning the wheel or putting the transmission into gear to see if one or the other accelerates the leak.

    Vac leaks and idle problems are always annoying to track down in these cars, let us know if the tps setting makes any difference.
     
  4. scottyoz1962

    scottyoz1962 Active Member

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    As for the plugs, tell the idiot they don't have to order them from Japan, order them from their warehouse, also they are laser platinum plugs, and you don't really need them, normal plugs are fine unless you running fulli sik boost with a gazillion killawasps so the ordinary plugs are fine or just get the bosch plugs in platinum cost about $50 at repco.

    The green stoppers aka lollies as some nissan spare parts guys call them are about $12 each, you'll need 2 of them and they are compatible for memory with several other nissans, if you can get hold of John aka brisz he has the nissan fast parts list. Also if your nice to him and ask nicely and give him your vin# and chassis# etc he'll tell you if it is a genuine 1997 or earlier, as it could have been imported and complied in 1997 .

    If your going to do the 100k service , do it all in one go the kit from CarCraze is about $700-800 ! don't quote me on that actually i looked it up http://www.carcraze.com.au/genuine-nissan-300zx-z32-vg30-timing-belt-kit-base $749.50. Whilst you have the car ready to do the 100k job, do a full plenum pull and delete. Saves time and money.
     
  5. zed96

    zed96 Member

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    supercheap auto can also source you those plugs straight from NGK. They will be able to quote you straight off their system.
     
  6. Hellsheep

    Hellsheep Administrator Staff Member

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    G'day all,

    Thanks for the advice. Rather than spending a while quoting everyone I'll just say an overall thank you.

    At least I can add to the NT numbers a bit since we seem to be a minority.

    I've already hit Rob up for some stuff and plan to get some more from him in a little while :)

    Good to see that I've got the TPS pretty close to what's recommended as well so cheers for that!

    I've got a few plans for the brakes, going to do some testing on the master cylinder to see if I can get pressure there, have been cleaning up under the car and inside the engine bay where I can to see if I can identify the leaks but the leaky fluid appears to be transmission or power steering rather than brake fluid. Will also look at doing a full bleed/new fluid see how I go with that.

    Need to do a boost/leak test as well which I'll add to my list.

    The TPS setting definitely seems to have made some difference, car doesn't stall anymore, however I do notice something, the stock oil pressure gauge sits around the 4 mark, oil pressure picks up when I give it a bit of a rev, but when I let it back to idle it still drops slightly lower than idle (drops to around 550-650 then back up to 720-750) and the oil pressure drops lower than the 4 on the stock pressure gauge then picks back up again, is this normal or does this indicate an oil pressure issue or something else?

    Decided to get some iridium plugs locally cheaper than Repco quoted me on the PFR6B-11B plugs. I'd rather do things right and not have to replace plugs again later on once everything else is running even better.

    Supercheap up here told me they can't stock them. They can only stock the PFR6B-11, the 11B is unable to be ordered apparently up here (don't ask me why, probably them just not looking hard enough)

    Again,

    Thanks for all the advice. :)
     
  7. Madcow

    Madcow Active Member

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    Oil pump is run off the crank. So as the crank speed picks up, so will the oil pressure.
     
  8. IB

    IB ?????

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    The PFR6B-11B* plugs were for US delivered TT's. JDM TT's had PFR6B-11 plugs from factory.

    * Might have actually been PFR5B-11B (a hotter plug)
     
    Last edited: Apr 5, 2016
  9. Hellsheep

    Hellsheep Administrator Staff Member

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    Thanks for that, but will the oil pressure also drop lower than its previous pressure at idle before revving or should it drop back to the same pressure?

    Thanks for that, I went and got some iridium replacements instead from Supercheap today that they had in stock. Will see how these go.
     
  10. Madcow

    Madcow Active Member

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    Oil changes thickness as it heates up. So as the oil gets hotter it gets thinner, needing less pressure to push it around.

    All the gauges on the 300zx are known to be inaccurate. Dont trust them for much, this includes the water temp.
     
  11. Hellsheep

    Hellsheep Administrator Staff Member

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    Cool thanks mate :) guess I've got some more reading to do!
     
  12. Hellsheep

    Hellsheep Administrator Staff Member

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    Bit of a double post here, I spent 3 hours tonight in the dark (my bright work lights blew both globes...) With only a torch and a phone light installing the new iridium plugs I bought locally from super cheap today. Everything came out relatively easily. Had a few issues with how long the tools need to be to reach the plugs but got there in the end. Everything also went back together pretty easily and the car started (always a good sign eh?) And seemed to be running pretty well however being midnight I didn't want to leave the car running long and awake the neighbours. I did however notice on the passenger side plug under the balance tube there was a fair amount of oil on the thread, didn't seem to be any on the electrode at all. I did a bit of research and someone reckons it's probably a leaky gasket or something similar. Same on the driver's side but less oil.

    Is it something I should be looking at sooner rather than later?
     
  13. Madcow

    Madcow Active Member

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    Oil leaks are never a good thing, they get messy pretty quick.

    for now clean it all up, and just keep an eye on it. it might be a slow leak that wont need attention straight away. if it keeps leaking to the point its pooling, it will need to be fixed right away. My guess is it will be the intake side. They have a rubber seal which you can just replace, problem is to get to it can take some time. once you have done it a few times it will get faster, first time can take a couple of hours while you work out where all the bolts are.
     
  14. Hellsheep

    Hellsheep Administrator Staff Member

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    Excellent thanks for that!
     
  15. Hellsheep

    Hellsheep Administrator Staff Member

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    Hey again guys, I got the chance to start the car today and put some fresh fuel in. Let it heat up a bit then took this small video showing some readings from the ecu. How do these look?
    https://youtu.be/TCFbE2zmjjE
     
  16. Fists

    Fists Well-Known Member

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    Voltage is low and looks like it drops with revs so alternator is probably struggling a fair bit. Does it have any shiny aluminium pulleys for the drive belts or are they the stock iron ones?

    Everything else looks good, can't check the O2 sensors while cold though.
     
  17. Hellsheep

    Hellsheep Administrator Staff Member

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    Good question but I suspect stock. What should the voltage be? Is there a particular reason you think would cause the alternator to struggle? Also what temp can I check o2 and what should the readings be?

    Also, I found some interesting things while bleeding the brakes tonight. Right rear rotor(?) Is missing a threaded stud and lug nut entirely. Left rear is missing a lug nut and has some random lug nut that doesn't really fit properly and also has one stud that looks new and is shorter than the others..... It gets better. I took the front left off andwas trying to bleed it, couldn't for the life of me figure out why no fluid was coming out. I was starting to think maybe I was doing it wrong. Turns out the brake line isn't connected to the front left calipers at all and is plugged with a bolt instead. No wonder why my brakes don't work very well. Didn't bother with the front right after I saw that. But I did see the front right had a large flat head screw that is meant to have a spring type thing hooked into it on the back of the caliper? It was half unscrewed and hanging out. That brake also squeaks like crazy and feels way more tight than the others. I read a bit about brakes but I think fixing them might be a bit out of my skill set and possibly lack of tools too.
     
  18. gmbrezzo

    gmbrezzo Moderator Staff Member

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    Holly cow. Those comments on the brakes and wheels.
    How were you able to stop with only one brake on the front and not lock up all the time?
    Please get those fixed as a Very high priority. I'm sure there are some guys doing a part-out on here at the moment.
    Maybe that disconnected calliper could be seized.

    Battery voltage is a guideline. Anything above 12.5 is showing a charge.
    As long as sitting voltage (engine not running) is 12.5 or above, and when you start it raises to 13+ volts the charging system is working.
    Probably could be better, but still in the OK region.

    Once the car reaches running temp (gauge half way) then holding the revs at 2000+ (2500) your O2's should fluctuate evenly and in unison.
    If they are vastly different readings then you may have a damaged O2 sensor.
     
  19. East Coast Z

    East Coast Z Well-Known Member

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    Re: Spark Plugs

    Platinum tipped type plug types.

    US NA:
    Standard: PFR6B-11
    Hot: PFR5B-11
    Cold: PFR7B-11

    US Twin Turbo:
    Standard: PFR5B-11B
    Hot: PFR5B-11B
    Cold: PFR6B-11B / PFR6B-11

    Australian NA:
    Same as above.

    Euro Twin Turbo:
    Standard: PFR6B-11C
    Hot: PFR5B-11C
    Cold: PFR7B-11C

    P - Platinum
    F - 14.0mm thread x 19.0mm fitted with a Gasket & 16.0mm Hex size.
    R - Resistor type
    5 - Heat range
    B - Special Design Firing End Construction
    11 - 1.1mm Gap
    B - Suffix

    Torque on all plugs: 14 to 22 ft/lbs
     
    Last edited: Apr 7, 2016
  20. Hellsheep

    Hellsheep Administrator Staff Member

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    I knew of a brake issue when I bought the car, I was told it's likely a faulty brake booster though by the guy I bought if from. Because of this I got the car towed to my house and I haven't driven it since. I wasn't going to risk driving it until I knew the brakes were working optimally. I still don't drive the car. I have my other car as my daily driver. Glad I did the smart thing and didn't drive with it in the state it was in. The calipers on the two fronts loom much bigger than the rear and they don't seem to be genuine Nissan from what I can tell. The large BBS rims on the car have also scraped away some paint and metal from where it appears they were rubbing on the outer part of the caliper. I might just get then replaced. I suspect though if im going to invest in something new I should probably get the rotors machined too if they need it?

    Also thanks for that I'll give the o2 a try tonight
     

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