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New owner of '77 280z from Upstate SC


the_tool_man

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I haven't had much time to work on it yet.  But I fixed the clock.  I set it to the correct time and it magically started working, lol.  And I got the balky passenger door latch to work properly again.  It just needed a little lubrication.  I'm almost to the point of removing the AFM, having removed the intake hoses from it.  Tonight, I'll dive into the AFM.  If I get it running, I'll let it warm up and do an oil change.

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lucky dog - looks like a great find!

lots of great info on this site to get you going - i would do a full inspect, clean & deoxit to the electricals, every ground, plug, connector. start w/one harness at a time and go through each connection methodically. the efi system must have all components properly connected with all sensors reading the correct resistance for things to work correctly. this will save you hours of misdirected diagnostics as well as buying unnecessary parts.

let the fun begin!

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1 hour ago, the_tool_man said:

I haven't had much time to work on it yet.  But I fixed the clock.  I set it to the correct time and it magically started working, lol.  And I got the balky passenger door latch to work properly again.  It just needed a little lubrication.  I'm almost to the point of removing the AFM, having removed the intake hoses from it.  Tonight, I'll dive into the AFM.  If I get it running, I'll let it warm up and do an oil change.

Browse through these documents and download the EFI Book 1980.  http://www.classiczcars.com/files/category/4-manuals/  The 1977 FSM is available here (sorry Blue, it's the only one missing) - http://www.nicoclub.com/FSM/280z/  Download that also.

There may not anything wrong with your AFM, the fact that the wire in the intake kept the pump running shows that the switch is fine, not dirty.  EuroDat was suggesting that the spring pre-load may have been adjusted, causing the vane to stay closed, but any air leak in to the intake system might cause the same.  But you can tell if that's the case by inspecting the glue blob on the sprocket.  And you don't need to remove the AFM to do that.  It's actually easier to get the black cover off of the side with it installed.

Looks like it's in great shape.  Don't get ahead of yourself, taking things apart.  rossiz was on point, speaking from our collective experience.  It's the small things that will get you.  Poke around and ponder, there's quite a few things you've probably never seen before.

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I was going from my own experience which more than likely will be different for you. I have three spare AFM's and one in the car. They have ALL been tampered with. I tried two of the spares to test them and they were shocking until I calibrated them following the guide on the Alanticz website. Sad really, because I have yet to come across a problem where adjusting the AFM spring would solve it.

You can read on some websites how to set the spring about 5mm to 10mm back to increase the "performance". All they are doing is richening the mixture which is most probably lean due to ECU drift or corroded contacts etc.

The fist thing I did with mine was look at things (without pulling it apart) to get firmiliar with it all and read as much as I could.

BTW. If you suspect a vacuum leak, Fastwomen invented a nice little test to check this. It's called the Yogurt cup test. This is not original thread, but still informative.

 

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tool_man's car looks very "untampered with".  It even has the original plastic ties on the harness.  All I'm saying is check things out before going crazy.  He's removing the AFM, but what will he see with it in-hand, that he can't see with it on the car?

Here's something though - remove the distributor and give it a good work over before too much use.  The breaker plate bearings tend to rust to the rolling surface and break their plastic cage as vacuum tries to move them.

Here's another - buy some picks before trying to remove the plug from the AFM, or the injectors, or any of them.  They take a little bit of technique to remove..  

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4 hours ago, EuroDat said:

That looks like a VERY nice 280Z. Don't see many of them still with the original radio. Thats a good sign it has not been tinkered with too much.

Yeah, looks like a nice one, who was kept inside away from the elements. Can't see the underside, but on the pictures it looks fairly Original, only the sunroof must be added later on.

Great find. Clean it up, polish it some, and just enjoy it, keep it Original would be my advice

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Thanks for all the help.  I've still not carved out much time to work on the car.  I did get the mildew stains on the bottoms of the door cards cleaned up.  I "Lysoled" all of the hard surfaces inside the car and left the windows open to let it air out.

Regarding my learning, I've downloaded copies of the FSM, 280Z FI book, 1980 EFI bible (seems redundant), etc.  I read the first section of the 280Z FI book, and have read the AFM calibration website (though the HTML seems to be messed up, causing much of the text to overlap images toward the bottom of the page).  I've also ordered a Haynes manual, though it'll be somewhat redundant.  And I've spend a little time locating the various EFI components in the engine room (I love that the FSM calls it "engine room"), checking for loose connections or PO modifications (finding none of either).

My AFM appears to be un-tampered with.  I assume the black cover is glued on, and has to be pried off (amazingly, I haven't found instructions for that anywhere. I guess it's one of those intuitive things people just know).  One thing I did note was that when I start the car, it dies after a few seconds no matter what the throttle setting.  Whether idling or revved to 3000 rpm, it dies.  I can't imagine there would be a vacuum leak big enough to allow the AFM flap to remain closed at 3000 rpm.  That's easy to visually verify, once I arrange for a helper to start the car for me.  If it is staying closed, I think its stuck from being dirty, or held closed by a broken or misadjusted AFM.  If neither of those, I'll look for leaks.

Weekend plans include (in order of priority):

  1. Take the wheels off and get new tires installed (old ones are dry-rotted).
  2. Visually check operation of AFV flap.  If sticking, clean air passage and attempt to lubricate pivot.  What lube should I use here?  I don't want to foul electrical contacts inside the AFM.
  3. Depending upon the result, I'll open the AFV cover and go through visual inspection and calibration as advised.  One thing that wasn't clear to me.  Can the electrical measurements be made with the AFV in place?  It looked to me as if they cannot.
  4. If I remove the AFV to test it, I'll do the "yogurt cup" test to check for a vacuum leak.  Might as well while I can.
  5. While the wheels are off, I'll do a thorough inspection of the suspension and brakes.  Might get the brakes bled, too.  I suspect the rear cylinders are leaking, as the reservoir for the rear is low.  I already will have to rebuild the MC, as it is leaking out the back against the booster.  But that won't happen this weekend.

If I get all that done, I'll be pleasantly surprised.  My weekends get filled with lots of unplanned activity, lol.

Thanks again for the many suggestions.

Regards,

John.

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I would remove the AFM for cleaning the throat of the throttle body of carbon from the routing of the PVC hose with a toothbrush and lacquer thinner.  Then you could inspect and clean the AFM on your workbench, some cleaning tips can be found here

http://atlanticz.ca/zclub/techtips/EFI&fuel.htm

Be extra careful with the rubber connecting boots, they'll crack in a heartbeat when you start moving them around.  Maybe you could spray some type of lubricant on them the night before to help with removal and soften the rubber.  Don't forget about the ground wire on the AFM.  Good luck.

Oh yeah, here's the Tech Tips page.  Under "Electrical" you'll find the grounds that should be cleaned.

http://atlanticz.ca/index.php/tech-tips.html

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I think I would try a fuel pressure gauge first. Its easy to fit and non intrusive.

If the AFM is not activating the pump, you can listen to the pump behind the right rear wheel and hear if it stop just before the engine dies or uee some aligator clips and a test meter / test lamp on the pump to measure voltage.

You can also check the voltage at the nr 36 terminal on the fuel pump relay. Its easier to reach than the plug under the afm. That will tell you if the contacts are suplying voltage to the relay coil. You will see voltage when cranking and then it will fall away.

If you think its has a big vacuum leak. Spray some aerostart aroung the intake, flanges and hoses. If its starts revving up, that is a good indication you have a leak.

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You can do most of the EFI system testing at the ECU connector in the cabin.  That lets you test the wires to the components also.  The AFM black cover is a press fit, usually with a small amount of sealant around the edges. A wide blade scraper or screwdriver can be used to tweak the edges off until it comes free.  There's a bypass screw on the side of the AFM that is used to tune idle.  If it's far open it can let the AFM vane close.  Don't forget that the engine crankcase is connected to the intake system through the PCV, the valve and the hose from the valve cover.  So a split PCV hose or missing oil filler cap or leaking valve cover gasket can let air in.  Leaking injector seals can also be hard to diagnose.  If the wire in the AFM vane causes the pump to run then it seems like the fuel pump power circuit is in good shape.  The vane just isn't moving far enough.  Could be stuck.  One advantage of taking the AFM cover and starting the engine is that you can see the vane move or not move.  Most contact cleaners contain some lubrication.  WD-40 does also and it's made for electrical applications.

Lots of small things to check.  Try to get real numbers when you're testing, the FSM has a "continuity" check method that usually has to be re-run for real ohm measurements later.  

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