280Z Requires Starting Fluid for Cold Starts

[Dave WM]

Video of the problem is always good. how about a video of your cold start procedure with the starting fluid. Be sure to include things like engine temps etc..

[Zed Head]

Another guess.  I went back to the first post but can't be sure.  How old is the fuel in the tank?  Old fuel will often lost volatility.  Sometimes it will last for years, sometimes it goes bad in months.  

[S30Grit]

3 hours ago, Captain Obvious said:

Yes, I would agree that 15+ seconds of continuous cranking is disconcerting and not something that you would want to be necessary. But I'm trying to make sure I have an accurate handle on the problem.

Sure thing, I'll give it a go.  I don't have easy access to a battery tender where I'm at, so for this test I may also run jumper cables to the car.  Testing two variables at once, but still useful data I think.

[S30Grit]

44 minutes ago, Zed Head said:

Another guess.  I went back to the first post but can't be sure.  How old is the fuel in the tank?  Old fuel will often lost volatility.  Sometimes it will last for years, sometimes it goes bad in months.  

That was definitely a problem when I first got the car, but the mechanic drained a good amount of fuel and put in fresh fuel about 2-3 weeks ago.

[Captain Obvious]

8 hours ago, S30Grit said:

Sure thing, I'll give it a go.  I don't have easy access to a battery tender where I'm at, so for this test I may also run jumper cables to the car.

Yeah, I wouldn't want to have to crank twenty seconds every day, but just once to see if it will eventually start without the ether could potentially be a helpful data point.

[S30Grit]

Had a few hours to work on it today, spent most of it putting the new injectors in.  I came to a few realizations:

1) (Rant Warning). I learned to NOT to trust parts willy-nilly from zcardepot.com.  I purchased the injector holders on their site, https://zcardepot.com/products/fuel-injector-base-holder-trigger-280z-280zx-75-83?_pos=5&_sid=a8aee91be&_ss=r# because one of mine was cracked.  I figured if I ordered them from somewhere, surely a Z parts specialty store would sell something that fit.  NOPE.  My two-piece OEM holders fit perfectly and they screw right in.  These cheap parts from "Standard Motor Products" (which isn't named on the zcardepot product page) do not align with the screw holes on the intake manifold.  It's close to aligning, but too far off to even get a thread in.  Of course I had no drill/bits with me to bore them out, so I used some sand paper and a screw to 'bore' one of them out enough to barely fit. I cracked the other messing around with it.  Frustrating to say the least. +1 for the OEM purchasers... Makes me scared about buying other parts for the Z.

2) CSV was definitely gunked up. Cleaned, soaked, and clicked the solenoid with some injector cleaner.  It sprays now when given 12v w/fuel pressure.  Likely too warm today for the thermotine to trigger it anyway (75F).  And as discussed previously, CSV most likely isn't cause of my starting issues.

3) Battery voltage while car was off is around 12.2V.  When cranking, it drops to around 10.25V.  Battery isn't fully charged from all the cranking it's done lately, but these numbers still seem normal.  https://tontio.com/auto-guides/car-battery/car-battery-voltage/

4) It was getting dark and probably around 60-65F outside when I tried to start it for the first time today.  I couldn't even get it to start on starting fluid (only sputtered).  This is probably the coldest outside temp I've tried to start it (unsure if related).  Also it maybe has some air in the fuel lines that needs to clear out, and since my injectors aren't firing (#5 below), not sure the air was getting pushed out.

5) To sanity check the mechanics work, I checked one of the injector wiring harnesses.  While cranking, an LED on the harness did NOT turn on.  While messing with the key in the ignition, I saw the LED flicker 1 time, not even a "pulse" but a flicker.  I'm still determined this is the cause.  Something in the ignition assembly (even tho it's new) or other EFI wiring must not be connected/grounded right. 

I found it bizarre with the key in the ON position, and the motor not started: both pins on the injector harness had +12 volts.  Either pin would light up a test light with the other end grounded.  One pin is supposed to have +12v at all times, but I thought the other pin should be floating, waiting to ground pulse to complete the circuit.  Tomorrow I'll be doing FSM tests related to this circuit tomorrow.

[Captain Obvious]

The situation where you're getting +12 on both sides of the injectors is normal. It only takes a small amount of current to light up the test light and you'll pull that small amount through the injector on the floating side. It's not enough current to click the injector, but it'll pull enough to light the test light,

In fact, you'll see that same situation even if you pull the connector off the injector completely. You'll pull current through one of the other injectors. Like this:

[Zed Head]

On 10/18/2019 at 8:14 PM, Zed Head said:

Take the black cover off of the side of the AFM.  It is just a press fit with some light sealant to hold it in place.  There is a damper weight that moves with the AFM vane.  If you move the weight the vane will move, and vice-versa.  It should start moving as soon as the engine turns over.

I still think that this is worth doing.  If the vane is stuck you'll get less fuel.  It's not uncommon, I think that confirming the vane isn't stuck is one of the checks in the FSM.

As far as the starting fluid non-start is concerned, where are you squirting the fluid?  You should squirt it in to the manifold after the throttle blade for best effect.

[Patcon]

A fully charged battery is 12.6v, so you need to get it charged up. It also drops a lot when cranking, how old is the battery. Probably not a direct cause but EFI and ignition systems don't like low voltage. Things get wonky when the voltage drops too much

[Zed Head]

Another guess and one that happened to me except that it happened when things got hot.  The EFI relay coil would get an open circuit and not actuate the relay during starting.  Just crank, crank, no start.  You could jump the EFI relay pins as a test.  

One more - you say that you're not getting the injector test lights flashing during starting.  This could also be caused by loss of injector power.  Put a meter on an injector plug and see if you lose power during starting.

The best way to solve these EFI problems is with a detailed list of tests and knocking them off one by one.

[S30Grit]

12 hours ago, Captain Obvious said:

The situation where you're getting +12 on both sides of the injectors is normal.

Gotcha, good to know, makes sense as it was a lower power LED bulb.

 

10 hours ago, Zed Head said:

I still think that this is worth doing.  If the vane is stuck you'll get less fuel.  It's not uncommon, I think that confirming the vane isn't stuck is one of the checks in the FSM.

As far as the starting fluid non-start is concerned, where are you squirting the fluid?  You should squirt it in to the manifold after the throttle blade for best effect.

A few things on the AFM.  Relatively sure the AFM is actually a new unit (more parts someone threw at it).  The vane opens with ease by hand.  I'm working on my own and can't watch it during startup.  But I'm actually spraying the starter fluid in a tube connected to the AFM, and since I'm getting a sputter at least, I think I can assume the vane is opening at least some.

 

10 hours ago, Patcon said:

A fully charged battery is 12.6v, so you need to get it charged up. It also drops a lot when cranking, how old is the battery. Probably not a direct cause but EFI and ignition systems don't like low voltage. Things get wonky when the voltage drops too much

Battery is 10 months old, spent most of it's life on a battery tender in a garage.  I tried the jumper cable start (my working car has a solid 12.8V or so) and didn't make a difference in terms of starting. I also tried starting for 15 seconds non-stop in the jumper cable config and no dice.

 

[Zed Head]

10 hours ago, Zed Head said:

One more - you say that you're not getting the injector test lights flashing during starting.  This could also be caused by loss of injector power.  Put a meter on an injector plug and see if you lose power during starting.

Grit, I'm not really suggesting things that you should do on a whim, I'm suggesting things that I would do if I had your problem.  I'd use a mirror to see the AFM.