Dieing issue

[matthewstratton1449@gmail.]

So i just recently got my 280z to start and idle for about 5 seconds and then it dies while idling it runs rough any gas makes it die, fuel pressure tested at 38 psi and bleed down was slow and stayed at 20 psi.  have good spark new plugs,wires, and distributor. Coil primary resistance is 1,6 ohms which is more than the recommended 0.6 ohms so i dont know if thats a issue.  Cleaned all connections best i could and ran i new wire for the pin 1 on the ecu to the negative side of the coil along with swap ecus and drop resistor packs, i havent been able to verify timing yet waiting on a extra set of hands. just wanted to see if anyones had the problem before and knows some tricks. Also the car has sit for about a year prior to this first start ups, has fresh gas and new fuel pump and filter. I attached some videos of what it does

[Zed Head]

What year is it?  Could be the fuel pump switch in the AFM.  Or you might be starting on the cold start valve but not getting injection from the injectors.

Seems like you're looking at the right things.  Are all of the hoses intact on the engine?  PCV, valve cover, AFM, etc.  Is the AFM plugged in?  The plug has been known to fall off during assembly if you've removed it.

Many possibilities.  Give us some details on the car and engine.

[matthewstratton1449@gmail.]

Its a 1975, i have it manually wired for the fuel pump, all hoses are in good shape, the AFM is plugged in and good connection. 1975 Datsun 280z 2.8 got it just a couple weeks ago guy had it running year prior to being parked for the year and then it wouldn't run. I may pull injectors and see if their firing that way

[Zed Head]

1 minute ago, matthewstratton1449@gmail. said:

I may pull injectors and see if their firing that way

There are easier things to do before taking the injectors out.  Most of your troubleshooting is electrical on the EFI system.  You can check the injector opening signal with test lights.

 

[matthewstratton1449@gmail.]

so using that helpful manual i did a few tests and checks as of injector click im not hearing anything, when i tested the circuits the one attached cir 4 for injector 4 is reading barley any voltage compared to the rest that read about 12.3, also when i checked the relay i never got any click when i turned the key to on even laying under the dash with my hand and head near it i never felt or heard anything so im kinda stumped now i have 2 different ecus and drop resistor packs to swap back and forth with but nothing given much results.

[Zed Head]

Are you sure that the EFI harness wires are connected at the battery?  They have plastic connectors and connect to the negative and positive posts.  Don't get them mixed up.

Check your fusible link connections.  They get corroded and can lose continuity.  I think that there are two under a single plastic cover on 1975s, plus the one in the wire to the positive terminal.

Using your meter is the way to go though.  Make sure you have power where it should be and check grounds also.  Keep a list and record the actual numbers that you get.  Something will show up.  Most people with EFI have been where you are now.

[matthewstratton1449@gmail.]

yeah there connected however previous owner added new wires along with deleted the inline fuse, ill pull and clean the links and try that, been fixing and chasing alot of wire gremlins that the previous guy did when he pulled the engine

[Zed Head]

There's no good reason for only one injector to lose power at the ECU connector.  Power comes through the harness to the dropping resistors then through the injectors to the ECU connector.  Could be a bad injector.  Might explain the rough running.  But the engine should keep running on five.

Check the coolant (water) temperature circuit at the ECU connector, using the book as a guide.  It might be that it's disconnected and the engine is flooding.  If that sensor is bad or disconnected the ECU will add a lot of extra fuel.  Like you're in the Arctic.

[matthewstratton1449@gmail.]

so tested the water temp circuit and got nothing in ohms reading so im guessing the sensor is shot, connection and wires seem good re cleaned and tested again same result also today i haven't been able to get the car to start at all like the other-day so its weird, i think it was only starting with the cold start valve the other day and now being warmer maybe its not functioning. checked the links and there good and clean 

[Zed Head]

Check resistance at the sensor itself.  They don't really go bad often.  Many get replaced for no reason.  There are some bullet connectors in the harness between the ECU and the sensor that can come apart.  The sensor is the small one with the injector-type connector, not the big one.  The big one is the thermotime switch.  They're both on the thermostat housing.

You might pull a spark plug and see if it's gas-fouled.

All of these small things add up.  Keep knocking them down.

[matthewstratton1449@gmail.]

checked at the sensor still getting nothing on the ohms, gonna pull plugs here in a bit and check them

[Zed Head]

https://www.thezstore.com/page/TZS/PROD/11-3450