All injectors with key in on position show 12.6 volts on one wire and zero on the other
all injectors full open when key is in the on position
shouldn’t the voltage be below that like 4volts or lower cause the dropping resistors?

 

No, the dropping resistor limits the amount of current that the injectors draw. Resistors do not drop voltage across them, just limit the current flow. The 1975 to 1983 280z/zx injectors are low impedance injectors so they will draw too much current if it is not restricted by the resistors. Yes all of the injectors will have battery voltage on one side, you have to disconnect all 6 injectors at the same time to properly test this. The dropping resistor was removed in the 1982 and 1983 cars because the ECU was modified to handle the job of the dropping resistors. You can mix and match injectors in all years but the 1982/83 ECU cant be used in 79-81 cars and the 79-81 ECU cant be used in the 82-83 cars
The ECU grounds the injectors to fire them so none of your injectors are "full open" with the key on. FYI all of the injectors fire at the same time, "Gang Fire". The ECU counts how many times the ignition coil fires and every third time the ignition coil fires, all of the injectors fire.

 

Thank you for your reply have been working on car for few months with same issue

if what your saying is correct why on page 19 of the FSM does it say drop resistors drop voltage from source to a quarter of the voltage?

why would all injectors fire at same time ? There is two wires and I think I understand that the ecu pulses each yet mine are all open

Also, when keys in the on position, all injectors are fully open and flood

I have tested voltage at all injectors one side wire is at 12.6 on all 6 and the other side is zero on all 6 with key on

have went through entire FSM test sheets all checked to spec

 

Have you checked the ground wire on the injectors. Use OHM and you should get no (open) reading, this check is in the FSM, page 22 of the engine fuel section. Disconnect the 35 pin at the ECU (disconnect the battery first!) and check for continuity between the non-positive side of the injector connector and any body ground point. You should get no reading, not zero but infinity. If you do show continuity you have a short to ground somewhere between the injector negative wires and the ECU. It only takes 1 bad wire of the 6 to be grounded to mess them all up as they are all connected in the ECU. The ground wires at the ECU are 2,3,5,6,7,8- yes 4 is skipped and used for the cold start and thermo-time switch.
Here is some good reading and information. Its the EFI Bible:
EFI Bible

 

Just checked them now they all have zero ohms on ground side ….

really appreciate your direction and help !!!!

I am lost at least your helping look down a path!

 

there is a difference between zero ohms and infinity. Zero shows that there is a connection between the wire you are checking and the body ground. Infinity shows that there is no connection between body and ground wire(s). So you showing zero would indicated that there is something going to body ground instead of ECU doing the grounding. Correct?
Your work book page does not show pin 2,3,5,6,7,8. I don't know if you know this but the sideways 8, like shown on pin 24 and 29 is the symbol for infinity or no connection (0pen circuit).

 

This is the meter I have this is the setting I set it on it shows one now and would beep and show zero when checking each ground side of injector and female side of 32 pin at the numbers you said to

 

No, one side to pin 2,3,5,6,7,8 and the other to body ground. The meter should not change as if it is connected to nothing. There should be no reading. Zero OHMs is a reading meaning there is little to no resistance between the two points of contact where you have your probes. Infinity is no reading meaning no current can flow between the probes 2 points of contact. Infinity is what your meter reads when it is not connected to anything, no current can flow.
The negative side of the injector wire should have no connection to the body. All of the injectors have to be disconnected and the 35 pin has to be disconnected.
The ECU is the on off switch for the injectors. The ECU connects the injectors to ground to complete the circuit and open them. I still dont understand how you know your injectors are open with the key on. Do you have the fuel rail removed and have constant flow of fuel out of them? IF this was true, your engine would be full of fuel. Literally the cylinders would be hydro locked and you would not be able to rotate the engine.

 

Have hydro locked twice not fun !

filled oil pan and oil

so I have all new injectors in the holes now
Have extra ones to check each plug with off the engine not Attached to rail so I can test the open and closed when key on I am able to blow through them
when key off I can’t

 

You have a short to ground on the negative side of your injectors. They should not be open with the key on. Again, disconnect all the injectors. Disconnect the 35 pin at ECU. One probe on the negative wire in your injector connector and one probe to the car body. The meter should not change (infinity). If it changes and reads zero (thats a OHM value) you have a shorted negative wire to ground somewhere between one of the injectors and the 35 pin.

 

Headed to my shop now to try your input on the car
really appreciate your help ! You have no idea how much man

so to be clear one side to body not to the engine and the other on the ground side of plug wire for each injector
oh and with 32 pin unplugged

 

OK, unplug the 32 pin did the ohms test on all ground plug connectors at each injector to the body by touching one probe on the negative wire in the injector connector and one probe to the car body. The meter did not change, none of them showed a change.

when 32 pin is un plugged, we also made sure to check and see if there is still power at the plugs for injectors and it’s not there after it’s unplugged

also have unplugged each item (listed below) while testing for power at the injectors

thermal time switch
Oil, pressure switch
ic ignition unit
Cold start valve
throttle valve switch

to see if any of these being unplugged would change the readings at the injector plugs while reading 12.6 volts continuously

 

I did find an issue at 28 could that cause all this
fuel 2 relays
in this car there is two

 

So with the 35 pin disconnected the battery hooked up and the key on you no longer have power at the injector plug ?

 

That is correct

 

Got your message I’m not going to be with the car for couple days now due to family things
will text you soon though
also waiting for new dropping resistors I ordered
I’m feeling like Ecu is bad even though I sent it in for repair and they said it was repaired that they found a charging side repair …. Not sure what that means
or Coil or distributor issue ?
im so stumped
I’ll be in touch though thnx. Again

 

That's not right. Your ECU does not supply power to the injectors or the EFI relay, your ignition switch powers the EFI relay and that relay sends 12V to the injectors. Has someone messed with the wire system on the car?
I am starting to think that your ECU is bad. Figure out why you dont have power to the injectors with the ECU disconnected, that will be the key to figuring this out.
If you can get 12v to the injectors with the ECU disconnected and the injectors stay closed you don't have a bad ground wire on the injectors. If the injectors re-open once you reconnect the ECU I would say the ECU is bad.
Here is the wire diagram for the power to injectors