Fuel Pump running non-stop, fuel delivery troubleshooting, won't start

[alejohndro5]

Hey guys, my name is Alex, I've just bought myself a 1976 280z 2+2, it has been sitting since '96 and I'm trying to get her running again. I've tested for spark, that works, new plugs and wires too, fuel lines aren't leaking, replaced the fuel filter, im getting fuel to the injectors but havent tested for pressure. as you've probably guessed, I cant get her to start yet.

 

Now I've been reading through this "280z fuel injection system theory and troubleshooting' book : http://www.xenons130.com/files/280zfuelinjectionbook.pdf

Very handy. The interesting thing I noticed at the top of page 3 is that the pump shouldn't run when the key is turned to the on position. Or am I misunderstanding this?

I read something about pushing the flap in the AFM to engage the pump, but that doesnt do anything for me as the pump is always running. I looked at the AFM anways, flap works, and closes, nothing in the way)

 

 

My pump runs (I can hear it) continuosly when the key is on acc, 'on', start; any position other than off. So is this normal? or should it build up the proper pressure and stop there until the engine starts? 

Today the engine wanted to turn over but after two coughs gave up. (starting system works, I'm pretty sure its a fuel delivery issue). Is it possible it might be flooding, with that pump pumping relentlesly?

 

Any and all help is appreciated, just trying to figure this thing out.

Edited August 5, 2013 by alejohndro5

[NewZed]

The fuel pressure regulator controls fuel pressure by bleeding off excess.  When the engine is running the fuel pump would normally be on all the time.  People bypass the switch in the AFM often, or it could be out of adjustment.  Pump on all the time won't affect how the engine runs.

 

Read the Engine Fuel chapter in the FSM if you really want to understand 1976 specifically.  The Fuel Injection Book and the Engine Fuel chapter together should make it easy to test most of the components from the ECU plug.  Spend an hour or two with a multimeter at the plug, with notes from the book and the chapter.  Even if you don't find anything wrong it won't be a waste of time.

 

 

http://www.nicoclub.com/FSM/