fuel injection troubles 77 zx

[forrestIII@hotm]

i have a 77 280zx and cant get the fuel pump to come on or the injectors to pulse. ignition system is working, can run on spray carb cleaner.changed ecu, but no luck. can anyone offer suggestions?

[m4xwellmurd3r]

On the 77 the fuel pump is triggered by the AFM flap moving iirc.

as for the injectors not firing, have you tried cleaning your Water Temp Sensor connections? if there's a short on those 2 wires, or if the connection is severed, it won't run at all. I can't remember if the 77 does this, but i know on my 78, the Oil Pressure sender controls the fuel pump.

[sblake01]

This thread might help. Note the 75-77 stuff as the 78 stuff doesn't apply to your car. Also open the link in post #6 in that thread:

http://www.classiczcars.com/forums/showthread.php?t=28935&highlight=fuel+pump

[TBK1]

The FI relay under the dash can also cause this!!

[CosmoZ]

As a electric/electronic guy, that chases electrical problems, I suggest you measure the voltage at the pump. There may be some logic somewhere that will not let the injectors fire without proper pressure. IF the pump has voltage, this is a pump problem or stoppage etc. If it does not ... get the schematics and go backwards looking for where it does stop. If there is a common point for supply for both the injectors ... that is suspect! If you have a friend who has the same setup, you can compare results.

Happy Hunting